Anyone listen to Zu Audio's Definition Mk3?

Glory,

I live in an area with fairly dirty power. I've investigated a lot of power conditioning and of course, all choices sound different and none so far have been completely positive in their effects. But I haven't by any means auditioned a comprehensive list of candidate conditioners. Currently my sources and preamplification are fed by balanced power/isolation transformers, and my power amps get lightly filtered inductorless AC conditioning. Sometimes I plug the power amps directly into the wall just to remind myself of the difference. I am considering BPT or Furman full balanced power isolation for both whole systems, including amperage capacity for power amps, this year.

My gear in both systems rests on custom made solid maple tables, each identical at 6' long, 23" deep, with total height of 17-3/4". The top surface of these tables is an expanse of lamintated 1-1/2" thick solid maple boards, for 3" total tabletop thickness. The second shelf under neath is solid 1-1/2" thick solid maple boards. The legs are 2-1/2" x 2-1/2" solid maple. The bottom of each leg has a 2" diameter x 2" tall height-adjustable brass cone. The cone points rest on Herbie's Cone Decoupling Gliders (brass receptor/stiff elastomer/teflo). My turntables sit on the top 3" layer, on Aurios Media Bearings. My phono & line preamps, and SUTs also sit on this layer, on Herbie's Grungbuster Dots. My optical disc players sit on the lower 1-1/2" thick shelf on Aurios Media Bearings. I live in a slab house, so this being California, the turntables are great for listening to the planet if I remove the Aurios. Better for music with the Aurios in place. But also, being a slab house, footing is very firm for everything.

Zu crossoverless design: The simple answer is there's no splitter between the power amp outputs and the main driver(s). The more complete answer: There are variances in internal wiring from model to model in Zu's line, but the essentials are all shared. Every Zu speaker is architected around their 10" FRD (Full Range Driver), which some sticklers will insist should be referred to as a "wideband driver" or "widebander." In each Zu speaker, the widebander is handles the frequency range of about 38Hz - 12kHz. In the simple 2-driver speakers, the power amp will "see" the widebander's voice coil directly. In Definition, Omen Def, Dominance, there's a little more going on schematically. But nevertheless, unlike a conventional multi-driver louspeaker incorporating a passive crossover, the amplifier signal is NOT passed through a passive crossover that splits signal before the widebander gets signal. So the power-eating inefficiencies and phase non-linearities, not to mention the tonal colorations and distortions of conventional passive crossovers are not introduced. Instead, a supertweeter is included for top end sparkle and harmonic completeness, and it is rolled in by a gentle passive high-pass filter roughly inverse to the natural acoustic roll-off of the top end response of the widebander. No circuitry enforces the roll-off of the widebander. In Definition and Dominance, which include extended bass performance through built-in powered sub-woofers, input to the sub-amp comes from a fixed low-pass filter that in Def 1 & 2 approxomated its roll-in to complement the natural acoustic roll-off of the widebander's low end response, with an amp level control added. In Def4 and Dominance, this low pass filter is now active and adjustable within specific ranges, for more precise matching of bass performance to a wider range of rooms and placement conditions. The key point is that the main driver -- the FRD or the widebander -- that outputs 90% of the music content that defines your listening experience, is receiving an unfiltered signal that's undisturbed by an intervening crossover. High and low pass filters for frequency extension simply complement the natural roll-offs of the widebander's response.

Phil

I have my Def4s. I'll be posting a review in a few days, with comments relative to Def 1.5, Def2 and Def2 w/ HO drivers.

Phil

Yes, Glory has it right. I've been too busy listening to my Def4s to take time to write about them. I bought about 50 more CDs and vinyl discs since they were delivered, and I'm plowing through my thousands of existing discs. It's cutting into my work productivity!

Here are the short strokes, while I get my full narrative together:

To understand Def 4 you have to know Def 1 and 2. I'll write about this later. The basics however are apparent regardless of your historical exposure to Zu.

1/ Top to bottom, Def 4 is for the first time a Definition-archtecture speaker that has the holistic charcter of Druid, with Definition's accuracy and scale. Its tone, speed and dynamic characteristics are now fully uniform top to bottom. In prior versions, the dual FRDs, super tweeter and the sub-bass array left traces of their independence. No more.

2/ Def4 soundstage is as wide and deep as your room allows, and will go beyond to serve the dimensional characteristics of the music performance recorded. For anything from a Blu-ray movie soundtrack to a full orchestra to a trio or solo performer in an intimate space, spatial representations are closer to the perception of live performance than in any Zu speaker to-date (though I haven't yet heard Dominance).

3/ Even in a tricky room, the new 12" cast-basket down-firing sub-bass driver and its driving amplifier more evenly loads a room with bass, with fewer resonance, bass-piling and reflective problems than the older and once-excellent 4x10" back-firing sub-bass line array on Def 1&2. Most of the bass resonance problems that I've in the past just had to listen through in my main room, are mitigated to the point of irrelevance. Bass is prodigious when the recording calls for it, but in all cases is reproduced with higher definition and charcter unique to the given bass instrument and the player's style, than in prior versions.

4/ Top to bottom transient uniformity is unprecedented for a dynamic speaker. Def4 has electrostatic-like speed and uniformity, while retaining the punchy heft of a responsive magnet-motor cone speaker.

5/ The inclusion of the Radian compression supertweeter is a very large advance over prior Definitions, if your high frequency hearing is still intact. It is extended, liquid-smooth, fast and not beamy. It is what Definition needed from Day 1. Similarly, the nano-treated main drivers are responsive and transparent to a new level of revelation because even further stiffness has been achieved in the cones, with only a fraction of the added mass of prior treatments. As I understand it, only around a gram or less of treatment compound is used now per driver. You hear it, in speed, attack, articulation and tone.

6/ As I'll elaborate in a more complete assessment, cabinet talk is suppressed yet again over the prior version, sharply reducing the tonal artifacts introduced by high SPLs in prior Definitions.

7/ An unexpected consequence of all this attention to advancement: somehow and counterintuitive to landing a more revealing speaker, regular Redbook CDs are more listenable and satisfying than ever before, without any change to my sources. I expected a more transparent transducer to render older, or more compressed or generally poor CDs to challenge my tolerance for listening to them. But the reverse is true. These speakers have me mining deeper into my CD collection than in quite awhile. Vinyl gets its due but I have a lot of music unavailable on vinyl, and I'm enjoying all of it more.

8/ Tonal integrity and holistic realism remain evident in the bursty, one-voice Zu way, but beyond what anyone has experienced who hasn't heard Dominance or Def4. This is not an incremental iteration of Defintion.

I''ll get more tapped into text tomorrow or Monday.

Phil

Definition 1.5 was a livelier speaker than Def2, and its tonal center of gravity was shifted toward the upper midrange compared to Def2. The downside of Def1.5 was the MDF structure and the "cabinet talk" resulting from it at high SPLs. With Def2, Zu dramatically reduced the cabinet talk of the Definition architecture, giving it even more useful dynamic range, but one of the costs of tuning out the glare in Def1.5 was the slightly overdamped sound of Def2 (only in comparison to the incredibly jumpy Def1.5). The supertweeter network was improved as well, to tune out some of the older speaker's false sparkle evident in the supertweeter's anomalies. Def2 went as high, but it just didn't have all the tickle that Def1.5 had, along with that speaker's very top end distortions.

Def4 resolves the difference completely. Def3 should mostly. All of the liveliness of Def1.5 is restored in Def4, and then some. And all of the discipline and accuracy of Def2 is retained, and then some. The speed and openness of the nano-FRDs coupled to the tonal illumination provided by the smoothly extended Radian supertweeter eliminates the dark-tilt evident in Def2.

Solid State amps on Def2 went a long way to lifting the trace darkness in its tone, as did objective tube amps with extended top ends and bursty dynamic traits, but now that character isn't just mitigated. It's gone from the Def4 design and should be very much reduced in Def3's Def2 roots as well, since the nano-drivers are significantly responsible for the change (not the Radian alone). Def2s upgraded with 2010 HO FRDs pretty much lost the Def2 dark tilt anyway, so consider the small Def2 "overcorrection" to be adjusted out regardless which upgrade path you take.

Phil

Some interesting assertions here:

>>SET amps are good for what they do but there are other amps that from top to bottom will out run them. <<

Bring me one.

There are a LOT of SET amp choices but they aren't all equally good. You don't have to go all the way to an Audio Note Ongaku. Until you specifically hear an Audion silver content Black Shadow (845 SET) or Golden Dream (300B PSET) monoblock pair on Defintion 4, you won't know whether anything allegedly SOTA can meet or exceed it. People who have heard this next to ARC REF seris, Dartzheel, Nagra, etc. who prefer the Audion aren't compromising for SET. So, sure, at any given point of time maybe there's something new that beats a stellar SET amp on a Zu crossoverless speaker. Could be. But no push-pull tube amp at any price has shown me ability to hide its crossover grunge. No SS amp at any price has shown the holistic tone of highly developed SET. But I'm open to the discovery.

>>I have found a huge upgrade in Footers by Equarack/Stillpoint Ultra under the Def2 that transforms the sound of the speaker.<<

Definitely easy to accept. Foundations are inflential on resonance management. The effects are specifically unpredictable dependent on other system, room and resting surface factors but it's certainly worth investigation to determine the right upgrade for your environment.

>>...but if you have the Def2 with the new Nano drivers and SOTA gear you just might have better tunes than the Def4 owners with lesser gear.<<

Look, I'm the last person to push people into premature upgrades or to encourage upgrades beyond an individual's ability to spend. Def2 by any measure remains an excellent speaker and plenty of people with more expensive but less capable speakers today would be thrilled with it, along with people who can suddenly buy Definition architecture on the used market at an accessible price.

But until you hear how large the improvements are in Def4 over Def2, the sentiment that Def2 with state-of-the-art gear and a nano-drivers upgrade will be "better" than Def4 with lesser gear, is uninformed conjecture. At some level of comparison, sure. But consider that I and others have noted that CDs are more listenable and enjoyable on Def4 than on Def2, despite Def4 being more revealing in every way, and you can see that the listenability quotient applies as well to modest amps, modest sources, modest cables, modest analog. The smooth extension and spatial openness of the supertweeter plus the surprisingly upgraded bass definition, discipline, room loading and clarity have profound effects on your perception of imaging, midrange performance and tonal engagement.

Somewhere in the mix of SOTA gear on Def2s vs more modest gear in Def4 the proposition might become tenable, and certainly in past Zu speakers I'd have agreed. The equalization in performance between fab gear in Def2 v. acceptable gear in Def4 isn't the slam-dunk given you'd imagine, IMO, which I illustrated to myself a couple of weeks ago. My Quad II push-pull amps designed in 1951 sound on my Def4s superior to my 4X the cost 845 silver content SET amps driving Def2s, but the same 845 SET amps on Def4s blow away all comers thus far and the Quads, good as they are, can't compete.

If you have Def2s and need to stick with them for the forseeable future, be confident you still have a genre-defining speaker that can satisfy you for years to come, especially with Zu's willingness to sell you nano drivers to install in them. Just don't listen to a Def4 until you're prepared to buy them. Or send your Def2s back to become Def3s, to get yourself halfwat way there.

Phil

Agear,

You wrote "Zus are not impervious to associated gear." That's certainly correct and if anything I wrote was inferred by others to mean otherwise, I certainly didn't intend it. I've lost count of all the cables types I've heard on my Zu systems over the past seven years I've owned Zu speakers, let alone all the cables I've ever heard. But I'll mention a few that bracket the discussion: JPS Aluminata, Audience, 47 Labs OTA, Kimber, Audioquest Everest, Zu Variel, Ibis, Event, Mission. For the moment, let's stick to speaker cables.

I'll also add that I have heard an ASR amp on Definition 2, and while I understand why that brand's amplification is well regarded, it's not an amp I consider musically convincing. It has a lower noise floor than top tier 845 SET amps, though my Audion amps aren't noisier enough that their noise floor is obscuring to the point of allowing the ASR to reveal anything I can't hear via the tube amps for that reason. The ASR is a "better microscope" than the 845, but not a better microscope than my Audion Golden Dream PSET with its high silver content, including in the OTs. Certainly it's possible that a given listener prefers something akin to the ASR amplification over what I listen to, and certainly the complementary or compensatory properties I would want from cable would be affected by the amp I listen to. When I want to hear cable contributions, I aurally dissect using the Golden Dream amps first.

