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Model: | 845B |
Category: | Tubes |
Suggested Retail Price: | $150/pr |
Description: | New 845B from Shuguang/SuperTNT |
Manufacturer URL: | Shuguang / SuperTNT |
Review by Ed Sawyer (A) on June 23, 2004 at 10:24:54 IP Address: 24.62.250.187 | Add Your Review for the 845B |
The new 845BThis review covers the new 845B tube, from Shuguang in China, and distributed by SuperTNT.com. Serial numbers for the pair in this review are 0005 and 0006, the first two in the USA, as far as I know. Retail price is $150 USD per pair, direct from SuperTNT in China. I do not believe they have a USA based distributor yet.
The 845B is a recent development by Shuguang, and structurally it is a very close copy of the 1940's vintage Amperex brass base 845. It has a graphite plate (like all 845s since the 1930s), and a beautiful copper base. Pins appear to be nickel-plated brass. Like the Amperex, it has no top mica connecting the plate structure to the glass envelope. (current production 845s from China, Kron and Cetron all have top micas which couple the plate structure to the glass). These 845B have full 845 dissipation ratings and 1250v plate rating and as far as I can tell are compatible with any 845 amplifier application. Like all 845s except Kron, these have Thoriated Tungsten filaments, which glow brightly. It has two ring getter halos at the base of the tube.
(Click any image for a larger version)
Packaging The packaging supplied with these is the best 845 packaging I have seen - quite robust, with a nested clamshell box made from high-density mat board, and an inner 2-piece foam cushion and foam wrapper. Despite the outer box being a good bit beat up from it's trip from China (via DHL), these tubes survived fine with no damage - an impressive feat in itself.
The Packaging
Nicely made boxes
Electrical Tests Running these tubes on my curve tracer setup shows traces which are well matched and clearly well within specs, as compared to other (vintage Amperex) 845s. The curve tracer, A Systron-Donner 6200B, runs up to 1000v on the plate and negative grid steps from 0v to -100v on the grid. In both cases, the tubes had curves which were textbook accurate, even at the top and bottom. Electrically, they are perfect, as one would expect from new production tubes. Quality control on this aspect has no problems at all. They biased up fine in my amplifiers. Running on AC filaments, they required some adjustment of the filament hum pot. With adjustment, residual hum was the same as other 845s I have been running, and a non-issue. Running on DC filaments of course there were no problems, with zero AC hum.
Curves, tube # 0005
Curves, tube # 0005
Curves, vintage Amperex 845 brass base
Sound I ran these in my Electronluv 45-845 amps, for several days. I compared to other 845s concurrently (one 845B in one amp, and another 845 in the other amp), and also comparing the tubes in pairs. Other amps included Antique Sound Lab AQ 1006-845, which were used but not as extensively. The Electronluv amps run these tubes in the 80-90% dissipation range, a nice high voltage sweet spot without over stressing the tubes by running them at max dissipation. Output power is about 18-20w, using a SET Parafeed topology.
The 845B is a great sounding tube. Very close to the sound of NOS 845s, and definitely better than the well known regular Chinese 845. The highs are slightly less sibilant than a Cetron 845 (a tube which tends towards a touch of brightness - good for systems that are a little dark). The upper mids, in the female vocal range, are nicely rich without being overly warm. In comparison to Cetron and the other chinese 845, the 845B is more harmonically pleasing in this range. Bass is the equal of any other 845 I tried. They are as non microphonic as any other 845 I have. (due to low gain, 845s in general are not microphonic to any noticeable degree, even with abuse like tapping the tube while in operation).
845B in operation
845B in operation, another viewConclusion
Do NOS vintage tubes sound better? Well, yes - as expected. The difference however, is slight - the 845B comes closer than the regular Chinese 845 by a fair margin. Even in back to back comparisons, one has to listen closely to discern differences between vintage 845s and the 845B. In casual listening, it's so close as to be of little concern. The vintage NOS tubes are a bit better (cleaner, a bit more extended, slightly better harmonically and somewhat more musical), but considering the difficulty and cost to acquire them, the 845B is a more logical choice for all but the most discerning and well-heeled 845 user and collector. I'd have no problem recommending the 845B to anyone who uses 845s. No matter how high resolution the system, these 845B tubes will not disappoint sonically, based on my experience with them. These are far and away the best tube made in China that I have seen and heard, and the only Chinese tube I'd use in my own equipment.
