300b vs 845

I own a nice 300b amp but would like to know what I might gain/loose going to a 845 tube. I know I will get more watts and therefore more volume or dynamics, but that's really all I know. I have only heard one 845 amp, a ASL Lalya, its sound pretty good, but a little grainy.
Your thoughts would be a big help.
Assuming the amps are of similar quality you will have more power with the 845. All things being equal expect the 845 to be more expensive simply due to the larger chassis and transformers required. The more power you get the more heat the amp will generate; be warned if you live in a hot area and do not have AC.

The ASL stuff is mid fi and average parts and transformers are used. You want to look at quality 300b/845 amps look at Art Audio, Border Patrol, DeHavilland, or custom. You get what you pay for is always true.
Brm1, I would suggest that you contact a manufacturer that makes both 300B and 845 SET amp models and get his/her opinion on where the differences lay. One such person would be Joe Fratus in the USA and owner of Art Audio who makes several 845 models and at least one 300B model too.

The 845 is a bright shining tube, like a 100 watt lightbulb, and runs very hot so these characteristics may be off putting to some. By comparison the 300B is much less bright and hot but both tubes are usually run in pure Class A so expect some heat. Also, the 845 tube is an old radio re/transmisson tube so it doesn't have the frequency range/extension that other tubes have and that is why Gordon the owner of the well respected company Wavelength won't design using the 845 tube, or at least that is what he told me.

Another tube you may want to explore is the great KR Audio PX25 tube that is amazing. Ask Joe at Art Audio about it.
Hope this helps some.
At the risk of generalizing, the 300B can have better frequency range and a more "transparent" midrange. The 845 will outclass the 300B in bass fullness, although in some 845 amp designs, the bass is bloomy and bloated. The 845 was never designed as a wide audioband tube.

In my personal opinion, if you don't need the power, I'd go with the 300B (or 2A3 or 45 even). If you need the power, I would also consider the 211 triode versus the 845.
Another manufacturer making both is Viva from Italy, I use the 845 SET integrated, the Solista. I have heard 300B and I would agree with others opinions, that it may have more "midrange magic", but I feel the 845 is "truer", more accurate across the range and more neutral. I personally love the 845 and would'nt change, but my word, it does run hot. How the Italians manage with their Summers, I have no idea. I am seriously considering a SS integrated for Summer use, perhaps the Lavardin.
In truth, I don't think you can go wrong with either and you won't be rushing back to transistors.
I like them both, and this is the reason I have the Cary M211 Anniversary, it takes 2 845's 2 300B's, 1 6CA7, and 1 ECC35. Truely an amazing amp, Dennis has a winner with this one, IMHO.
I've been through this 300B/845 comparison, trade-offs, etc. to the point of having 300B and 845 amps in my house right now. I have a few months of active back-and-forth experience with both tubes now.

My comments here are informed by the experience of using both amps on highly revealing speakers with 101db/w/m efficiency, so I don't need more power than 300B SET.

I have used a variety of 300B amps and generally they share emotionally-communicative midrange and vocal traits, are articulate with delicate detail in the treble and a lush, euphonic "spray" to the top end. Bass is warm but on most 300B designs is falsely rich due to euphonic harmonic distortion below 80 Hz or so. This can work in favor of small speakers with limited bass range, but is decidedly fat on a full-range speaker.

By contrast, every 845 SET amp I have heard has much firmer bass with superior definition over the 300B SET designs, and it's not just an issue of power difference. Woofer control is better. In the midrange, 845s have the usual SET attributes of intimacy and clarity, but it can't quite equal the 300B's uncanny holography in vocal projection. However, transient impact is discernibly meatier than 300B. On top, the 845 is absent the 300B's "spray" so it does not sound lush, instead it has a more objective, drier presentation. Overall, 300B SET amps and even push-pull versions err on the side of romance and bloom in exchange for maximum realism on human voice and remarkable spaciousness in imaging. 845 SET amps err on the side of astringence and less expansive spatial presentation in exchange for delivering dynamic punch, cleaner bass and more precise locations in the sound stage.