In the compass points of cable in the examples I've mentioned above, there are several design approaches. JPS prioritizes noise elimination and shielding through brute force material density and mass. Audience emphasizes time domain. 47 Labs emphasizes coherence and speed. Kimber emphasizes RF rejection and magnetic behaviors. Audioquest strives for transparency. Zu seeks coherence and balance. Auditorium targets convincing tonality.

Some of these cable choices are mass-intensive. Others eschew mass every way they can. There's a long-running debate about the sonic benefits of very low mass connectors vs. metal-intensive termination. So in brief terms, JPS Aluminata is quiet and good at preserving and presenting dimension, but I don't have significant cable-induced noise, so everything is pretty quiet anyway. I did not find any collapse of dimensioning going from JPS to Zu Ibis, but I did find the JPS to be less dynamic, certainly smooth but not as fast as Ibis. More to the point, it wasn't as coherent and resolving as the 47 Labs OTA, which counterintuitively uses single-strand conductors. But I can understand how the JPS can be heard as fleshing out a leaner audio device chain. Of the cables I mentioned, the various Audioquests had no advantage over anything else, so set all AQ aside for this discussion. Auditorium 23 cables are the most reliably musical regardless of source material of this group. Kimber never makes a misstep but it doesn't equal the best of the group in tone, transparency, resolution or dimensioning. It's a safe choice. Audience is incisive and precise. Zu delivers total balance with the silver content cables matching anyone's resolution. In some significant properties of sheer musicality, I liked Auditorium and 47 Labs best, and both emphasize low mass, particularly at termination. I would take either over JPS. I came back to Zu Ibis (and I can equally endorse Event, which is actually more forgiving than Ibis) for its well-rounded ability to be exceptional on speed, bursty dynamics, tonal coherence and event coherence.

I've tried many more cables than this, including Cardas and Nordost, and I haven't even gotten into ICs and power cords. But there's another dimension to the discussion. How much money should be allocated to cables in a system, or how much is needed for the system to be musically convincing?

All of the speaker cables I mention above were quite good on Definitions, in varying ways. None made the system unpleasant to listen to. But with a cable as good as Ibis or Event, I can drive larger positive deltas in musical performance by upgrading elsewhere with the thousands of dollars not spent on cable if Zu, Auditorium and 47 Labs are chosen instead of JPS Aluminata or the upper line AQs, for example. And if you prefer the more moderate cost lines, then standing pat on cables to put money into other areas or just buy more music, or pursue another interest in life can be the better choice. I can spend $6000 on speaker cables, but I won't if the results aren't compelling. I haven't heard compelling from JPS, as an example. I've heard "good" that didn't win against alternatives. But someone else like Glory who may hear differently or whom has different criteria for being convinced of a system's musical thruthfulness might prioritize his resources differently.

But I repeat that with Def4 restoring the Speakon connector for B3 geometry pass-through to the amp, the benefits of leveraging that via a Zu cable are significant and not exactly matched by other good cables that can't continue B3 to the amp output terminals.

Phil

By getting short notes up sooner, there are many aspects of Def4 I haven't yet commented on. It's true that the sonic spray into the room is wider. For me, it was already excellent with Def1.5 compared to most floorstanding speakers, though less broad than with the better point-source standmount monitors. But I had very good off-axis response and soundstaging in my room with Def1.5, which marginally improved with Def2. Def4 is a larger improvement in the distribution of full-frequency sound and soundstaging over Def2 than Def2 yielded over Def1.5. This is a function of improvements to all three driver segments. The supertweeter upgrade easily obvious in this respect, but the stiffer/lighter FRD cones spread better as well, and the monocone sub-bass makes its contribution to more even room loading as well. But while Def4 delivers a big sound when appropriate, it doesn't impose a spatially big sound when the recording or performance doesn't warrant it. The soundspace scales up and down to the music appropriately, yet the room is pretty evenly loaded acoustically even at low volumes.

WIth respect to power requirements: Sean Casey said at the time that upgrading Def2 with the 2010 pre-nano HO FRDs made the speaker perform more like it has 104db/w/m efficiency. He didn't change the rating on the speaker, but said the power transfer improvement with the HO driver would nudge the speaker's apparent efficiency upward. He was right about the "apparent efficiency" part and that probably was enough to make some small amps that were only marginally sufficient before, acceptable to some people in some rooms. Certainly, Def4 has an apparent efficiency that sounds dynamically higher than Def2 in its original form. There are multiple contributors. First, the nano main drivers bring the known strength of the pre-nano HO drivers. The supertweeter does a better job of keeping up with the main drivers as volume rises without losing clarity. And the sub is both cleaner and more articulate for being one driver instead of four, but also the new Hypex-based sub-bass amp has more headroom and it's "faster." So the net result is that with the jumpiness of the Def1.5 restored and furthered without the cabinet talk, I think some people can be happy with a smaller amp than with Def2.

That said, I still do not think that a 2w 45SET amp is enough for optimum general use, and won't allow a Def4 owner to hear the full capabilities of the speaker. But if you really like true flea-power SET, you're more likely to be able to live within its limits on Def4 than on Def2. I think the Definition architecture, however, is optimally driven by 12w-30w SET tube amps or the very simplest push-pull tube amps, of which the prime example is the Quad II monoblock pair, or some of the 300B push-pull designs like Audion offers. Seven to ten watts 300B SET amps are quite serviceable IF it is a design that dispenses with the bass bloat common in ordinary 300B SET designs, but that's really borderline with respect to experiencing the dynamic life Definitions can deliver if your room isn't small, IMO. It's not that seven watts can't drive enough average SPL. You hear the difference in the ease with which dynamic spikes are handled by the available headroom.

Nothing about Def4 changes my view that the ideal amplifier for it is 20-30w 845-based SET or similar big glass triodes. Some 211 amps in the 15 - 20w range are quite good too. At the recent L.A. Zu house party, I heard the Melody 211 stereo integrated amp driving my Def4s, and it was strong, agile, articulate and beautiful.

However, for people who like the broad creamy torque of a really large solid state amp, I think Def4 is even more accommodating of their sonic signature. For solid state, the McIntosh quad-differential autoformer-output power amps are particularly synergistic with Definitions. Electrocompaniet amps work well with Defs too. Despite the efficiency of Zu speakers, their high power handling gives you latitude other HE speakers can't offer. Put a pair of McIntosh MC1.2kw or MC600s on a pair of Definitions, and you will understand what the sense of "unlimited power" into a crossoverless speaker can offer in terms of sheer dynamic ease. Not everyone is ready for or oriented to tubes. Counter-intuitive to expectations and similar to the effect I'm hearing with CDs, I fully expect that the Radian supertweeter will present the grain and sometimes hash in solid state amps less obtrusively than the older Definition supertweeter. But this also means that low power solid state amps like Pass Class A, First Watt and 47 Labs should sound more beautiful too, than they have in the past.

A reviewer who is getting Def4s dropped by last week to hear them on my SET amps and on Quad II, which is what he will be using. If you've read anything here I've written previously about Zu speakers, you know that I advocate going heavy amplifier quality with any Zu speaker, and have said in the past that Superfly powered by a great $10,000 amp will sound better than Definitions powered by the best $1,000 amp. Given the quality of some tube amps coming out of China and on the used market, that may be less true with Def4. New production Quad II monoblocks list for $3300 or thereabouts. THAT is a hell of a lovely sounding combination where the amplification is reasonably moderate, the design is simple and retubing costs are light. Quad IIs sound considerably more muscular into Def4 than Def2, in part because of the new speaker's 8 ohms nominal load against 6 ohms for the older version.

Overall, I think Def4 allows a wider range of amplifiers to put it in its sweet spot, but I still think the centerpoint for optimum match is high quality 845 or 211 SET, led by (in order) Audion, Sophia and with Melody coming on strong right on their heels.

Phil

Regarding the questions raised by Spiritofmusic:

The downfiring sub driver has several advantages, in no particular order: In Def4, the driver is bolted to a 1.5" thick machined aluminum plinth, plus it's a cast-basket 12" driver. Mounting the sub driver to an equally rigid rear panel would require a much larger slab of aluminum or alternate material to achieve the same management of the driver's motion energy on a more expansive panel. Additionally, by mounting the driver in the plinth, the opposite wall is small and stiff rather than tall and large, so cabinet resonance is more easily controlled. The cone motion can't rock the speaker cabinet, either. Then, consider that the soundwave is projected toward the floor, which is generally a stiffer, less resonant surface than is a wall behind the speaker, at least in American sheetrock-over-studs construction. And the downfiring sub can load the room radially and reflectively, instead of mostly reflectively in the case of the rear-firing sub array. And not least, the single 12" cone can speak with one voice rather than the inevitable blurring of detail that accompanies four drivers even if they are matched (my primary complaint with linesource speakers).

As for cable, I don't believe it's absolutely necessary to have a single-brand loom for your system. All cables bring specific characters and you may want to use them selectively to tune anomalies in specific areas of the system, but when you can find continuity within one line, that's good. My Druids system has early Druids that have been upgraded over the years to v4-08 status, but they are early enough to have the Speakon connector Zu originally fitted as standard, to preserver their B3 cable geometry all the way from the FRD to the amp terminals. Since those speakers also have the Cardas clamp for spades, I years ago listened to the comparison of Zu Ibis cables connected through the Cardas clamp and via Speakon. My Druids are internally cabled with Ibis. For me, the simple preservation of B3 all the way to the amp is audible and favorable, so I'm glad to see it brought back to Def4. Whether you chose the character of Mission or Event or older Ibis Zu speaker cables, I definitely advocate going with a Zu speaker cable via the Speakon for full B3 geometry.

That said, a friend or mine who had Def2s with HO drivers chose the excellent and really beautiful sounding Auditorium 23 speaker cables, which use low-mass bananas and are natural-fiber jacketed. I will hear his Def4s soon and will compare the Aud23 via adaptor, with Ibis B3 via Speakon and let you know the difference. Cables are the least urgent thing to get right.

Further, Zu cables have a common thread of neutrality running through them, regardless of grade, so there's no problem mixing Event and Mission, according to expense or choosing one over the other for portions of the system. My systems have Mission in specific places where that's the right interconnect for phono and getting three turntables with five tonearms and multiple transformers and phono stages in two systems wired up, Varial elsewhere, and Ibis to speakers. I even have some custom-made tonearm cables made from Cardas 33awg shielded wire in the mix. When listening, no one is looking to scrutinize the cable loom.

Phil

The Hovland combination is excellent by any measure. As I've written before, despite the high efficiency, Zu speakers, especially Definitions, make good use of moderate to high power. The main issue to consider is that at 125w/ch, you are running a push-pull tube amp. There's a subtle grunge in the push-pull crossover signal handoff that is absent in SET, and which isn't especially noticeable until you experience its absence. An even excellent push-pull tube amp sounds slightly blurred and congested to me, after years of listening to big-glass SET. On the other hand, push-pull tube amps usually have better bass control and sound (and measure as) more strictly linear, all other things being executed to an equal standard. What is surprising to many who hear it for the first time, is how an 845 SET amp rated for 25w can sound equally or sometimes more dynamic than a 100+w push-pull tube amplifier, on a bursty, revealing and efficient speaker like Definitions.

You have to experience at length SET amplification to understand how it fits your perception of convincing musical sound. A Zu speaker is the perfect speaker to explore this with, and there is perfect concept continuity in mating a single-ended tube amp with a crossoverless loudspeaker. Just don't do it with an old-school slow and sweet kind of SET. At the expense level you're already playing, you can afford a good, objective SET choice. There's no reason you can't mate your excellent Hovland preamp to a good SET amplifier, so no need to take depreciation loss on two pieces if you decide to try the SET power amp route.

The Berning OTL option is also highly credible musically and convincing. Going transformerless but retaining the push-pull topology gives you some of the immediacy of SET but not quite the same thing. Berning has a truly clever OTL circuit that uses an RF carrier signal through a high frequency transofrmer to handle impedance matching without the audio-compromizing effects of an audio frequency transformer. The Berning gear, including the ZOTL preamp, have a specific brand sonic character, which is fast, dynamic and highly transparent. Some people hear it as accurate, others as a little sterile and lacking full tonal body. It's undeniably good. But so is your preamp mated to a suitable SET amp, which if selected well will give you a more holistic, toneful presentation with lots of body. It costs more to get the speed and sheer openness of the Berning in an SET design that delivers the full holistic sound that topology is capable of. Choices.