The future: A metal plate 845?
SuperTNT has said they will be developing a metal-plate variety (845M), hopefully to debut in August of 2004. I eagerly await these, hopefully they will work out as planned. Metal-plate vintage 845s are quite rare, and finding good ones which test and work as they should is rarer still. Many people consider a metal plate 845 as the holy grail of 845s - it will be interesting to see how things develop from Shuguang and SuperTNT on this front. A reasonably priced, metal plate 845 that worked well and sounds great, would be a nearly untoppable coup in the world of 845s.
Product Weakness: | Not quite as good as NOS/vintage 845s, but differences are minor. Would be nice if base was polished/clearcoated. No USA distributor (yet?) |
Product Strengths: | Nice build quality and sound, reasonably priced, the best value current production 845 made today. |
Associated Equipment for this Review: | |
Amplifier: | Electronluv 45-845 monoblocks |
Preamplifier (or None if Integrated): | Electronluv AV20/801 |
Sources (CDP/Turntable): | SCD-1 |
Speakers: | Martin Logan CLS |
Cables/Interconnects: | Cardas Neutral Reference |
Music Used (Genre/Selections): | various |
Time Period/Length of Audition: | 2 weeks so far |
Other (Power Conditioner etc.): | Equitech 2Q with OFC toroid |
Type of Audition/Review: | Product Owner |
Follow Ups:
EdYou did not mention your operating point for the 845 in the Electroluv amp. Can you please enlighten us as too the high voltage "sweet spot". Thanks in advance.
Hi Ed,Got in 10pairs for an amp. manufacturer and still waiting for the results, but if what you say is true, I have no fear as to the results.
That's nice! Hopefully, that sort of quality will find its way into other types currently in production.BTW, if they can make an 845 that good, they should be able to produce a 211 of equivalent quality. AFAIK, the only difference between the 2 types is the grid helix.
Eli D.
I know that Dave Slagle likes Copper GM70's, but I have metal plate 212's and various graphite plate versions/equivalents.The metal plate comes second to one particular graphite version (AR300) by a large margine. It is better than all the other graphite's overall, but does have some shortcomings (slight lack of focus the main one).
It will be interesting to see how the metal plate 845M turns out. I have a hunch that poor construction quality would stand out more.
I have now tried the Russian graphite GM70 and prefer it to the original Chinease 845 before they sorted out the support rod problems. Haven't had an opportunity to try copper yet. GM70 is of course a much better price.
Reads confusing.It is the metal plate 212 which has shortcomings not the Australian Graphite plate, which is audio Nirvana.
Considering the price of 212's this information may not be much practical use but it's good to know some benchmarks.
hi Paul -So, do you like Aust. graphite 212, then a metal plate version, then the rest of the graphite ones? Interesting the metal plate one is second to the Aust. graphite plate ones. (those are super sweet and minty NOS, so probably hard to find metal plate ones as good condition, I'd think)
GM70 - yeah, cheaper. But cheaper is cheaper. Wish they looked better - I find the overall aesthetic on those pretty lacking, aside from internal copper coating on the plate glowing with reflected filament glow. Also, aren't GM70s no longer made? I am sure there are large stocks, but it's nice to have a tube that is in current production (just for peace of mind mostly).
according to another member on the gm70 list, they are still being produced...a rumour ofcourse, but possible.
Yes that's the order. The AR300 is the favourite but as an equivalent it goes about the process in a completely different way. It doesn't look anything like the various 4212's.The metal plate versions I have are all nos Royal Air Force from David Crittle, I thinkl the suffix is D, they sound softer and more three dimensional than the E and H suffix, but slightly lacking in focus. The AR300 focuses things right up and has the most natural sound.
Paul, 4212D is oxide coated according to STC datasheets.
Oh shucks I'll have to get one out of the box and have a look. Yes you're right, these are 4212E. The rest that I have are 4212H and V1505 which has an identical structure to my 4212H's but a larger glass envelope. It sounds better for the larger envelope, don't ask me why. The 4212E's have similarly large envelope, but with the important addition of an inverted glass pip at the top which assists in rigidity of the structure like the best and most rare 845's. The AR300 is a little longer than the V1505, and has a completely different internal structure and colour of anode material (more black than grey).I do have an oxide coated version but it whizz banged and popped the first time I tried it. The unscrupulous eBay seller washed his hands of it.
