@jafant Nice! What amp were you previously using? I imagine you are happy with the SQ. Does it play loud enough for you?
Assuming *balanced* connection (please tell me you’re using this and not the RCA connection) and full scale output (common on rock recordings but not necessarily classical), your combination of AX-5 and DX-5 will begin clipping at “40” or “41” indicated on the AX-5 volume display. With DSD recordings, this will be at indicated “44”. Ignoring room interactions, I estimate this somewhere in the range 95-97 dB with the CS2.4.
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@jafant You might be interested to read the new AX-5 Twenty review in Hifi News https://www.hifinews.com/content/ayre-ax-5-twenty-integrated-amplifierOn the bench, it produced 650 W into a 1 load under “dynamic conditions” (I think this similar to the tonebursts that Stereophile did for an interval, more music like than steady state test signals; not specified whether that was for one or two channels driven). Eye-popping how much more powerful the Twenty is compared to the original even though Ayre did not change the spec. Pretty well confirms what my ears hear paired with the CS2.4. |
Sorry for the confusing post. Other than the mechanical crossover, the rest of my post was intended as fantasy. And now you clarified that the crossover bit is also imagination.
Happy Thanksgiving |
@jafant No, I haven’t played with the fuses. Until the CS2.4, my tweaks were on the low budget end (mini-sandbox for my TT, cables on wood blocks, and the Ayre IBE disc). With the FST-sourced crossovers, it seemed very likely that an upgrade in parts quality would yield sonic benefits. Indeed, that is what I heard. The Ayre is such a great piece, I doubt I’ll ever afford anything better. Please let me know if you play with ultra fuses. |
@tomthiel I recall you also wrote the 7.3 coax would have had a mechanical crossover. Carbon diaphragms, sealed bass and top shelf passive parts would have made for an absolute world beater. |
If ultra low distortion is so important for SQ why isn’t Halcro widely regarded as the best ever? |
Ayre power amps are also a great match with Thiel 100 My AX-5 Twenty and CS2.4s are singing. Years ago I ran a pair of CS1.6 with the AX-7. Also nice other than I yearned for more bass. And my only experience with the CS7.2 was paired with, I think, the V-1. That system was just short of the very best I’ve heard. |
I have bragged about those yellow caps as state of the art, and they were in their day Oh, no! Time to remove the radiator again? Lol I do occasionally wonder about different bypass caps on the CSA coax feeds. We went with Multicaps but, in hindsight, I’m curious to hear something like the Audyn True Copper Max or Jupiter. Likewise, wonder how the Path Audio resistors better the Mills MRAs, if at all. Then again, that was a lot of work to make one change in one channel, wait for it to burn in, and carefully compare in mono. Maybe I’ll just listen to music and be happy rather than compulsive? :) With the 3.7, I wonder if Rob Gillum’s experience is related to those massive ELs which cannot practically be upgraded due to size and cost. But, yeah, the Mills seems like low hanging fruit that is likely to make a nice sonic upgrade and for not much money. |
@thoft I think V-1s were in the range $8-9k when new, depending on the version. So you might find one for about $4k or less? I think Ayre stopped making them shortly after the MX-R was introduced ~15 years ago. But I’ll bet they will still upgrade any version to the ultimate one, V-1xe. |
The Wilson approach has certainly won the day
Could be argued their success is partly an artifact of their pricing. Here is Charles Hansen’s take on Fremer (and most of the audio press, by extension; from an audioasylum post):
a) The more expensive the product, the better it must be.
b) Wilson loudspeakers are the best on the planet, presumably because they play really loud, have super spectacular bass thump created by the +10dB bump they all exhibit at 70Hz, and are ungodly expensive (see (a) above).
@tomthiel thanks to you and Jim for bringing a superb level of performance at price points that most can afford!
Again, Charles Hansen from an audioasylum post:
The high-end wouldn't be where it is today without the contributions of Jim Thiel and Richard Vandersteen.