I think in many respects, the Berning sound can also be closely acquired in solid state in the form of Lavardin.

Phil

My Definition 4s are painted in a high-gloss 2011/12 Cadillac color, Opulent Blue Metallic, with the exposed aluminum parts natural. My Druids are gloss Ferrari red. My first Definition 1.5s were gloss Maserati Blue Nettuno (this became a standard Zu color after I had the first pair built in that finish). My Def2s were high gloss Ferrari red. I use my speakers for 2 ch music and incorporate a 60" display, so for movies the systems are HT 2.0. I don't find the gloss finishes distracting for movie viewing, but then again I manage to ignore incandescent 845 tubes when watching movies so any reflections off the speakers' finish is barely noticeable by comparison. Day to day maintenance is only needed if you have a household of folks who can't keep their hands off the speakers. The gloss finishes are automotive paints that are taking much less punishment than is incurred by a car out in the weather and sun. A little Mequiar's or Mother's instant clean and shine, with a clean microfiber cloth makes quick work of it. But no question the matte finishes require even less attantion.

There are a couple of things to keep in mind about the upper frequencies integration on Def4. First, you're hearing the main full range drivers up to about 12kHz, compared to a two or three-way speaker where the tweeter is crossing in anywhere from 2.5kHz - 4kHz. So most of what you perceive as high frequency performance is determined by the FRD. The new nano drivers are lighter, stronger, faster and therefore more articulate, energetic and refined than the Def2 pre-HO drivers. The spesaker's horizontal spray is also wider than before and most of the Swiss cheese effects in the Def2 soundstage are filled in. That includes the top sparkle frequencies where the Radian plays. Compared to the Def2 FRD/supertweeter hand-off, which was very good at the time of introduction and nothing to be ashamed of today, the Def4 same interface is seamless spatially, tonally and in transient character, and instead of the FRD outpacing the supertweeter as in Def2, in this case if there's preference in sheer beauty at the hand-off, it's in favor of the Radian. This is a lovely tweeter used in supertweeter application here, far better than the ribbons that annoy me, and vastly more listenable than the various and horrid metal and diamond tweeters used in some of high-end's mega-brands. The Radian uses an aluminum dome but with a mylar surround, which avoids the peakiness of most metal dome tweeters. It's not just a claim -- you can hear its extended and smooth neutrality, with dispersion more closely matched to the new FRD than in Def2.

Sidebar: 35 years ago, the Advent Loudspeaker was a great basis for building a highly credible high end system, in a market with much less choice, especially if you had the space for the Double Advent system Absolute Sound helped to popularize. That speaker produced very little worth hearing above 13kHz in a simple 2-way configuration, and spec'd out to perhaps 18kHz. At that time, Jon Dahlquist included a piezo supertweeter on his DQ10, which was flat out to 25kHz, but it beamed like a lighthouse. People did all sorts of things to improve it: wool diffusers over the piezo; replace it with a ribbon tweeter; remove it. Some people just said "....I'll keep my Advents" because they had a rightness to them without the distraction of DQ10's beaming supertweeter.

Well, listen to a Def4, or a Def2 for that matter and have two people handy to put their palms over the supertweeters while you play music. You're hearing nearly the top end of an Advent loudspeaker from the FRD's upper limit. Most of the character of the top end is determined by what you're hearing there. What any Definition's supertweeter adds is harmonic completion, further spatial cues and the subtleties of dfferentiation in expression via instrument materials, playing techniques, vocal inflection and tone. None of the Definitions added this with any ice-pick elements. The cabinet on Def1.5 was a bigger contributor to glare at high volumes than was the supertweeter. In Def2, the top end smoothed out some, but if you needed proof how much more influential the FRD is, you only had to upgrade your Def2s to the 2010 HO drivers. That put the supertweeter's relative contribution in perspective. In Def4 the Radian is a mister instead of a hose with a nozzle. But it's the new nano FRD that sets the stage for you to appreciate the Radian's deftness, dexterity and refinement.

Phil

The Berning 30/30w ZOTL amp has a push-pull output topology, using two of the 33JV6 tubes per channel. They are not, as I understand the circuit, wired PSET. It nevertheless is a clear and highly resolving amp.

Regarding the question of TVC: I headed down the TVC route in lieu of an active preamp about five years ago after I sold my crossover-based speakers and migrated both my systems to Zu. At the time I got the Django TVC assembled by DIYhifisupply, in the S&B TX-102 transformers option, with all internal wiring in silver/teflon. Shortly after that, the US importer shom I've known for over 30 years, was in California and stopped by with his first Music First sample and we compared them. Music First, the integrated products arm of S&B, calimed then that their own version of the TX-102 was in some unexplained way premium to the version they were then selling to other TVC makers, and as I understand it today, a Music First product is the only way a hifi consumer can buy a TX-102 based TVC new.

Regardless, the S&B xformers were and are among the best, and TX-102s including in Bent Audio, DIYhififsupply and other vendors' products were unconditionally excellent. The Music First TVC (what is now their "Classic") was very marginally, just perceptibly more resolving than the Django. It was a very small difference. And some of it could have been due to the Django's steel chassis against the Music First's aluminum. Switchgear, internal wiring and workmanship were fully competitive between the two, despite the considerable price difference (UK-made Music First more expensive).

At the time I had a variety of amplifiers and four active preamps on hand for comparison, three tube-based, and one the Audiopax solid state preamp on loan.

I liked the TVC, and still have the Django as my spare preamp. But it did not win out over my Audion Premier, nor my Klimo Merlino Gold, nor a Melody P1688 I was evaluating at the time. It did win out over my nearly 40 years old Stax SRA-3s tube preamp/headphone amp. I'll say more specifically that the TVCs -- neither of them -- were preferred to the active preamps with my Audion amps, which was interesting because of all the amps I had on hand at the time, the Audions had the highest input sensitivity, so even the +6db gain available wasn't needed.

The TVC did yield several sonic advantages driving Audiopax 88 tube monoblocks, and a pair of Quad IIs. Unfortunately, the input sensitivity on the Audiopax was very low, so the TVC couldn't drive them to full power with normal sources. At the time, to live with the TVC and the Audiopaxes for an extended period and drive them to full dynamic range with a TVC, I had a set of interstage xformers made from S&B TX103 step-ups, so that I could add another 6db of gain. Of course I had to be precise about impedance matching, but it worked with the Audiopaxes. On the Quad II, which have input sensitivity of 1.4v, I did very much like the refined presentation of the Django and Music First, and it has seemed to work well when anyone has brought a solid state amp to listen to.

So, on TVCs, I say your sound quality experiences will vary by power amplifiers. Into Audion Black Shadows and Audion Golden Dreams, the TVC sound is inferior to my tube-circuit active preamps, though I wish it were otherwise because the isolation and lack of an additional power supply definitely makes it easier to chase more noise out of an SET-based system.

Now, Spiritofmusic, on to your volume control range question. I get asked about this alot, so it bears explanation.

Your usable volume control range is not very much affected by the output power of your amplifier. Yes, with two power amps of same input sensitivity, the more powerful amp will deliver somewhat more power at a given volume control level. What you really need to pay attention to is the gain relationship between the preamp and power amp, and/or the input sensitivity of the power amp relative to the preamp's gain and therefore output.

For example: My Audion tube amps have input sensitivity of 0.7v, meaning a signal of 7/10ths of a volt will drive them to full power. Compare this to American amps that generally have an input sensitivity in the 1.5v - 2.0v range. You can see that, depending on the contour of a preamp's volume control and your sources, that generally if I use a power amp with 2.0v input sensitivity, I would get much more usable rotational range on my preamp's volume control. In fact I hint at this scenario in the discussion above. With a disc player having the standard 2v output, connected to a 0db gain TVC where all you can do is attenuate, I could not drive the Audiopax 88 amps to full power even with the TVC volume control turned all the way up, because the Audiopax's input sensitivity was greater than 2v. In a market where most power amps have 24 - 32 db of gain, the Audiopax 88 has only 18 db gain. On the other hand, the TVC set for 0db gain could easily drive the 0.7v input sensitivity Audion amps to full power with the attenuated output of a 2v out disc player.

So what to do when you use an active preamp? This is where input level control on power amps are helpful, because most gear has too much total gain in the chain. Right now, two of my three active preamps are fairly high gain -- the Klimo is 20db and the Melody 101 has 23 and 15 db options. But they each sound great with the Audions. The advantage is, my preamps are quieter than are my SET power amps (common for SET). So I can prioritize the gain in my quiet preamps over the gain in my noisier power amps by running the input level controls turned very low, effectively raising the input sensitivity by "throwing away gain" at the input level pot. This way, I get more usable rotation in my preamp volume control, and lower the system noise floor by reducing SET noise. It's not an amp power issue. I could put in an pair of 1200w McIntosh monoblocks with ~2v input sensitivity and have more volume control range than I'd have if my Audion amps didn't have input level controls, though there could be bigger consequences if the volume control were set too high. The point is, regardless of the power amp, you can choose a preamp/power amp combination that molds the gain relationship between pre/pwr to your operating advantage.

If the gain relationship or output/input sensitivity are not mated well, you won't get more useful rotational range from your volume control with a lower powered amp, but you might push the amp into clipping sooner. Make sense to you?

So if you want more usable range out of your preamp volume control with a given power amp, you either have to choose a preamp option with less gain or need a way to throw away excess gain via input level controls or find lower-output sources to eliminate the problem. A TVC gives you a 0db gain option or at most +6db optional, to reduce system gain, so if it in fact sounds as good or better than a higher gain active preamp, you will get what you're seeking irrespective of the power amp's output.

Phil

It's always helpful to have more of your volume control's range be useful and accessible than less, if all other things are equal. But would you be happy with a preamp you like less just to get more useful range from your preamp's volume control? Unless the useful rotational range is very small, probably the answer is no. You have two feasible choices if you like your power amp:

1/ Get a lower-gain preamp if you can find one you like as much;

2/ or more feasibly, get a pair of Rothwell RCA inline attenuators (review: http://www.enjoythemusic.com/magazine/equipment/0803/rothwell.htm) These can be placed in-line between your preamp and power amp, to scrub off 10db of gain before the audio signal hits the power amp inputs. If you look around, you can also find similar attenuators at 12db and 15db reduction. Simple, effective, cheap and you get more useable twist in your volume control. Don't obsess about having another resistor in your signal chain.

You could also get a TVC from Music First (expensive) or DIYhifisupply.com (affordable), for attenuation without gain.

I do hear the Berning as tonally leaner (a little too lean) than the Audion Black Shadow 845 SET. Audion electronics are uniquely fast among tube gear but fully fleshed tonally, so I don't agree that the Berning has more apparent speed than the Audion. The Berning sounds "faster" than the majority of SET amps outside of Audion particularly, and some Sophia. I have to extrapolate that Melody qualifies too. Others might. Audion's 2a3 and 300B amps are also impressive like the two top line amps that have silver content, for their quickness, so it's not just a top-line exlusive for them.

You can tune the Audion 845 SET nicely to preferences for warmth and tone or objectivity, via the 845 tube selection. The 845A, B, C, T, KR Audio, and NOS RCA/United/GE tubes lend the amp different voicings. With the Berning, your locked.

As for the Def4 cab structure vs. Def2: I haven't yet seen a drawing of the interior of 4, to see the actual strucure improvements beyond the obvious, but the obvious things are very significant. First, the speaker no longer has 4 ten inch holes cut out of its rear panel, where Def2 had 4 sub drivers. That by itself strengthens the tower box. Internal damping has been upgraded and I believe there is more corner and junction bracing. But the other obvious change is the speaker tower's foundation. The stronger box no longer compromised by cut-outs in the back panel is now firmly bolted to a 1-1/2" thick machined aluminum plinth that is vented for sound to escape and serves as mounting for the 12" downfiring sub. It's a robust, very stiff physical foundation for the more rigid box to rest upon.

I surmise the front panel is now marginally stiffer in addition to being damped by the considerable mass mounted to it. The baffle should be a little stronger in the upper half of the cabinet because the size of the Radian supertweeter forces the FRDs to be mounted further apart than on prior Definitions, reducing how much structural mass is lost in a concentrated area on Def 1 & 2 where the FRDs slightly overlap the supertweeter cut. But the big progress on reducing cabinet talk was between Def 1.5 >> Def2, with the upgrade to 15 ply voidless birch from MDF. That difference for intrusive cabinet resonances was dramatic.