There are many exceptions: First, 845 amps are dramatically affected by your choice of 845 tube. Putting aside the scarce and dear NOS RCA 845, the Chinese 845B sounds dark but full-bodied while the newer 845M metal plate is bright and alive, more like a sparkly 300B. The KR 845 is something else entirely, explosive but a little icy, highly articulate and fast. 300B tube variants have their distinct differences but you have much more variety with less drastic differences available for tuning through tube rolling.

Second, some more exotic 300B designs successfully overcome the tube's euphonic inaccuracies to vault into the first rank of amplification. I have Audion Black Shadow 845 monoblocks, which are the best 845 amps I've heard from any vendor. I use the 845M tube in them, which only amplifies their appeal. The Audion Golden Dream 300B monoblocks, however, are overall a compellingly superior amp, one of the two best amps I've ever heard in over 30 years in the hobby. The Golden Dream has a proprietary circuit to sharply reduce the harmonic distortion and resulting bass bloat common in 300B amps, as well as to distill out most of the false lushness in 300B treble. Midrange is as good as it gets. It is a parallel single-ended 300B topology, using 2 300B tubes per monoblock for 25watts. This amp also has no electrolytic capacitors anywhere, with a silver signal path, silver choke and silver secondary winding on the output transformer. It is 1/3 more expensive than the similarly-designed Black Shadow 845 and its bass is at least as tight and defined, with punch and body rivalling the 845, superior image and locational precision, spellbinding midrange and a top end that is equally objective but not a trace dry.

However, a lesser Audion 300B SET, while excellent in its own right, cannot match the accuracy of its 845 big brother.

Audion amps share common characteristics of fast transient behavior, high articulation, tonal richness and dynamic aliveness. Some 300B designs from other manufacturers are similar, others are syrupy and slow. They make a much less expensive parallel single-ended monoblock 300B amp rated at 18w that has the usual lush 300B signature only a little less so. It's very good. SOME people would prefer it over the 845 amp, but not me.

For now, I own both 300B and 845 amps. I listen to 845 much more than 300B, but then I don't own the Golden Dreams. If I did, 845s would see much less action.

I've heard a few inexpensive 845 amps which sounded comparatively indelicate and ham-handed to me, with otherwise nice bass. On balance, at, say, $2500, a 300B SET is likely to be more satisfying. But somewhere between $3000 and $12,000, an 845 can play to its strengths and be the preferred route to fidelity. And then above that price, it becomes feasible for manufacturers to use a variety of techniques for building to the strengths of the 300B while convincingly addressing its liabilities. At least that's what looks to be the case right now. Chinese amp economics can change the order of things very quickly.

great write-up, Phil! really excellent info, and very well written

I share your impression of the various 845's as played through my Nagra VPA's, though never tried the KR's (some have caused shorts in the Nagra amps, so i'm hesitant).
I am currently own a chinese 845(music angel)..I didnt like it all( too bright/harsh),but i am not sure if it the sound of the 845 tube or the cheap chinese amp that sound harsh.my speaker is the avantgarde uno.

Thanks for you comments. Those Nagra VPA's are great amps, which I'd really love some day to put head-to-head with mine. It wouldn't surprise me if the Nagras would win.

You're right about the KR tube. It is a peculiar beast and in fact I have elected to shun it in my own amps for sustained use. Audion does offer it as an extra-cost upgrade and the factory speaks highly of the tube. I have had zero trouble with the very affordable Shuguang tubes, and the new metal plate is so desirable, even at 25% less power, that I haven't felt any need to spring for hyper-cost tubes, current or NOS. I think the 845M is a breakthrough and I'm really eager to buy a pair of the further upgraded metal plate version that appears imminent from superTNT.

The 845 requires a challenging high-voltage circuit to build which I think explains why some of the entry-level amps sound unmusical when built to a price point. You have the opposite - amps built to a quality point, and I am sure you enjoy them every minute they have glow in their tubes.