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I share your bias @tomic601
If I win the lottery, probably go straight to Vandy 7 and MX-Rs. Until then, very happy with my modded 2.4s and AX-5. IME, gotta spend a lot of money to shore up the few weaknesses of my system. In fact, the most cost effective fix would be to add Vandy Sub 3s which would shore up bass extension and definition. But not motivated to add two more large boxes to my living room.
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similar to the improvements in beetlemania's 2.4 upgrade. Two years later, I remain of the opinion that these are my last speakers. Compared to the very be$$$t speakers/systems I’ve heard, the list of faults is short:
1) no audible output below ~30 Hz;
2) low bass is not as resolved as a quality sealed box design (eg, Avalon Ascent);
3) image density not SOTA (eg, TAD Ref One).
1 is noticeable only on music with organ. 2 is only apparent in direct comparison. Those two faults could be addressed with, maybe, a stereo pair of the Vandersteen subwoofers and I would have a near SOTA system at a relatively “affordable” price (but not excited to have two more large boxes in my living room). Meanwhile, my sonic priorities - resolution, transparency, and neutrality - are very close to the best I’ve heard at any price.
Bravo, Jim and Tom Thiel. Thank you. |
@snbeall Finding a stereo pair of Thiel subs with the appropriate crossover is a tall order. And, yes, lack of amp service is an issue (I think Rob Gillum only services speakers). Finally, the Vandersteen room correction is very appealing (although I would have to send my integrated amp to Ayre for an internal crossover). But this is academic as I’m not seriously considering this move. I am aware of my system’s minor shortcomings and enjoy it nonetheless. Immensely. I mean, it’s not like it sounds broken.
:) |
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@snbeall I don’t think there is any single page or post that summarizes what I did or why. Relevant posts begin January or February, 2018. I made my final changes about one year later. So, look at pages within that interval, especially posts by Tom Thiel. |
@pieper1973
The thought of putting Dueland caps into CS2.4 is wild to me. Even if Dueland makes the proper capacitance values (I don’t see anything close at Parts Connexion), the price would staggering. Multiples of the original price of the full speaker. But I would love to hear the outcome!
I suggest taking Tom Thiel’s advice, go with Clarity Cap CSA. Ideally, get full capacitance in single caps. 14 and 28 uF are tough to find but I would avoid going with 13+1 and 27+1 as in the original CS2.4. Running caps in parallel, I would go with something like 10+3.9+0.1 and 18+10. Try to get a more even balance among the two bigger paralleled caps. The 0.1 uF bypass is where you might go crazy and install a super-ultra bypass like a Dueland or Jupiter (even those are expensive!). You could add a 0.1 bypass to the 28 uF position as well.
Tom pointed out that the higher voltage models (eg, 630 V) have thicker film which is desirable, especially in the coax feeds. But I heard a difference even in the woofer shunts with 250 V version sounding more impactful than 100 V version of an otherwise identical cap. If your budget extends to Dueland$, definitely you can afford to replace the electrolytics in the coax shunts to film caps. Clarity Cap is a great choice for these, although be warned that their size is far greater than the electrolytics. That is, you might be challenge to fit everything within the passive radiator chamber.
Definitely upgrade the sandcast resistors to Mills MRAs or, if your pockets are Dueland-deep, maybe try Path or Dueland graphite resistors. Again, those ultra re$i$tors are hard to find in the proper values for the CS2.4.
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@improvedsound
That looks really nice! Great job. Curious what brand/model is the 0.1uF bypass?
I would have elected to also use CSA for those 100uF shunt caps but I know those are very large and expensive. That way you get away from electrolytics and their propensity to drift with age and it’s quite possible they sound a touch better, too.
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From Rob Gillum:
“The [Cs2.4] crossover can be accessed through the passive radiator opening. The base is not removable, as it is screwed, and glued. To access the crossover, you must remove the passive radiator screws and let the passive radiator drop into the cabinet. It can be rotated 90 degrees, and removed while servicing. To re-install the passive radiator, you can place your fingers at the surround, pressing outward to hold in place while re-installing the screws that hold bit in place.”
It is not glued but it is a bit of a puzzle to orient properly to get it out (and back in).