Phil

It's more important to preserved Zu's B3 all the way to the amp than it is to futz with alternate cables, for getting the most out of Def4. This is the thing that All Def2 owners as well as Zu owners who have owned only their speakers during the "B3 Speakon interruption" -- you don't know what was left untapped when B3 was taken away. Even on the less resolving Druid, this is apparent if you have an early pair incorporating the Speakon interface, and upgraded over time to v4 status. You can clearly hear gains from exotic and even inappropriately expensive speaker cables, but when I then run B3 all the way from driver back to the amp outputs, rightness sets in.

So anyone enamored of cable differences and wanting to spend money on that path, knock yourself out. Cables do sound different, though landing on "better" is a crapshoot. Most are not improvements, occasionally one may be. The best non-Zu speaker cable I've heard so far is the Auditorium 23.

In ICs, if you're getting a flat 2D sound because you've substituted Verial for Teo, something else is likely wrong or there's something about the parametric qualities of the other cable that your listening mind interprets as dimensional. If the latter is the case, fine -- no one can argue with that. But it's far from generalizable that Zu Mission or Event ICs or speaker cables (or the older Verial/Ibis) are not capable of conveying the depth dimension information.

Still, cables are the least urgent thing to get right of all the variables you can pay attention to, but any given individual might prioritize a cable change benefit they hear, ahead of something else that to others makes a larger difference. This pursuit offers more ways to spend your money than most people have money, so if cables are your drug, go with it.

However, one of the best benefits of Zu speakers in all their architectural variants is their ability to be adapted widely and to yield excellent and convincing music fidelity with much less than state-of-the-art gear, and with fairly casual set-up. In fact this is elemental to the Zu brand. They want you to obsess less. They want to deliver exceptional value so you can spend less money on gear and more on music. They want you to be able to leverage ultra-fi gear but not mandate it you must spring for it. Just as Omen Def or Superfly can clearly leverage the benefits of associated amps, preamps and sources far above their price, Def4 can deliver its prodigious sonic presence when lashed to modest associated gear and still sound beautiful. My *advice* for how someone allocates their resources across gear categories will vary according to a buyer's goals, and it usually won't be to mate Defs with a cheap amp, but there are exceptions.

Additionally, while Zu does nothing to prevent the typical audiophile obsessions, they don't encourage them either. Like me, if they ran the world, their speakers wouldn't be hidden in dedicated listening rooms and man-caves -- they'd be out in the living areas of the houses of their owners, to be heard and seen in everyday living. So while a portion of the market buys Zu and installs their speakers and cables in systems located in dedicated audiophile rooms, Sean designs for the buyer who will install them in a living room where there's just one logical place for speakers, from a utility perspective for the way the room is used, and that setup is going to sound good too. Level 'em; get the toe-in right; you're good. In the true-fidelity speakers market, Zu is the "PnP" -- in speaker terms the Plop and Play" -- solution that also happens to reward obsessives and tweakers who are inclined to nth degree optimization.

Phil

No doubt the Spatial Black Hole has its benefits, and I know it can mitigate acoustic anomalies in very troublesome rooms, which it sounds like you, Spirit, have had to cope with. That was a good suggestion Sean offered.

But before the wider audience begins to think this sort of thing is necessary -- yet another box -- two things are worth keeping in mind. First, in decades of listening to both live and recorded music, I've yet to hear any of it in an acoustically perfect room. And when I've heard a "perfect room" like an anechoic chamber, treated-to-the-hilt listening room, or an engineered recording studio, it didn't sound much like music the way it's actually experienced, though the sound might have been beguiling for reasons other than realism. On the other hand I've heard two rooms that were perfectly convincing for listening to music, and neither were free of anomalies, including audible nodes and standing waves.

The two best "rooms" I've ever heard were 1/ Symphony Hall in Boston. I had a share of season tickets for 10 years when I lived there. It ain't perfect, but it's exceedingly natural, involving and satisfying to hear music performed there. The second "musically perfect" room I've heard was a family room on the first floor of a large Victorian house on the shores of Spy Pond in Arlington, Massachusetts. It wasn't a house I lived in. It happened to be dimensioned to nearly the same proportions as Symphony Hall. Otherwise it was just an untreated family room with normal furnishings, and a combination of large glass windows on two walls, a large fireplace on one long wall, and a shortwall of in-build bookshelves and cabinetry. The thing about that room was "any* combination of gear sounded not merely good but sensational in it. A receiver with a pair of $400 speakers sounded like $30,000 worth of gear, regardless of audible nodes. A friend owned the house and we made a project out of trying to make the room sound bad by installing the most objectionable hifi gear would could find. No avail. Throw it your worst -- that room made everything sound golden.

If you have a dedicated listening room and you want to hone it, have at it. Yup, the room is the big number in the equation of hi-fi. The Black Hole is a one-trick pony tackling a sliver of the problem. But then go out to listen to live music, and think about what you hear, how hearing it in compromised space isn't eliminating your enjoyment, and then go back and question whether your hifi optimization might be creating a more synthetic sound than you intended. Maybe, maybe not.

Agreed, it's absolutely true that sorting out the lowest octave's affects in your room has disproportionate benefits, and the Black Hole may be just the ticket if you have space for it or otherwise are willing to live with its presence. But if you don't have space or aren't willing to accommodate it for whatever reason, and you upgrade to Def4, you will find that the newer speaker excites the room much less, more evenly loads the room with its bass output, and generally reduces unfavorable room/speaker interaction. My moderate bass piling at high SPLs with Def2 is tamed and virtually eliminated with Def4.

The sub-bass user controls are not so simple as Def2's single level control but not so bewilderingly interactive as to cause endless twiddling. The tunability is logical and manageable, IMO. The sub driver is pretty stiff when new, so Sean gave me notice it will take some time to play in. Whereas Def2's level control offered equal gain boost and cut, with most people on setup starting with the sub level control at its midpoint -- 12 o'clock -- and then backing off a bit to perhaps 11 o'clock or boosting a bit to perhaps 1 o'clock, the expectation with Def4 is that cut is the more likely scenario, so in most rooms taking in brand new Def4s, you'll start out with the level control at 9 or 10 and back it off as the driver plays in and becomes more efficient. So I'm still at that beginning stage for level and it's spot-on. The low pass filter hinge frequency is set at 45Hz, the PEQ at 31Hz, and phase is set at 0 shift. I have no complaints but I expect to tweak these settings as the 12" driver plays in and limbers up.

Despite Def4's truly full range, I have the fewest resonance anomalies of any speaker I've heard in the room, and that includes well above the bass range too. So whatever problems you might have now with Def2 are going to be mitigated by Def4, *possibly* to the point of irrelevance.

Last, I dug further in the cabinet differences between Def2 and Def4. The front baffle is immensely stronger on Def4 than Def2, both because the further-apart spacing of the FRDs leaves more material in place at the juncture of three drivers, and (more important) the large compression tweeter and its lens form a stressed, compressing, rigid member that seriously boosts the rigidity of the front baffle at what would normally be its weakest area in an FRD-T-FRD arrangement. This is a major factor in further reducing front baffle talk from the levels reached in Def2 compared to Def1.5. Then, what you can't see is that to further drain the FRD's frame-radiated energy away from the baffle into the interior of the superstructure, each FRD's isolation chamber has an interior front-to-rear taper formed by interior side plates that are cleated into the front/side panels' mitre join, and angled inward by 15 degrees, then fastened into the rear panel. This nearly eliminates side panel talk highly evident in Def1.5 and much attenuated in Def2, plus drains the FRD energy into the rest of the cabinet where it is then steeply damped by the rigid aluminum plinth that bears the rest of the mass of the speaker.

Phil

Spirit,

You're right, the Black Hole is effective if the problem you have is the one it solves. Since you already own one, you conclude it's still valuable to your system when you move to Def4. And at $1250 it is an affordable antidote to a vexing sound problem in some rooms.

Gloss finishes on Zu speakers come at a premium, so the maximum performance per dollar point is obtained with one of the stock matte finishes. If you have a rambunctious family, the matte finishes will be more maintainable. If your environment is serene, the gloss finishes seriously raise the perceived value of the speakers. You might look into ebay and Audiogon history for some data mining to see if there are patterns in value retention different for matte or gloss. I don't know. I have a 60" final gen Pioneer Elite Kuro between my Defs in gloss and distractions during movie watching aren't a problem for us. I can't say with a larger image cast by a projector. But it you are wary of visual distractions from gloss reflections, consider getting your hardware anodized black. Silver FRD rings and the big supertweeter lens are more noticeable than reflections, in HT. IMO, among the mattes, Cosmic Carbon looks more suited to the value of the speaker than absolute flat black, in a domestic setting. But if HT is your prime concern, matte black with black metal hardware, will vanish visually in the dark.

Phil

agear,

Migrating from Audionote to Atmasphere to Tenor to ASR isn't a direction I'd take, and I've heard all of it. So I don't know how anyone would judge that or any other system as " the most musically convincing system to date." Well anyway not for me.

I did listen to ASR in my system. Even had a chance to buy it at half price. It didn't earn a spot, simple as that. If someone asks my advice ASR isn't going to be on a short list from me, but if someone else likes it, it's their call. I'm unswayed.

Phil

Agear,

A system is always holistic, else it's not a system. I don't think anyone -- and certainly I don't -- changes or adds compenents without adjusting the context.

When I listened to ASR in my system, I used all-copper cables first; reverted to silver-content for reference, but I had no expectation that silver would be the right context for an ASR amp. I listened with eight different phono cartridges on three turntables with five tonearms. And I listened to a variety of digital sources. But none of that mitigated the basic character of the ASR, which was undesirable to me.

The interactions that affect perception of ss gear aren't any more numerous nor fewer than those that affect perception of tube gear. Glory chose an amplification migration that I'd find unsuitable or more to the point, drifting *away* from convincing music presentation. I'll also note that every step along the way Glory contended in these forums that each amp was his destination, only to become further dissatisfied. If that happens with the ASR, what then? The trial and restlessness is often the indicator that the path is wrong. But if Glory is happy with his ASR, his cable choices and his Zu based system overall, I have no quarrel with that. It's his to enjoy on terms he sets for himself.

Phil

Glory,

>>Musical to you may not be musical to me but there is no way with the system you have built around the Def4 you can get better results than I have with my Def2.<<

You're welcome to that opinion. If you have a Def2 system, it's going to be pretty good even with the gear you've chosen. I'll only say I'd rather have listened to my own Def2 system, and more so still with the further upgrade to Def4.

>>Moral of the story is one must build, from the wall out, with SOTA gear to hear the Def speakers at their best. Having so so gear on a Def4 will not make it sound better than a Def2 with Nano drivers that has from the wall out HE gear.<<

I suppose that's the "moral" to *your* story. Who agrees on what's state-of-the-art? And what's the correlation to cost? And then what's the correlation to convincing musial realism in domestic reproduction? For as long as I've been involved in this interest, I've found the three quite weakly correlated, no less so today. I'll say that over 90% of all sound represented as "high-end" to me has instead impressed me as musically and aurally dysfunctional. Have you heard Def4? I'm guessing not. There are *many* combinations of gear absolutists won't consider "SoTA" that with Def4 will produce greater musical realism than Def2 -- even with HO or nano drivers -- such are the advances in total system performance. This is the paradoz of Def4: it is more revealing, more transparent, more dynamic and yet even mediocre CDs and LPs sound better in every respect than on Def2. You only hear in contrast how much Def2 you hear with that speaker in a system, compared to the marked and further neutrality of Def4. I think you will grasp this when you eventually upgrade. Until then, you're selling conjecture.

Also, a prior post hasn't made it to daylight. I mention in it that it's been years since I've used an NAD M55. In any case I make all my serious judgments from analog.

Anyway, we disagree. I have my path; you have yours.

Phil

Spirit,

I answered this question in a previous post. The five sub controls are interactive primarily insofar as the outcomes of anyone one control's settings acoustically may (likely will) influence your preferences on some of the others. If you change the hinge frequency, you may want or need some adjustment to the PEQ or the level, or both, for example. The phase setting may be more benign to other preferences but even that can influence level, PEQ and hinge preferences. What I wrote in my prior answer was that I do not see the five tuning options as being unnecessary complicated nor preventative of finding appropriate bass performance reasonably quickly. The new control options are not so simple as having only one level knob, but are far less tweak-inducing than a full spectrum parametric EQ and X-over combination. I think Def4 is pretty easy to dial in, and the controls are sufficiently intuitive to be usable by both experienced and novice owners. The primary enabling or inhibiting factor is the user's awareness of what to listen for, or whether they have either an intuitive or finely-honed sense of what sounds "right." Unless, that is, you're measuring, have the gear, and understand what's actionable in the resulting analysis. Not to mention, how obsessive are you -- do you know when to quit?