Paul,damn curious how that AR300 look like. Would you send some pics or post them somewhere?
When I got them out to photograph for you I realise my error, my AR300's are Canadian not Australian. The memory plays tricks with us.What my neighbours don't appreciate is my garden is a natural meadow.
The index page
http://myweb.tiscali.co.uk/paulbarker/
Shows all the types I presently have. Darren Dean has a few other versions if he still has them, I know he was selling some a short while ago.
The AR300A on the left has the largest envelope. Actually size of envelop correlates to sound. The little squirt on the right is the worst of the bunch. I'd still accept a pair with open arms!
Thanks Paul! Which STC is from David from Oz?
2nd from the left. It is quite different to the other one (with the dirty pins). Only Crittle's has the inverted glass pip for support. On the other one Anode is set at a different hight and braced differently to make up for the lack of glass inversion. I wish I could give you a sound comparrison but this one has gone soft.I'm just hooking up a test amp in which I can compare gm70 to 212. A friend is coming over on Saturday to do the evaluation with me.
I'll be using the same James transformers on 5k for GM70 and 7k for 212.
I have copper GM70's as well as the other type (is it really made of graphite?).
Won't it be interesting if the copper gm70 is up there with the 212's?
Paul,Have been waiting till Chris V finishes his 212E amp to ask him for the same test, but looks like you are faster. My own project is GM70/304tl based but I make everything ready for 212 as well. Why not the same 7k for both tubes and equlaizing the power by volume control? I'd go for 10k after few nights spent over the STC curves.
Yes, the other GM70 is graphite. For Cu ones decrease the max power to 100W.
Yes Chris and I sometimes get together.I'll be waitning with baited breath for the result also.
Do you go to the GM70 Yahoo group? Probably the best place to put up the review.
Yes, waiting for the rev. there, Paul! Consider putting the same high load for gm70 as well, or better yet try both tubes with both 7k and 5k - would be even more interesting! Don't forget to describe the schematic!
OK I'll do that and as you are on GM70 forum I'll continue over there.
Hi Ed,Thanks for the informative and interesting review. It was thorough, clear, useful, and the photos were very nice. :D
Best Regards,
Things are looking up for 845 amp owners.How's that new ElectronLuv pre-amp sounding?
it's the best, really. AV20 meshplate rules! Will post some pics and such of it soon, for those who have not seen it yet (unlike yourself. ;-)
Nice review Ed!
LOL! Oh, from a good friend who has an even more impressive collection of tubes and stuff than me. ;-)It looks sharp now, you would not recognize it probably... fully cleaned (in an anal way - toothbrush, et al), polished the chrome ends of the knobs, respray painted the top and bottom panels (plus floated out the dents in them)... it cleaned up great! Thanks again on that. Not having a huge loft of gear, I can lavish such attention on the few pieces of test equipment that I DO have. ;-)
nothing here
How's the 845 amps drive the ML electrostatic low z treble without puking?How's the 845 amps sound with good horns?
Thanks,
Magnetar
hi Magnetar,I have the first generation CLS which are not as bad a load as the later versions. I've driven them off a Gaincard before, with good results too... These amps (845s) have robust power supplies, they seem to have no trouble driving anything I have. They don't have a ton of gain, so the preamp needs some (which it does).
I am still finishing up my 4-5 way horn system, so I can tell you about that later (845s with horns). I am sure it would rock the house!
.
Ed -
Any comments on how they compare to the KR 845?
Thanks.
You know, those are one of the only type of 845 that I *don't* have. I have thought about getting some and talked to E. Kron about it @ CES last year...The thing that concerns me though is the KR 845 I believe only draws about 1.25A of current (Vs. 3.25A for a normal 845 filament)... so in an unregulated supply, that means about 14+v for the fil. vs the 10v that it is specified for. I have yet to see or read about that issue being addressed and what the solution is (if any). So, that is mainly why I have held off on the KR 845. (it has a metal plate which is cool, but the filament issue, plus the price, have kept me for bothering with it thus far.)
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