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@improvedsound Assuming all values match OEM and the connections are consistent with the schematic, that board should be singing. From your images, I see nothing out of place although I can’t see everything. Total resistance of the coax board should be, IIRC, 32 ohms. If all values and connections are good, that suggests the foil coil is the culprit. I also put foil (Erse) in that position, would have to dig into my notes for the gauge.
Could also be you just hear things differently than I do. But there are now at least 3-4 of us who modded at least the coax board on CS2.4 and reported good results. I suggest verifying all values, connections/layout, and total resistance. If those are good, put the OEM coil into that suspect position.
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@improvedsound
My L5 inductor (ie, the one on the coax board, paralleled with 28 uF cap and 2 ohm resistor) is Erse FoilQ, 16 gauge, 0.15 mH.
I have all Mills MRA12s, the 30 ohm position I used paralleled 60.2 ohms for improved cooling.
The biggest difference I see in your pics compared to my build is that I have full capacitance in single caps. I *greatly* benefitted from tagging along with @tomthiel as he explored his “renaissance” project. Not to mention his considerable coaching.
All main caps are Clarity CSA. Coax feeds (14 and 28 uF) are 630 V, subfeed (43 uF) is 250 V, and shunts (100 uF) are 100 V. Each of the feeds and subfeed are bypassed with Multicap RTX at just under 1% (eg, 0.1 uF on the 14 uF cap). The shunts are bypassed with the 1 uF yellow caps common in classic Thiels (Elpac?).
That said, Your use of paralleled CSAs (eg, 18+10) should be fine, certainly not worse than the original CS2.4 which used 27+1. Best wishes resolving the issue.
[edit: post number 11111. Look at what you did, @jafant !!]
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Excellent point, @imhififan
During my build, I stopped at several points to compare changes. I always allowed 100-200 hours before critical listening.
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Relax Beetle ... you're sitting pretty till that time
Oh, don't I know it! I remain *very* happy and full of gratitude for all your help, @tomthiel. If someone else has better sounding 2.4s I wanna know about it. So, I was kidding but also curious to hear the PURs.
I remember telling myself, when I last buttoned up the binding plate panels after installing the Cardas, that I wasn't going to take the boards out ever again :)
Curious if you have an opinion or knowledge about how to pair "main caps" if the full capacitance is not available in a single cap. Is it best to optimize balance between caps (eg, 7+7=14) or is there some degree of leeway (eg, 10+3.9+0.1)?
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Perhaps semantics but I think of electronics responsible for “black backgrounds”. I suppose the analog in the speaker realm is “transparency”.
IMO, Thiels are generally very transparent. That was one of the strengths of my 1.6s. That said, I heard a subtle “glassy” quality in the midrange when I bought my 2.4SEs in 2018. It might have been the FST-sourced crossovers (lower quality parts compared to crossovers built at the Lexington shop) or, maybe, damaged resistors (the OEM resistors showed evidence of overheating when I replaced them). That quality was mostly, if not completely, remedied by the Mills resistors. And my final boards not only have zero trace of that anomaly but the transparency is topshelf, equivalent to the very be$t speakers I’ve heard.
It could be that your 2.4s are more revealing flaws in your electronics rather than the other way around. |
Hi Jafant,
It appears you misread my post. I vastly prefer my Tom Thiel designed boards over the FSTs. And it’s been about 15 years since I’ve heard the 2.4s with Lexington boards but, other than the Clarity SAs in the coax feeds, I would take the Lexington over FST on parts quality. In addition to the loose coil windings, the FST had polyester caps rather than polypropylene.
Regardless of that, I consider Thiels to be transparent in general. |
@jafant I would be very surprised if your late production SEs did not have the FST boards. Early units might have Lexington boards, Rob Gillum might be the only person who knows.
Read the following knowing that I am an insane person:
If you’re going to upgrade FST boards, my advice is pretty much replace everything. Well, on an extreme budget you might just upgrade the resistors to Mills. But the parts quality is disappointing on the FSTs. The Clarity SAs are good but even those are outpaced by the newer CSAs.