Phil

It's hard to argue against any Audion amp to be used with Zu. The Silver Night 300B monoblock power amps are available either as PSET or P-P. 18/18w is fine with Def4. The issue is the bottom end. Look, I have the Golden Dream PSET 300B Audion top-line monoblocks. They are a big step up from Silver Night, with more controlled bass and still, the 845 Black Shadow surpass the Golden Dream on deep bass performance -- and that's after a recap mod to further improve Golden Dream bottom end discipline over stock.

Take your pick based on what's important to you: The 300B PSET amps will have greater ultimate resolution and tone density. The 845 SET amps will have greater drive, more defined and punchy deep bass, and mids/highs will be still meaty, toneful and strong. If you were asking about Superfly, limted to a bottom response of about 30 Hz, I'd say go for the 300B over 845 option. But for Defs, the 845 bottom will underpin a more complete dynamic realism and give you nearly all the midrange magic of 300B SET, with more shove in tonal events and indisputably better dynamic life. If you like maximum presentation of delicate information and don't mind some ripeness in your bass, then by all means choose the 300B PSET. A compromise would be to get more like the 845 bottom end in the 300B push-pull version of Silver Night, but that's at some expense to the holism of SET.

I sometimes use my outstanding Golden Dream pair on my Defs, but by and large, they do tone-drenched duty on my Druids and the 845s put in ceaseless duty pouring watts into Definitions. But if you can, listen to Silver Night 300B vs. Black Shadow, and tell me what you embrace?

I've heard unmistakable advantages to TVCs in place of active preamps on a variety of power amplifiers. On paper, the advantages should be uniform, but in practice they are not. All I can tell you is that I've tried a few high-grade TVCs into Audion power amps. Not even one of those combinations tied with or bested the sound I got from the same Audion amps fed by my extant tube preamps. The combination of TVC + Audion power amp certainly did not sound in any way poor, but compared to other TVC + amp combinations where the resulting sound was a clear improvement, the Audion + TVC combinations failed to satisfy, even sometimes setting sound quality backwards a bit compared to pairing with a fine active tube pre. It's possible that if you rewire the inputs on the Audion power amps to bypass the input potentiometers that the TVC might become preferrable, but then the volume control range and precision may not be adequate, given the high input sensitivity.

You should try it yourself and see which combination you prefer -- no harm will come from disagreeing with me. But if you are asking for my recommendation, my answer is to find best satisfaction, on balance, via Black Shadow over Silver Night, and active tube pre over TVC with Audion power amps, *on Zu Definitions.* If you decide the 300B amp better matches the attributes you value most but you find bass performance the only area of doubt, you can either have a technician perform a recap of the power supplies to improve bass, sacrifice some single-ended tonality in favor of push-pull control, or live with some bass bloat and do your best to tune it out of the Def4 sub via the subs' performance tuning controls. Regardless, these are differences of degree. Any of the Audion amps will be exceptional, and whether to TVC or not to TVC is up to you.

Phil

Marc,

In most rooms, when you get new Def4s, you should start by running the sub Volume control at max (10) and as the driver breaks in, you'll likely back off from that over time. If 10 is too much just dial in what's right. Then starting at about 48Hz for the hinge frequency on the low-pass filter, experiment. You'll find the right handoff in the 38Hz - 50Hz range, and again break-in of the sub driver may nudge a change.

As with Volume, start with the PEQ Gain all the way up and adjust subsequently. For the PEQ Frequency, Zu's suggestion was to start at 31 and work around that centerpoint for the right balance. I agree with that so far, at least nothing about my room or system argues for finding balance around the extremes. Start with 0 Phase shift. You should twirl this to hear its effect and return to 0, listen, and tune from there if you hear advantage. I'd move from 0 conservatively. Doing initial setup through this order of priority, one at a time, will give you a feel for the acoustic interactivity of the controls.

An analyzer can't hurt -- even some of the iPhone analyzer apps can be very helpful if you are not confident of your ability to get it right by ear alone.

My general preference is to put nothing between the pre and power amplification. I have a *very* high bar for processors of any type to get over to justify making an exception. I haven't heard the QOL nor the X-DREI, though know about both. From people who have heard the QOL whom I know, reaction was that it seems successful in restoring tonal completeness to solid state amps, and that it is much less contributive to a high quality tubes sytem. That suggests that something like the ASR, which has come up in this thread, might benefit from QOL, since that amp sounds tonally incomplete to me irrespective of its resolution. That's not-uncommon problem in solid state still, even as silicon amplification has conclusively evolved past its once-common characteristic harshness. In any case, over decades of involvement in this pursuit, one thing is consistent -- processors generally don't last long in systems, so I'm open to hearing and being persuaded, but I am intrinsically skeptical about lasting value. I expect to hear a QOL for the first time in a few weeks.

As for X-DREI, it's intriguing but if you look at their own data, you can see that the processor alters every category of waveform fed into it. So is it a fidelity device or just euphonic? I don't know until I hear it but it has to be transformative to win consideration from me. In both cases you can buy/try/return so if you're game, go for it.

Last, regarding these two devices and anything else like them: Both companies deliberately obscure explanation of how they work. Both do it under pretext of protecting their IP. Well, in the tech game, your basic obligation is to innovate for value and then run faster than everyone who might chase you. As long as both companies refuse to explain what their devices do to the signal and how they do it, demand will be truncated and their impact on the market will be limited. It's their choice. At least with the Stein Harmonizer H2, the developer says flatly that his device relaxes the acoustic "stiffness" of air. He doesn't explain how, but he's not putting his device in my signal path either. If you're passing my system's signal, tell me exactly what you're doing with/to it.

Phil

Glory,

I first heard Tenor amps, pre-Zu and then when I first got Def1.5s, early in the last decade, both their 15w and 75w amps. I have a friend who cycles through high-end gear at whirlybird frequency, including the existing Tenor stereo amp. I haven't heard the $90k monoblocks on Definitions. He brings some of his gear to me because he hears attributes on crossoverless Definitions that he doesn't hear through his Magicos, which is how I heard the current stereo amp. Look, Tenor makes drop-dead gorgeous gear that sounds lovely in isolation.

Now, keep in mind, I have been an OTL advocate in the past. One of the longest continuous amplifier stints in my systems over the past 40 years was held by Futterman OTL monoblocks, hand-built by Julius, which I bought from him directly back in the late 70s. I used those amps for 12 years. So, believe me, when I've listend to Tenor and Atmasphere amps in my Zu-based systems, I *wanted* to like them, and they are certainly quite good in an isolated sense. Both are particularly notable for being "fast" amps that happen to use tubes.

But I have something that changes the context from evaluating Tenor and Atmasphere in isolation, and that is my Audion amplifiers. How expensive does an amp have to be to seem credible to your threshold for "expensive gear?" My Audion Black Shadows are $12,995 per pair and they are the not only the best 845 amps I've heard at *any* price by anyone, they are among the five best amps I've heard, period. But then I have something else: my Audion Golden Dream 300B PSET monoblocks. These amps cost almost $20,000/pr in the configuration I have and can be ordered in configurations up to $36,000/pr. Very few people have them and few here in the US have heard them. But these are the best overall amplifiers I've listened to regardless of price; and yes, used with a speaker with which their power is adequate, I prefer the Audions to Tenor and easily over Atmasphere. They are tonally more complete and musically convincing with Zu Definitions and more so now with Def4. I hear five and six figures amplification more than you probably suspect, and very little of it impresses me. The extreme cost high end in audio generally heads down a resolution vector detached from tonal authenticity, that is unrelated to the way we actually hear music if heard live. This is the central disease of hifi over the last 30 years. Audion's upper tier amplifiers are sonically swift, transparent, dimensionally convincing, dynamic and, best of all, tonally complete.

I don't doubt that you "hear huge sound differences" as you change out gear. Of course you do. The question is entirely whether those huge sound differences are enhancing of or deleterious to convincing musicality in playback. For me, and anyone taking my advice, you are takiing a path that meanders from musical realism *compared to some other options you could take* and which I have taken. But you're convinced of the musical authenticity of the gear you've assembled, so be happy. What does it matter what I think? Regardless, we are talking differences of degree at high cost compared to the gear decision most people have to make.

Generally I've seen very little correlation between most expensive and best, in hifi, so cost doesn't impress me. But best is certainly seldom cheap. We all just decide how much is appropriate. It's not a competition, Glory. Anyone who is attracted to what you describe in cost and sonic consequence, is free to follow. It affects me not at all. I've made no power amplification changes since 2005 in both my systems and I'm only now about to make one preamp change. I bet a lot of people here would like to find that stability in their hifi.

Phil

Marc,

You'll need to spend some time on that range of auditions. I missed mention in your earlier posts that your Hovland power amp is the SS Radia and not the EL34 push-pull amp. If you haven't spent serious time with a high-grade SET amp, it would be enough of an adjustment to evaluate one agasint a push-pull tube amps, but in this case you're making the comparison of SET v. a very good SS amp. So give yourself some time to assimilate the differences you'll be hearing, and process what's meaningful to you.

Some things are a one-way street. Since experimenting with SET and SEP amps some years back and settling on a very high grade instance of SET amplification, I am unlikely to ever own a push-pull tube amp again -- especially one of high power output as long as I'm using efficient Zu speakers. Once you've given up the tell-tale crossover grunge in a push-pull amps -- which isn't obvious or so bothersome until you jettison it in SET -- you tend not to want to go back to it but instead pursue better SET. One of the few push-pull tube amps still satisfying for me to listen to is the Quad II monoblock pair, in either restored vintage form or the current Asian reissue, and ther reason is the circuit is about the simplest available in that topology today. You don't mind what it doesn't have, and you appreciate what it does correctly. What you will get from SET at the level of implementation in Audion Golden Dream, Black Shadow and even Silver Night is speed and tonal completeness that you usually have to trade one to get the other at Audion's transparency.

The vast majority of solid state amps are push-pull, but some are Class A, and there are a few single-ended transistor amps, as Nelson Pass is issuing, that present some interesting competitive developments. Lavardin's work in curtailing "memory distortion" in silicon devices yields an unusually musical solid state amp. McIntosh autoformer-output and quad-differential solid state amps are good options for some systems. But none of these options so far, for me, matches the tonal completeness and holistic presentation integrity of very well designed and implemented SET. I'm certainly open to any of them satisfying me in the future.

This is a long way of saying that while the Hovland Radia is a great amp, it might have worked for me back when I was still using low efficiency 2-way or 3-way crossover speakers, but I am down a path I can't return from in terms of being satisfied by that sound again, given what I listen to now. Whether you agree or not will be learned in your auditions. I'll only add that whatever you hear in the Audion amps, can be improved through tube ugrades, but the fundamental amp characteristics are going to be fully present, stock. That said, I'll say the Tenor and Hovland sounds are closer and to me more "correct," than ASR.

The Berning ZOTL is a very clean tube amp, and as I mentioned in an earlier post, it handles event changes with speed and alactrity. It's a good amp. The ZH-230 is a push-pull design, so it has better bass discipline than most SET amps and sounds open and linear, like a wideband push-pull amps should. Good as it is, it sounds tonally incomplete to me -- favoring ultra-definition over holistic presentation. The Audion amps -- especially the silver-content ones -- have the speed but aren't underfed instrumental tone and "correct" human voice. On the other hand, the Berning will sound more like what you've been listening to in your audio past, but with more beauty. The Hovland Radia will have the events, "the consonants and the vowels", in music present but compared to the Audions will sound emotionally bleached. The intellect in music will be illuminated but heart will be more remote. Of all those amps, the only ones that get electric guitar tones truly, authentically right, are the Audions, and Zu speakers are ultra-competent at revealing this. And then once you grok that, you begin hearing the same authenticity in other strings, and in brass, and in voices. Tonally complete is how I think of it.

Buffers are antithetical to system simplicity, so I'm not interested. Get the impedance chain right in the gear you put together. If you buy Audion amps, you will have input level controls, and gain matching will be easy. You have no drive issues if you keep your excellent Hovland pre, or move to Audion. And with those amps, even the TVC will be fine, if that becomes your winning preference.