Thanks for the very kind words, Phil. I am enjoying the VPA's very much these days. In fact, i will be receiving dsome NOS 12AX7's and E182CC's to drop into these puppies today! I cant wait. Thanks also for the tip on the upcoming SuperTNT 845M. I will be buying them also.
Have any of you folks tried Pearl tube coolers on the 845s?
I concur, thanks to Phil for an excellent summary of his vastly greater valve experience than mine. i have just as it happens, installed the 845B valves in my Solista and am very impressed. I don't know if I would describe it as darker, but the base was the first thing I noticed. The amp audibly goes deeper and I believe the treble is better defined too and with better imaging too. i am tempted by the 845M valves, but I'm told they shine like searchlights and my wife is already muttering darkly about the heat from the Solista. I think anyone taking the plunge needs to take the greater heat with 845 based amps, into consideration, it really makes Summer use problematic.
Excuse me if I bang on about the Viva amps, but they are not as well known as they deserve to be. I believe a review by Art Dudley in Stereophile is imminent.
I meant to make it clearer that the Chinese graphite plate 845s, both the A and B, are darker sounding than the vintage NOS, KR and metal plate variants, which are in turn quite different from each other. If you've never heard anything other than the contemporary Chinese graphite plate 845s, then the 845B sounds as you describe, David. The 845M does light up a room, but I don't experience any more heat output than the 845B. It's just that the glow is more shrouded by the graphite plate configuration. They both get hot but if you've dealt with the heat issues for the B tube, the M will be no worse.

By all accounts the Viva 845 is excellent. I haven't heard it.

Guys, Thanks for the responses. I hadn't thought about the heat issue and that could be a problem the way I am set up. My problem my be my amp and not the 300b tube, I just don't have enough experience with SET.
no heat issue really. the 845 845B and 845M all put out similar heat, and not as much as many. My monos use 4 of them, and the room is not hotter in any appreciable way. The 845M's are brighter (as in more lumens) than the 845 and 845B, but not hotter.
If the power supply design is correct and of adequate capacity heat should not be an issue with a correctly designed 300b. My Audio Note Conqueror was a space heater; my custom 300b tube rectified amp runs warm but does not materially impact the ambient temperature.
My ASL 1009-845 drives avalon opus ceramique with great impact and dynamics in 24 x 14 x10 feet room. It was a surprise as speaker is 87 dB into 4 ohms. I would have cancelled my order of ASL hurricane if i knew ahead of time.
What 845 tube gives the best overall sound?
they're more different than better-worse. What you got now? what you lookin to improve on?
I have a Viva aurora 845 driving Trios using regular chinese tubes. I have had thoughts I would like to try a 2A3 or 45 amp. I know it is less power,only a couple of watts. With the trios it should be enough though. Does anyone have any comments on the comparisons between these tubes and 845. Also, what about cryoed 845. So far I have heard mixed opinions.
I like the 845B tube best. I have tried standard 845's, 845B's, and 845C's. The 845B is clearly superior to the standard 845's. It has a much richer sound with lots of texture. I found the sound of the 845C's too bright for my tastes. The 845C's have more detail and tighter bass, but the sound is a little thin in my amps. On the other hand, the 845B's midrange is very full and pleasing at the expense of the frequency extremes. It kind of reminds me of the WE 300b sound.

Regarding the use of 845B's with a Viva amp. The ones I used on my viva Solista glowed a most attractive cherry red colour before they quite rapidly failed. Presumably the voltage on the Viva is a tad too high.
I have a pair of ASL 845 (AQ1006 mono blocks) driving Bottlehead Straight 8's.
nothing wrong with the ASL's you just got to tweak it. Maybe the chinese are bland but also they seem to last a long time. ASL using regular chinese 845 however i took a different approach, instead of chasing the pricy, exotic 845's, I changed the drivers tubes to a 2 pairs of CBS (1956/1958) 5692, a famed 1952 Sylvania 6SN7 tall boy, and also pulled out the stock chinese 6L6 for a near-NOS GEC KT66 in place. It made it really detailed, the bass is strong, no flab, highs just sweet not too bright or harsh in anyway.