For units with Lexington boards, the parts quality is higher (those Clarity coax feed caps are the best OEM coax feeds regardless of standard or SE version, or Lexington or FST). On a budget, you might just upgrade the resistors and feed caps. Standard CS2.4 owners with Lexington boards could have something notably better than the SE version with just those “simple” changes. Even reaching higher, there are several coils and a cap or three that are worth salvaging. My extreme makeover has 3/5 coils and one bypass cap that are equivalent to Lexington. But I retained nothing whatsoever from the FST boards, not even the hookup wire and binding posts.
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Re: Clarity PUR, this is getting above CS2.4SE, all the more so if you also upgrade the resistors and other caps (and if you have an FST board and also replace the coils).
I recall @tomthiel wrote about PUR some weeks ago. I had the impression this line is the next step in the progression SA>ESA>CSA>PUR. But the brochure makes me wonder if PUR is also a step above CMR, which had been the top-shelf Clarity. Curious to see the pricing.
Might be tough to find 12 others willing to pony up for custom cap purchase. I hope I’m wrong. But not a dealbreaker to parallel, for example, 18+10 uF (or, I see 20+8 is also possible). That said, I would not parallel 27+1 or 13+1 after reading an anecdotal report this range of bypassing *might* yield deleterious results. I know the 1 uF bypasses were specified in the original CS2.4 but maybe not a coincidence that Jim Thiel went to full capacitance in single caps for the SE?
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Thanks for the post, @tomthiel. Interesting history of the origin of those 1 uF and how they were later used to improve performance of the Solens in other models.
I don’t see “PUR+” on Clarity’s website. Are those the 800 V PURs? Have you heard reports of how PUR compares to CMR? I’m curious to read reports of PUR sonics. Maybe I’ll become convinced to upgrade the CSAs, at least in the coax feeds.
Can you say more about your bypass comparison? I’m imagining you compared full-value SA/CSA against SA/CSA less 1 uF + 1 uF ELPAC. Your post suggests “capacitor tizz” is the result of discontinuities among paralleled caps. That makes sense to me but I’m wondering why this seems *not* an issue when bypassing with even smaller caps. As you know, I bypassed the CSA coax feeds with Multicap RTX at just under 1%. In my comparisons, the bypasses improved transients and, *maybe*, further improved resolution. I did not hear any deleterious effects.
To get that 14 uF on the CS2.4 coax board, I’ve been suggesting DIYers get 10 + 3.9 CSA and add a 0.1 bypass (Multicap RTX, Audyn True Copper Max, or Jupiter copper foil depending on budget). But maybe the best course is a pair of 7 uF which, apparently will be available per Clarity’s website (although I’ll be surprised if all values on that sheet are stocked by PartsConnexion and Madisound). Might still be worth adding the ~1% bypass for improved transients but your post implies paralleled main caps should be balanced as evenly as possible. And what about that 28 uF cap? Do you think cap discontinuities would be audible with 18 + 10 uF? Or would it be worthwhile to bundle 4 x 7 uF?
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@pieper1973
The 250 V is not a “problem”. The OEM caps are only 100 V. But as @tomthiel explained, the higher voltage caps have thicker film which is desirable. So, a 250 V PUR would almost certainly sound way better than the OEM 100 V Solens or CYCs. But even better performance is possible with 400 V and 630 V versions. I heard an improvement with 250 V over 160 V CSAs on the woofer boards, and those are shunts, not direct feeds. It wasn’t a huge difference, and I told Tom I could understand a manufacturer going with the 160 V to meet a price point, but I was willing to pay for the improvement.
In my communications with Rob Gillum, he seemed lukewarm around my upgrade project. I suspect his stock is limited to SA at 630 V (I might be wrong!). One clue is that Thiel only built ~200 out of a planned 300 pairs of CS2.4 SE. Those SAs will certainly improve the sonics of the original CS2.4, even more so if you have boards sourced from FST with the CYC polyester caps. But a DIYer can do even better in 2022.