This is how I see your choices. Others may disagree.

Phil

I do use an Audion Premier preamp on one of my systems. It is an earlier generation, with full remote control (volume plus switching). The sound of Audion preamps is in the same class as their power amps. The Klimo is in one system as a consequence of once having had Audiopax 88 power amplifiers, for which Audion's preamps did not have enough gain to drive (the Audiopax having only 18 db of gain and unusually low input sensitivity, requiring a preamp of 20 - 25 db gain), and the Klimo brings similar qualities so there was no need to replace it when I replaced the Audiopax with Audion's Black Shadow.

My Black Shadow monoblocks don't consume enough power to be dynamically constrained by light power conditioning. When I had higher-power amplifiers in the past, I did run them straight from the wall but in this case there's no dynamic difference. It's a peculiarity of my present location that mild power conditioning lowers the noise floor a bit whithout dynamic penalty. In another power neighborhood my configuration might be different. I'll likely add balanced power for the power amps and when I do, I am sure I won't be using power conditioning with it.

But I'll make an earlier point again: Balance is my measure, and that includes balance between my interests. My systems are in a good state of equilibrium today. My next push is to prepare for adding hard disk playback by settling on DAC choices that also benefit optical disc playback.

Phil

>>I gather you've moved away from belt drive<<

This made me chuckle. Circa 1976 I owned at once a Linn Sondek, Luxman PD444 and a Transcriptor Glass Skeleton. I've been using the Luxman PD441 and 444 turntables for 36 years. In the meantime, Linn, Pink Triangle, VPI, Mission and several other belt drive turntables have come and gone. Along the way I found the Luxman direct drives could be significantly improved by replacing the stock spring/elastromer feet with brass cones on Aurios media bearings. At the time, the Luxman PD444 was the best sounding direct drive turntable of its era, better still than the Technics SP10 and SP25, and it has remained the table to beat in my systems. I have two PD444s with the footing upgrades. So me using direct drive is not a recent thing nor a "move away from belt drive." I used both drive technologies together in my systems over the years, but about ten years ago sold my last belt-drive turntable. I haven't heard anything belt-driven to persuade me to return, save possibly the top version of the VPI Classic.

If Luxman hadn't made the PD44X turntables, I'd probably have been using belt drive all these years. The design choices made for these tables were exceptional and in some respects resemble choice Harry Weisfeld arrived at for his Classic series about 35 years after the Luxmans were engineered. The Luxman PD444 weighs about 65 lbs because its plinth sandwiches a chipboard (better than MDF for resonance control) core between a heavy iron plate and an aluminum top sheet. The drive motor, custom built by Tokyo Electric, includes magnetic repulsion for a "load-free spindle" (really, load reduced bearing), phase-lock loop and a perimeter-mass platter to smooth out any residual "hunting." At a time when an armless Linn Sondek cost $350 in the US, the Luxman PD444 was $895.

The closest equivalent today is the Brinkmann Oasis, and if I were to replace my Luxmans today, that's what I'd buy.

Now, each drive technology sounds different. I did briefly own a Thorens TD124 in 1975. Less was investigated back then about plinthing idler drive turntables in domestic hifi, and idlers had fast lost respect for their problems. But remembering the energetic drive of that Thorens, a couple of years ago I bought a nearly NOS Garrard 401, had a birch-stack plinth made for it and topped it with a Thomas Schick tonearm to use with Ortofon SPU cartridges. That has proved a sufficiently entertaining alternative to the Luxmans that I am pretty sure I'll upgrade it with a slate, slate/wood or solid wood (blocks laminated) plinth. The Luxmans have the more precise, objective sound. The Garrard/Schick/SPU produces a big, robust, bursty sound less extractive of detail than the Luxman, but more imbued with sheer emotion.

I used the direct drive Luxman for 25 years before moving my systems to SET amps about ten years ago, and then to Zu + SET in 2005. So the "shift" between drive systems had different origins. Modern SET + Zu overcame a multi-decades dissatisfaction with hifi for me. The ability to at once be relieved of the incoherence, phase anomalies and dynamic choking of crossover-based speakers and enjoy the absence of crossover grunge in push-pull tube amps, get the tonal completeness and integrity of SET and wideband drivers, with modern sonic accuracy ended the futility intrinsic to high end audio as a pursuit, for me. It was a far bigger development than choosing turntable drive systems. Since placing Zu + Audion SET in my systems, a wider range of music has been made listenable and enjoyable. My patience for truly advancing upgrades is Zen-like. And I am entirely opportunity-focused about improvements rather than chasing irritations around the edges because the central topological problems in speakers and amps weren't solvable.

It's not that I am upgrading via DACs as much as I am going to expand by adding another source, and if I can get an upgrade to optical, terrific. We're clearly, in the waning years of Redbook CD, getting more options for good sound from that format than in all the years of the format's existence up to, say, 2009. So this is worth paying attention to.

When you're evaluating turntables/tonearms/cartridges, beware the many contemporary devices that succeed in making vinyl sound more like CD. Prioritize simplicity and quality of execution. And remember, you have to live with the device day-to-day, which can be different from 2 hours in a store.

Phil

Marc,

>>...as a direct drive advocate yourself, together with an ever increasing band of followers, do you feel that direct drive (or idler drive) if implemented correctly will always trump belt drive, or as belt drive advocates argue that it is a synergy of everything being well engineered, speed stability being important but not totally decisive over the whole package (materials, isolation, motor quality)?<<

Keep in mind, I am not specifically an advocate of direct drive. There were plenty of bad DD TTs made; frankly most did not sound very good. It was easier to make a reasonably good sounding belt drive inexpensively than it was to make a good sounding cheap DD TT. I settled on a particular DD TT that was exceedingly well implemented. Each drive technology has attributes and sonic character that can be right and musically persuasive, if the TT is designed and built well. The cliche' characterizations that belt drive sounds relaxed (but lazy), direct drive sounds energetic but brittle and idler drive sounds vivid and dynamic but is noisy and erratic have some truths in their origins, but instances of each violate the generalizations, as the aging Luxman PD444 refutes standard criticism of DD.

Today, you can spend anywhere from a few hundred dollars to the price of a house on a turntable. It's hard to recommend without knowing where in that cost continuum your appetite to spend lies. The top end of the market, like so much of high-end hifi, is unmoored from a sense of proportion. After all, the vinyl LP medium itself is not only quite flawed, but even now, specialty production of vinyl LPs yields *highly* variable quality. So is it worth having a $150,000 turntable? Is it worth building a turntable foundation into your house, anchored to bedrock via caissons -- rendering your turntable in part a stethescope on the planet? Only someone who is prepared to allocate resources at that level to spin a vinyl disc guaranteed to not be flat or perfectly concentric can say whether its worth the spend to them. A lot of the five and six figures machine shop exhibitionist turntables I've heard don't convince me, but then the Continuum Caliburn proves a lot of cash can be well spent on spinning and tracking a $20 disc.

TW, Walker, DaVinci, Kuzma, many others have highly credible turntables that are departures from the decades-old AR/Linn/Thorens suspended chassis belt drive architecture. You can't possibly hear all of them comparatively, nor own even a representative sample today. Again, I prefer to keep thing simple. If I were buying today to replace my Luxmans, my short list:

Brinkmann Oasis -- no need to look further for DD. It's as perfectly implemented as it gets.

47 Labs Koma w/ Tsurube tonearm -- counterrotating twin platter is a terrific idea and the belt drive system is taut, dynamic.

Acoustic Solid Wood Reference -- massive platter riding on plastic-lined bearing for intimate fitting, in a thick multi-plex wood plinth and driven by a precision outboard motor via monofilament.

VPI Classic 3, for reasons mentioned previously, though it loses points for forcing its unipivot tonearm upon the buyer.

EAR -- the magnetic drive is intriguing, and Tim DiParavicini has yet to design anything inferior.

Then you have to solve the problem of what to place your turntable on. I could add others, like the Opera Droplet LP5.0, Tritium, vintage Micro-Seiki, on and on. But these that I've listed are investments of reasonable proportion (in the realm of high end audio) that won't disappoint. You'll just have to listen to some representative contenders from each drive technology and decide what's convincing to you in the differences of degree between them.

I'm not in favor of vacuum hold down. I was involved in the final development and productization of the Souther Linear Arm 30 years ago so I have a special appreciation for linear tracking tonearms, but I don't prefer the relatively massive current implementations nor their complexity. And anyway when you can get something as pure, simple and well-made as the Schick 12" tonearm today, a Tri-Planar, a Graham, or Brinkmann's 10.5" or even a Rega RB1000, know when to quit.

So, no -- DD won't always trump belt drive. Idler can be beautifully implemented but it won't always prevail either. There are excellent examples of all the primary drive systems -- even magnetic. But unless you're willing to buy blind, knowing any of these are going to sound good, you'll just have to listen and find out what characteristics are most convincing to you. Nothing, at any price, is going to be perfect.

Phil

Charles,

I know about the Takatsuki 300B, but I haven't heard them. Construction details appear beyond reproach. I have Emission Labs, some older Vaic, KR Audio, Sophia mesh plates and some Chinese solid plate 300B tubes. When I got my Audion Golden Dream PSET monoblocks, the stock 300B tubes were Audion private label Chinese (appeared Shuguang) production. At the time, Audion's position was that the amps were optimized for readily-available mass production Chinese 300B tubes, so there was no need to buy high cost alternatives. I laughed about this at first, but several trials of higher-end tubes did not yield meaningful improvements, and in some case, more expensive tubes were setbacks. The Audion label Shuguang tubes were the most objective.

This changed after the amps' power supplies were recapped. Then, some of the higher end tubes that introduced colorations in the stock amps, instead sounded objective while their individual attributes still shone through. So, the Sophia mesh plate, which was previously euphonic and marred by its bass bloat, is now linear and has good bass discipline while its image-benefitting high frequency "spray" is still present. The KR Audio 300B, which was great for its fast, tight bass and punchy clarity, but not favored because of its "hardness" and glare, now sounds open, dimensional and defined without its former pugnacious aggression.

But thanks for the reminder, as it is my intent to seek and try the Takatsuki. I am not surprised you find it a clear upgrade from the Shuguang Treasure. I'm wondering how it will compare to the KR and Emission Labs in my Audions.

Phil

Agear,

The less said about Gary's choices of expression in the prior inconsequential imbroglio the better. But there is a difference in civility of discussion between me declining to endorse Gary's amplification and cable choices (which is what he seemed to want) and his langugage, tone and the shop-worn "Ford Focus" analogy. I did plainly write several times that I had no quarrel with him believing his choices were right for him, and that it shouldn't matter to him what I think. My entire reason for debating the point was to refute the idea that buying an exceptional speaker like Definition 4 mandates a subsequent massive investment in state-of-the-art gear to realize their potential. That's a pernicious notion, IMO, that I resist no matter the brands involved.

On the matter of a Zu owner who auditioned Audion gear on my advice: I don't know who you are referring to nor the circumstances of their audition. There are only two people I know of in the US who actually bought Audion Black Shadow 845 monoblocks specifically, for Zu speakers. In one case, the gentleman was unhappy with very well regarded solid state amps many times the price of the $12,995/pr Audions. He bought the amps blind, on my advice, and his response was "this is the best sound I've ever heard from an amplifier" (I have the email). He did not keep them. The reason is, he is highly sensitive to and intolerant of noise in electronics. He doesn't even like to hear relays on turn-on. I had warned him as part of my recommendation that the Audions would not be noisy in an obvious sense but they would not be as quiet as his solid state amps, and if this was going to be a problem, we should consider other options. He wanted to try, having never owned a tube amp, let alone SET. Others who heard his system found the noise level of the Audion amps to be inconsequential, but it was his system, not theirs. He's now embarked on a search to get "that same Audion sound with solid state silence." So far, he's still searching and I'm searching with him.

In the second case, the Black Shadows are firmly ensconced in a two-systems household and the qualities of those amps are fully recognized and appreciated, with both Zu and two other brands of speakers. I know of several others in Europe and Latin America who bought these amps after reading my experience with them, and all of those owners are happy. Black Shadows, particularly tubed well, are not "overly colored." They do have middling SET noise (less than most, a little more than the quietest (Sophhia)) and while I plainly say that most push-pull tube and solid state amps will have greater bass discipline and precision, the Audion 845 produces well-defined bass that is convincing and easily within the realm of high-end sound. Still, others may disagree or simply prefer something else, and that's OK with me.