I recall "Jack G" from Audio Ayslum apparently had the intergrated ASL 845 "Layla" he had spend alot of time buying and trying out combinations of various 6SN7s, and liked it alot and it seemed that the old valves' esp the high-end of 6SN7 and KT66 taking place of 6L6's responded very well to the ASL (845) topology.
If I still have my amps and need to replace the 845's I'd liken to try these 845M or 845B the deciding factor would be which i can afford.
a guy in my hometown, an audiophille of more experience than me, come over for a visit, and listen he was godsmacked saying my midrange is insanely detailed he has never heard anything like it.
I forgot to say, that i enjoyed this thread immensely, I learnt alot and one day upon replacement, id get a nice pair of 845B or 845M. I missed audiogon for ages, returning back into music listening after spent much time renovating. Actually i apologise for not staying on topic as per subject of the 845 tubes (valves), just noting that sometimes you can get good result on a budget with smaller, less costly NOS tubes thats are drivers if not 'output valves'. but i guess chances are that if a better 845 tube the overall result would be ever better.

Grummer, I've ordered a pair of the new (vertical) versions of the AQ1006s, so your comments are VERY interesting. Other than tubes, are your amps still original...caps, resistors, etc? I've been thru the schematic for the just-superceded version, and it's ripe for improvement, as someone above said. The almost-1000VDC output-stage power supply presents problems for replacement caps; I believe I'll be using 500V. Panasonic TS-UPs in the 1st pole and a 51/1500 Solen metallized 'propylene in the 2nd. I really like the idea of this amp's tube-regulated front-end powersupply. The rest of the amp is pretty standard in what it will get for parts upgrades. I have hand-written notes and a notated schematic that I'll e-mail to anyone who asks--jeffreybehr(at)cox(dot)net.

Have you tried the more-generic Shuguang 845 tube v. the ValveArt 845 and noticed any differences? The former are a little less expensive, but the latter can be bought in matched pairs, FWTW in mono-SETs, for $80/pr. from Advantage Tube Services in FL.
Jeffreybehr, no i havent tried the more-generic Shuguang 845 tube v. the ValveArt 845, still running the stock ASL845 tubes. I have no spare 845's so obviously, I would need to read alot these varients. Similar to what you may be saying (correct me if im wrong), sometimes plainer varients can win over because the synergy of the system hold it together better than fall apart in vain with excess open-ness. It doesnt matter of the most exotic is hailed about the most, It's how it would 'open up' or 'enrich the details' or even 'flow it out better' depending on what it is lacking or got too much of in audiabily sense. it will be quite a while before i get to this point :)

Isn't the Valve Art 845 just a rebranded Shuguang? The dealer told me this when I bought my 845Bs. I am curious because I may buy a spare set of 845Bs in the near future, and I want to make sure that I get the Valve Arts if they are different from the Shuguangs.
Jeffreyds ,
i have came across some sites which are reviews of some of these chinese valves,
and take note of appearance, descriptions, even use google image search or just plain google try trace if any pictures compares, you would know if the source (net or dealer) is accurate or not.



hope these helps

im not even sure, but getting there in terms of gathering information, it wont be till well into 2007 i'd get either 845B or 845M or even a NOS... will let you know

I agree with you about upgrading the caps, chokes and windings for the ASL, however , im not experienced enough to do this myself but has a small fortune to know a retired army engineer who does, ONLY if it does breaks down, id replace if i have to (thin wallet now).

The valve art is just a rebranded Shuguang. Valve ART claims that are built to better tolances for them. I bought some. Didn't A-B very much time though. AS I don't think there was any difference. One out of the three pairs I ordered, one was cryoed and failed after a couple of weeks before I could compare to the non cryoed.

Valve Art doesn't charge much more their's. I think the name looks better anyway than Shuguang. But don't waste too much time thinking about this.
Yes, the ValveArt 845 is made by Shuguang, but I understand they're selected to tighter tolerances. I've accumulated a pair of each while I wait...and wait...and wait...for the (new-version) amps.

Just so we all understand, the 6L6 is the series-pass device in the tubed PowerSupply regulator for the 2-'N7 frontend; the 'N7 close to it is the regulator's error amplifier. One of the things I really like about this amp is that its frontend PS is separate (after the power transformer's primary windings) from its output-stage PS. Each of the other 2 'N7s is a Voltage-gain stage and a shunt-regulated push-pull (SRPP) stage suppling the Voltage. (For details on the latter, see http://db.audioasylum.com/cgi/m.mpl?forum=tubediy&n=108914&highlight=jeffreybehr&r=&session= .)