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Wouldn't upgrading the 2.4 value caps to Clarity CMR's be rewarding enough ?
If I understand @tomthiel correctly, the PUR is an upgrade of the CSA and the CMR is also upgraded. So, yeah, CMR would be very rewarding if your wallet is that thick. In early discussions with Tom, I advocated using CMR at least as bypasses. Every report I’ve read indicated better sonics from CMR compared to CSA. Getting full capacitance, however, in CMR for a Thiel XO would be wallet crushing. Tom gently steered me to CSA which is more in line with the Thiel ethos regarding performance/value. Tom had CMR that I could have auditioned as the 1% bypasses on the coax feeds but I was exhausted of comparisons by that time and I was already thrilled with the sonics from CSA bypassed with Multicaps.
So, PUR is an improved CSA at about 20% added cost. CMR is probably still better than PUR? But a 10 uF CSA 630 V is $22.13 at Parts Connexion whereas the same in CMR is $91.78. So, if PUR gets you most of CMR sonics at a fraction of the price . . .
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in some ways the PUR (CSA with thick end caps) outperformed the CMR
Seems like Madisound and PartsConnexion will want to sell most of their current stock of CSA and CMR before investing in PUR. Might be a while before we see PUR at these outlets.
Crap, I’m feeling a twinge of audiophile nervosa. LOL. Hard to imagine I can get much more out of these 2.4s but that’s also what I thought before the upgrades to my Ayre electronics.
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Tom, your post suggests all SE versions are FST. On the ‘net, I found a pic of an SE crossover that looks Lex-ish (but with the Clarity SAs) and a video of Gary Dayton showing an SE crossover that looks neither Lex or FST. I suppose there are one or two prototype SEs with Lex boards?
I wonder if the quality of the FSTs slipped over the years. Perhaps they started as “Lex equivalent” but downgraded parts quality with time? I imagine all FSTs are on printed circuit boards but perhaps they initially used MKP caps and had better quality coils. The seller of my SEs claimed they were built in 2012, which is credible given the late serial numbers. That is 3 years after JT passed and the year Thiel Audio was sold. Maybe the downgrade in parts quality is restricted to late pairs?
Regardless, the CS2.4 has superb drivers and a quality cabinet. In my experience, a crossover upgrade yields a speaker that is near SOTA other than bass extension and definition. That’s the best you can ask for anywhere near this price level.
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I wish Rob could hear my 2.4s. His upgrades can go a whole ‘nuther level, IMO, given that he is probably only replacing the coax feed caps with the SAs.
The SE version also received rave reviews from Enjoy the Music and Ultra Audio. I wonder about the crossovers in the review pair (probably the same pair for both reviews?). Were they Lex or FST. And if FST, with polyester or polypropylene caps? I also wonder if the “glassy” midrange anomaly I heard was because of overheated resistors from a previous owner. I was mostly happy when the SEs arrived in my system but they were not without flaw. @tomthiel the upgraded boards made this one sublime speaker!
Wes Phillips was one of my favorite reviewers. I trusted his ear and he was also an excellent writer. |
I certainly do not hear a glassy presentation with my Ayre QB-9. But even if the Ayre is guilty of this sonic trait, as you suggest, that is *not* what I heard with the SEs when I first got them. It was a trait not apparent with my Vandersteens or Thiel CS1.6 and it was mostly, if not entirely, cured by replacing the OEM resistors with Mills. And the Tom Thiel crossover upgrade brought the performance up to near SOTA other than in bass performance (no help for that given the 8” driver and passive radiator) and image density. So, what I’m talking about has nothing to do with the source or amp. |
@jafant I honestly do not have a full accounting of what I spent but I’m pretty sure it was north of $1000. I mean, I replaced everything except the drivers and cabinets. I have Cardas hookup wire and dual Cardas binding posts, fer-cryin-out-loud! Even the coax shunts caps at 100 uF each are a low voltage version of the CSA. My 2.4s are really tricked out. About the only stones left unturned were Path Audio re$i$tor$ and Jupiter copper foil bypa$$ cap$.