Phil

>>Do you use power conditioning on your Def 4 plate amps as well as the front end electronics?<<

I simply power my Def4 subwoofer amps directly from the wall. I haven't heard any advantage to power conditioning there, and my balanced power transformer for the front end doesn't have the headroom to add them. When I get a higher-capacity balanced power isolation transformer for power amplification, I'll try the Def4 Hypex amps also powered balanced; perhaps that will prove better than directly from the wall.

Phil

Marc,

I haven't heard any one TT drive type make all others moot, in the way that SET + Zu has been transformative for me. And I know of no one who has directly compared everything credible. I have, btw, heard the Palmer but not comparatively. It's good. Whether, for instance, it's better than the Acoustic Solid Wood Reference which is also excellent, I can't say comparatively.

How people who have heard the Dobbins Beat would in direct comparison judge alternatives as different as the DD Brinkmann Oasis, the BD 47 Labs Koma and the EAR Disk Master with its no-contact drive system, would be interesting and, practically, anybody's guess. The difficulty of access for straight-up comparison points out the futility of seeking "best." In today's boutique world of TTs, you're buying flavors, not perfection. Have fun choosing!

Phil

>>Audion Black Shadows (though had a prob with the amp grounding---so were uncharacteristically noisy)<<

To update this: what we thought was a serious ground loop we didnt have the time or means to resolve was instead a failing bridge rectifier on one of the mono amp's filament circuit. Since repaired and quiet was restored. It was more than uncharcteristically noisy -- the hum was overwhelmingly intrusive. We'll be doing that demo again, this time against the like-minded Sophia.

Phil

My Druids are Ferrari red gloss, and so were my Def2s. Strong. It fits my home's scheme. My Def1.5s were Maserati Blue Nettuno, and my new Def4 are a Cadillac metallic blue. Nice counterpoint to the red system. I'll say this:

One of my cars is black. No more black cars. They look great clean, but they're perfectly clean for about 37 minutes after washing. Zu speakers in gloss black look splendid but show every fingerprint, dust spec & clearcoat scratch, just like a black car. And personally, I think Defs are too big to be a pure black object domestically.

Gloss red shows very little routine dust & prints. All colors are equally easy to clean & polish with automotive products. If red is too vivid, I think deep metallic blues look less severe than black and the color is more forgiving between cleanings. Alternately, a friend here in LA had a pair of Defs in a BMW metallic charcoal, and that was also elegant & forgiving compared to black.

But if black is your thing, consider choosing a black with light metalflake. It makes a black paint less glaring of faults.

Phil

Well, Gary, it was an entanglement. That's not perjorative; it's just descriptive. And isn't every disagreement in an interest like hifi a triviality? relative to the real problems of this world?

Well, for me it is. Don't take it personally, which has been my point.

Phil

>>The burning question is whether the Def 4s fit into this category? There is an inconsistent witness here. Telling people to drop 13K on a speaker and not to sweat the rest is a good sales pitch. I have no doubt they are excellent speakers.<<

This is a reasonable objection but it's not an accurate representation of my view. First, I am not telling anyone to drop $13K on a pair of loudspeakers unconditionally. Some people who already own Def2 should keep them. Some people who have a total spending ability only marginally above the price of Definition 4 should have a system built around Zu's Soul Superfly or Omen Def or some other speaker instead. But if any given individual appreciates Def4, can afford, and wishes to buy a pair, it's one of the speaker's strengths that more modestly-priced amplification and sources can successfully leverage the clarity and beauty of the speaker. As anyone who's read my various Zu-thread posts over the past several years knows, I advocate going heavy on emplifier quality with any Zu speaker, but I also hear many affordable integrated amps successfully used with Definitions, and more than a few high-end systems using the $995 Oppo BDP-95 universal disc player as the sole digital source. Prospective buyers should understand they can get very fine sound making one premium purchase with Def4, plus two moderate ones, if that's their choice.

>>Phil, it is not a pernicious gesture on Gary's part to suggest that you can maximize the 4s potential with different gear.<<

It's not "different" that I argue against. The pernicious notion is that Definitions can't be their best unless expensive "SOTA" gear is used with them, which Gary directly stated. People stay away from hifi in droves because of this elitism, and anyway it's wrong. This industry we buy from has many examples of spectacular cost and allegedly SOTA gear completely failing to deliver value or even good results at unreasonable cost. There is a further pattern of escalating cost gear only delivering another variant of coloration -- cables being a primary offender. Worse is the implied intolerance for the ideas of value and restraint. Glory's initial diatribe attacked the idea of building a balanced system of controlled budget, that might leave some of the speaker's potential hidden. Ignore our differences over ASR, for that was the sideshow. It's not unique to Glory. This attitude arises in many debates here and on other audiophile forums. His central theme was to denigrate balance and restraint in system building. I didn't agree that the choices I made result in lower fidelity but that wasn't elemental to the discussion. Glory was explicit: If you're not using a variety of more expensive gear with Definitions, in his analogy you're driving slowly in city traffic in a Ford Focus. The notion that you can't optimize and enjoy a $13k speaker unless you also add a $25,000 amp and $6,000 speaker cables is killing high-end audio faster than it can find new customers. But it is also incorrect.

>>I hate to ask but are you a dealer/distributor for Audion?<<

No. Not remotely. Not for Audion nor anyone else. I work in software/internet. The Black Shadow I had to repair was my own, and I only know who bought what when people who ask my advice then tell me what they did.

>>If I have caused you SET owners to wet your pants in anger because I hear them as colored/ loud with weak balls than please forgive me for I meant no harm.<<

No one is angry. The objection is the blanket dismissal of SET as weak, low resolution and noisy. Some SET amps are sonically colored and undynamic and in fact that was all too true for most throughout the 90s, during the first ten years of the SET revival in the US. It's why I was late to embrace them. But now there are SET amps that at least with a 101db/w/m speaker are not lacking assertiveness nor are they colored any more so than an ASR is colored in its specific way too. When you hear one, you'll understand. I would respond the same way to someone who said all transistor amps are grating and spatially flat because all the transistor amps they heard sounded as described.

Phil

Morganc,

I don't have Def3 (I do have Def4 and I had Def2). What you really need given the hearing sensitivity you described, is Def4 with the Radian compression supertweeter. But if that's out of reach, you can expect rock at high SPLs to sound less fatiguing in Def2 or Def3 compared to OmenDef, because of the much better cabinet structure and materials in Definitions, and the resulting sharp reduction in cabinet talk. The glare you experience now with rock music in the OD's MDF and simpler cabinet will be gone from Def3. I expect mediocre recordings will be more acceptable becauce high frequency information up to about 12kHz is produced by the FRD, and the nano drivers deliver cleaner, smoother detail than the older FRD, including the whizzer's performance. The nano drivers are a relatively large improvement over the earlier gen Zu FRD in OD.

Further, if you buy Def3, you could discuss with Sean the possibility of wiring internally with Mission instead of Event, or he might suggest a custom cap choice for the high pass filter to the supertweeter. Last, with Def3 you get the B3 connector. If you use Zu speaker cables and have them terminated with Speakon, the B3 continuity all the way to the amp will further refine and smooth some of what irritates you on the top end. And there again, you might consider Mission instead of Event's silver content.

With the powered sub-bass array in Def2&3, you will get a further 1/3rd octave of bass, if your room supports it, and the tunability of sub output from Def4.

Phil

>>...can I trouble you for a summary of what you're currently finding as the Def4s unwind (btw how fast does the sound open up, how many hours before they'll give of their best?)<<

I've had my Def4s eight weeks. Prior experience with new Definitions has been that I'll notice improvements for months, maybe as far as eight to ten months from installation. But in this case I'll say that the tonal completeness has arrived much more quickly than prior new Zu speakers. Now it's a matter of how much more bloom and dynamic ease materializes, and I expect the LAB-12 sub to climb in output steadily, requiring trim to the sub amp's level. The Radian sounded smooth from the start. My specific speakers did have the benefit of additional use at CES (with my consent) before they were delivered to me. If you take delivery when shipping from cold Utah to a cold destination, break-in can take considerably longer. No matter how much factory break-in, cold weather shipping seems to set back the clock on new speakers. Mine were delivered to Los Angeles, via Las Vegas.

>>the greater spectrum of frequencies covered by the new nano impregnated FRDs; they seem to extend deeper into the bass and higher into the treble<<

I didn't actually claim this and if I wrote something that led you to believe I did, then let me correct the misperception, and be more precise: The nano driver actually does have the potential to go higher than the traditional Zu supertweeter roll-in point at 12.5kHz, but that hinge point isn't changed on Def4. But the articulation of the whizzer is certainly greater and more refined. Then the Radian takes over above the FRD's whizzer and it's much smoother, more nuanced, more beautiful and dispersive than the old Zu supertweet. All over, the nano driver is faster, more revealing. more agile. On the bottom end it's different in that you can now adjust the hinge frequency for the low pass filter on the 12" sub, and in part this is feasible because the FRD is capable of a bit more low range than before. Centrally, however, the Zu nano FRD is covering essentially the same acoustic range in Def4 as in Def2, but the sub and super complements are seriously upgraded.

Def4s will probably give their very best in about eight months, but unlike earlier Defs, you'll feel like you're just about there within a couple of weeks of daily use, and maybe as soon as 3 or 4 days depending on whether your speakers have taken an extended cold weather trip. But I'm only 8 weeks in, so I'll let you know if a lot of concealed potential unexpectedly emerges over the next several months.

Phil

>>I got a bit of this when I heard the otherwise very nice Soul Superfly, and when I was seriously considering the Omen Def, Sean (who is very helpful), said he could address it with a modestly priced cap upgrade.<<

There is a Zu tour stop in L.A. tomorrow evening. I had an exchange with Sean today regarding that and asked him about whether a simple cap change or cap + wiring change would suffice to address concerns of a Def3 buyer sensitive to high frequency aggression on mediocre recordings. He said he thinks it is best to do with with the capacitor change in the high pass filter, alone and that it would also fully address the problem. If the speaker ever changes hands or system components alter the nature of the problem, it's easy to revert to spec on the cap, and the full transparency of the Event internal cabling is preserved.

Phil

>>One area I haven't been able to get "right" in my current room is the truly 3D holographic effect....Do the Mk IV's improve upon the previous models regarding this attribute?<<

I've never had any trouble getting multi-axial dimensioning from any generation Definition in my room, but for anyone who has, I have to say that Def4 will improve your chances considerably. It's unity of presentation and the greater precision of projection off the nano FRDs have yielded better spatial presentation for me. Take some time to get toe-in right for your room and listening position and you should be able to snap into focus a nicely dimensioned soundstage.

>> I swear I could make out the lips, neck, body, legs of musicians...it was so "dense, palpable, and 3D" that it really was hard to believe. Is this kind of experience possible with the Mk IV's and a proper SET? <<

Normally I'd say to someone who seeks this but has never heard it that they have to question whether they are able to hear this way. Not everyone processess the sonic cues that register on their eardrums. But since you have heard it prior, then I say yes, and in fact well-executed SET (wideband, fast, good unity) gets you closer than push-pull topology, generally. But sloppy SET won't.

>>...but am curious if an 845 SET with the Def Mk IV's has the potential to duplicate what I heard with the Proac/Cary 805?<<

Yes, but again it depends upon specific amp choice, and then you can usually improve all aspects via careful replacement of stock tubes. Generally, 300B amps don't have the bass discipline to be effectively paired with Definitions of any version. There are exceptions, but they usually aren't cheap. The Audion Golden Dream, Coincident Frankenstein and Audion Silver Night are in the realm of Def-compatible. Also, 300B push-pull amps. But the 845 and 211 big-glass tubes are much better mates to Definitions, if part of very well designed and executed circuits.

>>I refuse to trade any of the strengths of my current system though!<<

Start with your Atmasphere and draw your own conclusions. It's a great combination to begin knowing your next move, if one is warranted.

Phil

Charles,

I've heard various PHY-based speakers, including some Tonian, Ocelia and DIY, but not with my own room or gear. I'll say that PHY speakers haven't shown me the same combination of efficiency, shove and tonal neutrality that Zu has achieved in recent years (Druid 4-08, Superfly, Def4) but the essential elements of holistic character, good-to-great tone density, speed and phase-coherence are quite audible in PHY-based speakers. And, I'd understand someone either subjectively preferring their euphonics, or in the absense of having heard a Def4, preferring a PHY full ranger or coax "1-1/2 way" over *any* passive crossover multi-driver speaker. PHY speakers don't have the same power handling as Zu, nor that sense of ability to convey both voices and violence that Zu does well. But that driver is fast and articulate and Ocelia instances of PHY in particular produce beautiful sound. I'm much less endorsing of the ribbon tweeter Tonian uses in most of its speakers, but others may disagree.