I do recall I spent about $100 on the Mills MRAs from Sonic Craft. But that was 3 years ago, so prices are likely higher now. Still, that’s a pretty good deal for upgrade in SQ from the sandcast resistors. I bought some stuff from Parts Connexion and other outlets but a lot of it came via Tom Thiel who was working directly with Clarity. And 6/10 coils came from Rob Gillum who had a stock of Lex-equivalent coils (Erse, maybe Jantzen, rather than FST).
I suspect a judicious DIYer with Lex boards could probably get about 80% of the SQ of my upgrade for, maybe, $500. Mills MRAs throughout, Clarity CSAs on the coax feeds (plus, maybe a single bypass cap - I used Multicaps but am really curious about Audyn True Copper Max or Jupiter in the bypass position), foil type inductors in the feed positions, refresh the 100 uF electrolytics with Jantzen Premium ELKOs. Those of us with FST boards might choose to reach deeper into our wallets, especially if the woofer caps are MKTs. If you have FST boards like I did (MKT caps and loosely wound coils), I suggest replacing everything.
But, remember, I’m insane :) |
No, jafant, I don’t have any upgrades planned. I had my Ayre QB-9 upgraded to the Twenty version last year and that might be my final upgrade. My system is really dialed in. In 2019 I was able to hear a reference system and my system only comes up short in bass extension, bass definition, and image density. Those are only noticeable in direct comparison. I am aware of those shortcomings and nonetheless fully enjoy my system without upgrade neuroses.
Meanwhile, my retirement is on the horizon and even now it would be a financial reach to address those minor deficiencies. So, I’m happy with my system and care not to obsess over how to improve it. |
I bought my CS2.4SEs from TMR. I had a positive experience but the cabinets had more damage than advertised. Not just the usual small scratches but one bottom corner is a bit crushed, suggesting the speaker was once dropped. But they were well packaged, in original boxes, on a pallet for delivery to my home.
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@jmbumgarner01 Here are CS2.4 crossover access instructions from Rob Gillum: The crossover can be accessed through the passive radiator opening. The base is not removable, as it is screwed, and glued. To access the crossover, you must remove the passive radiator screws and let the passive radiator drop into the cabinet. It can be rotated 90 degrees, and removed while servicing. To re-install the passive radiator, you can place your fingers at the surround, pressing outward to hold in place while re-installing the screws that hold bit in place. |
most of the way to these speakers’ potential once I replace the resistors. Super cool that you have Lexington boards and upgraded the coax feeds to ESAs. I am confident you’re getting better SQ than the SE version (FST boards plus SAs on the coax feeds). My SEs had the FST boards with CYC MKT caps (other than the Clarity SAs on the coax), air core coils but with less than optimal winding integrity, and sandcast resistors (manufacturer unknown but similar construction to sandcasts from Xicon or Erse). Additionally, the printed circuit boards looked to have been somewhat burned underneath a couple of the resistors, so perhaps these were damaged by a previous owner playing very loudly. During my upgrade, I did not listen to each single change I made so am unable to pinpoint everything. But I did pause at several stages and compared modified and reference channels in mono (using Roon to produce a mono mix). Comparisons I made were: 1) FST boards with sandcasts v Mills; 2) FST with Mills v “Tom Thiel boards” (CSAs though out, including on coax shunts, Lex-equivalent coils including Erse FoilQ in feed positions, and Mills resistors); 3) Tom’s boards with and without RTX Multicap bypasses on the coax feeds; 4) 160 v 250 V woofer shunt caps; 5) OEM binding posts and hookup wire v Cardas binding posts and hook up wire; 6) single v biwiring from the amp. I heard at least some difference from each of these changes. In significance, I rank them: 1) CSAs + Lex/FoilQ coils (better resolution/textures/microdynamics; more open, clear, and transparent); 2) Mills MRAs (mitigated “glassy” midrange, improved bass impact/soundstage/“ease”): 3) Cardas wire and binding posts (more open/clear/holographic/“immediate”); 4) tie among biwiring (more relaxed/liquid/dimensional), coax Multicap bypasses (better “jump factor”, smidge more resolution), and higher voltage woofer shunt caps (bass “heft”, ease of presentation). So, @sdecker I strongly recommend you upgrade the resistors. That’s a nice upgrade for short money. Several sources indicate the CSA improves on the ESA but is it worth your time and effort? I recall you kept the 1 uF bypass caps, so maybe “yes” (ie, get full capacitance in a single cap or, if forced to run parallel, have the smaller cap represent a larger portion of the total capacitance). In your shoes, I would upgrade the *feed* coils to FoilQ or Jantzen wax foil (one coil on each board). I did not directly compare the foil to air core but I think it’s worth trying this given that you can get all four foil coils for <$100. I would replace the 100uF coax shunts if only because electrolytics drift with age. The best solution is to go with film caps as they sound better and will last far longer but those are also far more expensive and larger. Sticking to electrolytics, I would pick the Jantzens. The other changes I made fall in the category of diminishing returns (although I had a big smile on my face with the Cardas, it seemed to snap everything into focus). You might try a small bypass on the coax feed caps. Something like a 0.1 uF Audyn True Copper Max, Clarity CMR, or Jupiter copper foil. I don’t know that these are better than the more affordable Multicap but am curious. I have each coax feed, including the 43 uF subfeed, bypassed at ~1% but you might try a single 0.1 uF on the 28 uF cap. |
@vair68robert
So, you have installed Cardas hook up wire and compared it to “original” and “new” Thiel?
IIRC, @tomthiel said that OEM was sourced from Straightwire (at least for “original” Thiel) but it was never resolved whether my SEs were equipped with that or sourced from FST. It did appear to be 18 ga and twisted per the Thiel recipe.
Note that I also replaced the gold over brass OEM binding posts with Cardas rhodium over silver. On paper, a notable upgrade. I cannot say to what degree the sonics are resulting from the wire versus binding posts. |
Did you use ERSE Fiol/Q for all 3 speakers ? I imagine you mean all three boards? The 2.4 uses a mechanical crossover for the tweeter/mid, so only two boards. The coax and woofer boards each have one coil in the direct feed path and those are the ones Tom selected as targets for foil type. But I’ve read, and now experienced, that caps in the shunt position can have audible consequences even on the woofer board. Some consider better components in shunts to not result in better SQ, all the more so on the woofer. To be fair, the 2.4 crossover is at 700 cycles (IIRC) and, with the low slopes, that woofer is really covering most of the midrange. But, my point is I will not be surprised to read reports of improved SQ using foil type coils in the shunt position. |
@sdecker PM sent
@vair68robert As Tom Thiel wrote just days ago, FST PCBs are on fiberglass. Classic Thiel used point to point connections, with leads mechanically twisted before soldering, on Masonite. That is what I have on my hot-rodded CS2.4.
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They have black MPT capacitors As Tom Thiel wrote, you should post a pic if you want a good answer. Did you mean “MKT”? Those are polyester caps and are likely lower quality than MKP (polypropylene). My FST-sourced OEM boards (China) had CYC brand MKT caps other than a polystyrene 1 uF bypass on the coax shunt (also CYC but, presumably, similar construction to Thiel’s custom polystyrene bypasses). |
That will be interesting, Tom. The markings on that bypass are “PPT” which I misremembered as polystyrene rather than polypropylene.
At this point, I’m inclined to think @marqmike has FST boards rather than Lexington. |
@marqmike It looks like you have an earlier iteration, relative to my SEs, of the FST boards. Your coils are more tightly wound than mine were but otherwise parts quality looks equivalent save the Clarity SAs on the SE coax feeds.
If you are serious about an upgrade, I suggest at a minimum:
1) replace the sandcast resistors with Mills MRA-12s;
2) refresh the 100 uF electrolytics as those caps drift with age (best to replace those outright with metalized polypropylene film caps but 100 uF film caps are expensive and considerably larger than electrolytics to point of likely needing new boards);
3) replace all the polyester caps with polypropylene.