At two price ranges in the current line, Zu has achieved truly exceptional balance and holistic presentation in Superfly and Def4, by any standard, with the rest of the line representing really well-engineered and chosen compromises for reasons of market-expanding cost and I expect more of both are coming. With all these full-range-driver based speakers, the power amplification takes on a disproportionately large role in defining the character of the system.

Phil

>>If I understand you correctly, you are saying to experiment with amps, presumably good SET's, and determine if this is the correct path for me?<<

I think a subset of high-quality SET amps -- particularly 845 based -- are ideal for Definition systems, but you already have a very fine amp in the Atmashpere OTL so you should begin with that; get accustomed to the combination and see how it satisfies you. Once you have that baseline, then try Audion, Sophia or maybe Melody or Consonance 845 SET amps if you find you still have the appetite for trial.

>>From what I have read, I think the Audion may be closest to what I'm looking for, IF SET is what I'm looking for. Does that make sense? Are there any distributors in the US that would allow an in-home audition?<<

The US importer/distributor for Audion is Gary Alpern, reachable at his web site, http://www.trueaudiophile.com. The unfortunate state of high end audio retail is such that the usual burden is on the prospective buyer to find a way to hear the gear they are interested in, or find home trials from online sources. I don't know where you live nor how far one of Gary's retailers is from you, but start by asking him.

Phil

>>One thing I have overlooked is that the Melody 300B did work well with my Zu Druids, a 12 ohm load versus the Def's 6 ohm load.<<

300B amps can be a great match to Druid, standard Omen and any other Zu speakers with a lower limit of roughly 40Hz or above, regardless of impedance. But sufficient execution of 300B SET topology, especially in OPTransformers and power supply size, stiffness and regulation, to maintain linearity into the deeper bass regions Definitions can attain is generally a more expensive proposition. I've heard Melody SET gear, but not their 300B amp so can't comment about its suitability for Definition specifically. I have however heard very good bass from 300B SET on Definitions, in the form of the Coincident Frankenstein monoblocks, the Audion Golden Dream PSET monoblocks (recapped specifically to improve this) and the novel Butler current dumping implementation wherein a single 300B per channel primarily governs sound quality in tandem with a muscle amp. DIYhifisupply has an interesting 300B amp in a similar complementary scheme with a "muscle SS amp" and in that case, the amp is switchable between pure 300B SET operation at 7/7w, or fusion operation at 40/40w. I haven't heard this amp but having heard some of their other reasonably priced tube gear, there is reason for optimism this may be a very effective affordable triode amp for Definitions.

Further, I've found the KR Audio 300B tube to significantly contribute to more controlled deep bass quality from many 300B SET amps, though some of the hardness it contributes to bass discipline can change the midrange and treble euphonia some folks seek from their 300B amplification, from lush to a more aggressive punch and slam at some expense to midrange tone density. I happen to have found the right optimization for that tube in the recap of my Golden Dreams that also improved the objectivity of the Sophia mesh plates, correcting their euophonics while also leveraging the KR Audio's assertive discipline while dialing up their beauty and tone.

300B amps, if optimized for good linearity at full bandwidth, can be stellar revealers of the obscured musical event, so shouldn't be overlooked. It just may be a more expensive proposition to get the right match of amps/tubes/speaker than many people hope.

Phil

The Sophia 845 current chassis are 206-driven and tube rectified. I don't think they offer the 6sn7-driven version (at much lower cost) anymore.

When both versions were offered, the gulf between the 6sn7 and 206 versions was very wide. The 6sn7 version of the Sophia 845 was a fine amp but not exceptional. The 206 driven circuit is much more energetic and toneful. Like most amps that are tube rectified, the tube rectifier is a real point of tunability, with substantial effects on dynamic performance, macro/micro dynamic perceptions, tone density and degree of slam.

Phil

>>...so please Sean and everyone at Zu, don't tempt me a few years down the line with Def5s etc....<<

There's ALWAYS something next. You just have to know when the train has traveled far enough for you.

Phil

>>Are they improving further as they open up?<<

Yes. But Def4 breaks in much more rapidly than Def2 did, with then a long tail of very gradual improvement. The interval from set-up to quality sound is quite brief.

Phil

Perfect. Def 4 is the single most convincing speaker of practical economics, amp requirements, size, and universality of room application I've encountered in 40 years of looking for gear in this realm.

It also fits perfectly with amplification decisions that have proven stable for seven years. I changed one preamp out of two systems to more closely complement the change from Def2 to Def4. And Def4's superior conveyance of digital listening sparked a new investigation of DACs and an imminent server configuration. Nothing but positives.

Phil

My own experience with ASR is a clean, smooth but bleached aural presentation; good without regard to cost but tonally incomplete in any case and not retrievable if your criteria for fidelity include holistic representation of the leading, middle and decay of a note, as well as many simultaneous notes together. ASR produces an illusion of fidelity rather than the actual facsimile of it. Very good. Very expensive for what you get. Not far enough on the arc of convincing musicality. But I fully understand why some people are attracted to the clean, desiccated sound of ASR along with many other advanced but flat solid state options similar.

Phil

Guys,

It's not a popularity contest. A few people or even many liking a sound isn't persuasive to me. You have to convince me first you know what real instruments sound like in unamplified circumstances for me to assign any special credibility to your view of ASR. But I have no argument with someone liking a sound, even if it's "wrong." No harm in that. Just don't expect my view of it to change unless the ASR meaningfully improves their amplification so I hear a better result. Until then you can quote 3 or 3000 converts. It's irrelevant. If majorities reflected good judgment in hifi, there would be no Bose, B&W, Boulder, Wilson or Krell.

I don't think ASR makes bad amplification. I just can't listen to its truncated, desiccated tone. I don't doubt for a second that ASR sounds fine -- until you hear better, and until a listener thinks seriously about how music actually sounds. It's pretty good for SS, bested by just a few others in that topology. Build quality is *very* high. At its price and even lower, however, there are better alternatives for approaching the original sound. It really doesn't matter that we don't agree. You'll put the ASR in your rear view mirror sooner or later, too, just like every other amp you've championed in the past. It's OK! Enjoy it while you can. You're in the realm of the white hats with your speakers anyway.

Phil

Kharma + ASR. Two wrongs together don't make a right. But there's a larger point to be made: A review of something I haven't heard *can* give me a clue of what to take a chance on, particularly if I can find reviews of other components I *have* heard, by the same writer. Then I can triangulate how much credibility to assign the new review based on what we agreed or disagreed on in the past. But a review of something I *have* heard isn't persuasive or actionable to me in the least, if we reached different conclusions. So save it -- anyone can find a favorable review for *anything*.

Do power cords make a difference? Well, yes, in that they tend to bring their own sound. But if an amplifier needs a specific power cord to sound musically-convincing, and without it it doesn't, then said power cord should be supplied with the amp if it is so elemental to the performance of the circuit. "Dude, you didn't have the right power cord..." doesn't cut it. I'm pretty sure even ASR wouldn't endorse that proposition.

Somebody mentioned silver. Silver's advantage is simply in being the superior conductor, granting it wideband transparency. If silver doesn't sound good it's because there is a problem present upstream that silver isn't hiding. Dielectrics, wire weaves, etc. have their effects and can overwhelm the role of silver vs. copper vs. palladium, etc. But silver doesn't add detail or dynamics that aren't there in the first place. Other conductors may subtract some, which can be a good thing if something upstream of the speaker cable -- whether the amp, the source or the recording itself -- either contributes some hash or isspatially, tonally or harmonically incorrect. Silver's advantage is to simply reveal more. If silver and ASR don't work well together, the fault is with ASR, not silver by itself. It's not that silver is not good enough for the gear; it's that the gear or recording isn't good enough for silver, as has often been the case with digital.

Every power cord, speaker cable and interconnect introduces distinctive sonic character. Ideally we try to minimize this reality. A lot of people use these cable elements for sound-shaping, effectively rendering them fixed-parametric tone controls. Do what you want. My choice (and recommendation) is to assemble musically-convincing high-resolution gear that sounds proper in the aggregate on any reasonable cabling, and then optimize further with a neutral wire loom (which generally isn't correlated to cost).

Phil

>>Friederich Schafer has worked on that design for over 30 years. Maybe he should hire you as a consultant?<<

I commend his persistence. I heard the early amps. I had hopes for more progress by now.

>>Silver is only nominally better as a conductor compared to copper (6% better). Translates into "louder" and not an increased bandwidth. Why is it that SET owners gravitate to silver? Hmmm.<<

You are correct that the percentage improvement of silver's conductivity over copper is small, numerically. In coils or in wire weaves however, the bandwidth and revelatory differences between metals can be real in addition. Having worked on silver vs. copper based audio product development efforts, I am speaking of both measured and audible differences, first-hand. Regardless, compensating for any loudness difference is easy. More to the point, I get equally good sound out of SET amps with copper, copper + silver content and silver cabling. But the middle option does it at moderate cost. I don't have a bias for silver cabling for silver itself. I don't really care what's in a cable as long as it is sonically neutral or close to it.

Put another way, if an amp is musically convincing, it ought to be also credible on Paul Speltz' inexpensive Anti-Cables, and then the owner can decide how far to take cabling. I know I could do that with any SET amp I consider exceptional on its merits.

>>Why not minimize second harmonic distortion?<<

The best SET amp designs do minimize 2nd order harmonic distortion. They just don't go so far as to incur the downsides of negative feedback to push that one performance attribute to vanishing levels. There's more to perception of fidelity than vacant harmonic distortion.

>>I have talked at length with a manufacturer who makes what many consider the best tube amplification in the world, and he felt that SETs present so many disadvantages from a design standpoint that they were not worth pursuing despite the plump and pleasing midrange.<<

He's entitled to that view. Obviously SET amp designers disagree. Great SET amps don't have a "plump and pleasing" midrange. There's nothing "plump" about the midrange of the most convincing modern SET amps. It's the midrange qualities that you describe that kept me from embracing early examples of the SET amp revival. You just have to hear more credible examples, properly tubed. What they do have is a tonally complete, realistic midrange. What the design primarily gives up aside from high power is some ultimate bass control. It's a small price for the gains in real music fidelity in 90% of the aural range.

>>No need to sweat the details regarding wire, conditioning, and even your room.<<

If you choose the right gear to start with, the details are far easier to sort out. Music is the intent, not fetishism. I think it's great ASR amplification works for you. I'd rather see people happy in this pursuit than frustrated and chasing their tails.

Phil

Overall, Zu makes a line of speakers that is amp-friendly to a wider range of electronics than any speaker brand I can think of. 101db/w/m efficiency that can also handle high power tube or solid state amps without distress. Relatively flat impedance curves, controlled floor & ceiling effects in Omen Def and Definition, check. Omen, the older Druid and Presence are/were ambidextrous about solid state or tube suitability. Superfly, the upcoming Coax and Definition "work" with anything but are considerably more exclusive about amplifier compatibility to sound musically outstanding (though this isn't strictly a cost issue, as the synergy between Quad II & II-Forty and Zu demonstrates). They are less forgiving of compromises in solid state designs than same in tube amplifiers, but overall there is a much narrower range of optimum amps for Superfly, Definition and the upcoming Coax. Still, people who don't like or don't want a tube amp have a half dozen compatible (and exceptional) solid state brands that make music with Zu. And sure, I'll put ASR among them. I think you can get much further with the right tube amplifiers but that doesn't really matter unless you're asking for direction. For whatever reason a Zu owner wants or prefers solid state amplification, they should have it. The issue here is that these forums become a permanent record of advocacy on the web.

Zu Definitions solve so many problems in music presentation that the amplifier just has to be good to put you in the realm of convincing hifi. The reason these amplifier topics become controversial is because the speaker is so good that once you hear it with even reasonable associated gear, the human brain (being a hungry beast) gets focused on extracting the nth degree of performance. And there's another thing: Zu upends the traditional weight in hifi given to the source. The amp/Zu interface becomes -- after the speaker itself -- the single most influential element in your system's sound. In a Zu system, much more rides on the amp selection than in systems built around most other speakers. Hence the heat the topic generates.

Phil