If it was me, I would replace everything including the printed circuit boards except, maybe, 3 of the coils. But I am a crazy person. PM me if you want specific suggestions.
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Those SS-1s would be very appealing if they came with a CS2.4 crossover. I suspect the current bid of $305 is a fraction of the final bid. |
I’m assuming your curiosity is the early numbers were made here in US and later runs were sourced elsewhere? (partly speculative but also based on information from Tom Thiel and my own SEs) The 2.4SE debuted circa 2008. By this time, 2.4 crossovers were outsourced to China. An easy check is to pop out a passive radiator and look for Masonite point-to-point (Lexington built) or fiberglass printed circuit boards (China). Other than the SE prototype(s), it seems all SEs have Chinese crossovers with metalized polyester caps rather than polypropylene. Of course, the coax feed caps are those Clarity SAs which are the real deal (albeit surpassed by ESA, then CSA, and now Tom has announced an even further refined version). Important to note that driver fabrication (and final assembly) for the SEs continued in Lexington. Jim Thiel, IMO, designed some of the very best drivers out there. Surpassed appreciably only by modern stuff like the Vandersteen carbon diaphragms and various “diamond” tweeters. |
@duramax747
what article? Neither enjoythemusic or ultraaudio reviews mentions the SNs. I am really curious to know what boards are in those early units! Those reviews were raves. Did the reviewer’s DUTs have Lexington or FST boards? |
@tomthiel
Thank you for the detailed answer. Interesting observation re: Thiel v Vandersteen house sound.
Those 7 uF PURs are the first I’ve seen in that capacitance value. Will be interesting to see if the North American retailers stock those. In the meantime it looks like @pieper1973 has a lead on getting the 14 and 28 in single caps.
If I ever make any further mods it will probably be to try an ultra bypass (eg, Jupiter copper foil), Path graphite resistors in the coax feed path (really tough to get the correct values at all positions), or, if your reports are over the moon, PUR in the coax feeds. Regardless, I’m sitting on some tricked-out, sweet-sounding CS2.4s.
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Beetlemania may have directly compared coils to coils I did not make this comparison as I replaced all caps and coils at the same time. Not possible, with so many simultaneous changes, to isolate the sonic differences from coils. I spent close to four months elapsed time making changes, allowing burn-in, and making sonic comparisons in mono with the modified and “reference” channel. 1) OEM FST boards (sandcast resistors) to FST with Mills MRAs 2) FST with Mills to Masonite boards with Clarity CSA throughout, Mills, and “Lex” or Erse foil coils, the latter on feed positions (ie, everything different except Mills) 3) New boards with and without Multicap bypasses on coax feeds 4) 160 versus 250V caps on woofer shunts (I heard a difference) 5) OEM hookup wire and binding posts versus Cardas wire and binding posts 6) Single versus biwire from amp I would not lose sleep over unavailability of six nines coils. If you have these in your classic Thiels, great! If you have FST, see if Rob Gillum has “Lex quality” or buy the best you can. I mean, we’re talking about speakers 10-30 years old that were modestly priced to begin with. Sonic improvements from better caps and resistors are notable even if I can’t really speak specifically to coils. That said, IMO, it’s worth putting foil coils in the feed position as these are not expensive. |
@vair68robert
No capacitance, resistance, or inductance values were changed intentionally although my LCR meter measured some small deviations from the target values. That said, OEM caps were mostly 100V whereas the new caps range 160-630V. OEM resistors were 10W, Mills are 12W. I think one, if not both, foil coils in the feed positions were rated different AWG than OEM air cores. And the FST hookup wire appeared to be 18 gauge throughout whereas the Cardas replacements were various combinations of 18 and 15 gauge depending on in/out and coax/woofer.
Tom Thiel cautioned me to check total resistance of the boards. I did not do this before replacing the sandcast resistors but one copy of the layout I have indicates total resistance of the 2.4 coax filter should be, IIRC, 31.6 Ohms and the woofer filter is nearly a flow through. My LCR meter measured resistance, of the final boards, within 0.1 Ohms of those values. |
