Hey guys!
I've been around this forum for a few weeks, having got interested in a good sounded 2A3 pair for my SET.
The choice is: 2A3C Mono plate Shuguang Or 2A3 Monoplate Sovtek.
I would like to know which 2A3 would you propose?
Does anyone have experiences with this tubes?
Thanks for the advice!
I've been around this forum for a few weeks, having got interested in a good sounded 2A3 pair for my SET.
The choice is: 2A3C Mono plate Shuguang Or 2A3 Monoplate Sovtek.
I would like to know which 2A3 would you propose?
Does anyone have experiences with this tubes?
Thanks for the advice!
I've both of them, Shuguang is big bulky tube, but contrary has a pretty light sound as some would expect by its size,very detailed; Sovtek is a nice sounding tube, especially for the price is a bargain. Sound is solid, with nice mids, and "warm" sounding in comparision with Chinese tube. RCA is hard to compare with previous tubes, but for the price I would rather choose Sovtek. Try also EH. Driver tube is also very important for the overal sound of the amplifier.😉
Another option might be the JJ version of the 2A3 which is basically a 300B with 2.5V filaments.
I've used the Sovtek 2A3 monoplate and while not quite a match for a good set of Kenrad dual box plate 2A3 it is surprisingly good for the money.
If you can afford it a pair of Kenrad box plate 2A3 off of eBay would be my first choice. (Black internal coated glass 1940's vintage)
I've used the Sovtek 2A3 monoplate and while not quite a match for a good set of Kenrad dual box plate 2A3 it is surprisingly good for the money.
If you can afford it a pair of Kenrad box plate 2A3 off of eBay would be my first choice. (Black internal coated glass 1940's vintage)
@levelfive, as I recognize properly a flag of your country, you live in tubes Mecca, Russia. When you walk around fleemarkets, if you notice smal, fat glass bottle with markings 2C4C Svetlana, catch it quickly. This tube is fantastic, practicaly equal to a NOS american tubes. If you found another pair please, notice me and I will destroy tham in my pair of UX4 sockets...
robot said:
Ok, interesting.
What i found on audiokarma forum:
PS: about fleemarkets here. a big chance to buy junk (at one's own risk) and the gain in price is not too big. I preffer the matched pair from German/UK/US onlineshop, so that to save the time and money 😉
The NOS 2C4C Svetlana is very hard to find here.
The Kenrads generally go for less than the RCA 2A3 and I prefer them, however I don't know whether or not they would be affordable.
I have heard good things about the Svetlana 2C4C, and IIRC might have heard a pair at one point. They aren't very easy to find anywhere I guess.
Pretty much the same at flea markets here, however at radio shows good bargains are still to be had if you get there early and look carefully. You don't have any radio collectors clubs in Russia that sponsor such shows?
I have heard good things about the Svetlana 2C4C, and IIRC might have heard a pair at one point. They aren't very easy to find anywhere I guess.
Pretty much the same at flea markets here, however at radio shows good bargains are still to be had if you get there early and look carefully. You don't have any radio collectors clubs in Russia that sponsor such shows?
I was in contact with a guy from St.Petersburg about those Svetlanas, but he told me that they re practicalu extinct, but I m not sure. Today in Russia and in former Eastern block states are plenty of nos Russian tubes, and they can be purchased for a reasonably amount of money. Problems with those tubes is that they vary in quality, they sometimes have problems with sockets etc.
I have about 10 6n8s but I m really satisfied only with a pair of black base reflector tubes from '61, and a pair from '74. Widowmaker in one older post wanted 2a3 Sovteks from summer production
, I presume he knows some secret information about assembling lines in Sovtek factory 😀 . I read somewhere on the net that the Sovtecs had a selected series, but I m not sure what it mean.
I agree that the best 2a3 tubes are Tungsols and Kenrads, maybe also Fivre, RCA and nos Svetlana but i'm not ready to pay some 400 bucks for a single tube or a pair, becouse my amplifier is runin' hot every day for at least a 4-8 hours, and a sound superiority of those tubes aren t justifing the differeties in a price.
Shuguang 2a3c is essentialy 300B runnin' on 2,5V and have a lot of similarities with a sound of that tube, I bought tham from Tubedoctor for 45€ a piece, I put tham in sockets of my amp rarely becouse they are too bright for my taste. Shuguang is a huge, hungry beast definitelly, and draws more current and produces more power than ordinary 2a3.
I have about 10 6n8s but I m really satisfied only with a pair of black base reflector tubes from '61, and a pair from '74. Widowmaker in one older post wanted 2a3 Sovteks from summer production
, I presume he knows some secret information about assembling lines in Sovtek factory 😀 . I read somewhere on the net that the Sovtecs had a selected series, but I m not sure what it mean.I agree that the best 2a3 tubes are Tungsols and Kenrads, maybe also Fivre, RCA and nos Svetlana but i'm not ready to pay some 400 bucks for a single tube or a pair, becouse my amplifier is runin' hot every day for at least a 4-8 hours, and a sound superiority of those tubes aren t justifing the differeties in a price.
Shuguang 2a3c is essentialy 300B runnin' on 2,5V and have a lot of similarities with a sound of that tube, I bought tham from Tubedoctor for 45€ a piece, I put tham in sockets of my amp rarely becouse they are too bright for my taste. Shuguang is a huge, hungry beast definitelly, and draws more current and produces more power than ordinary 2a3.
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robot said:
Understand. I like 300B sound (was listen on Triode TRV A300SE 300B via Klipsh acoustic) and will order Shuguang, if crisis afford it me.
Thanks for a lot long posting!
I just put together a little 2A3 powered amp and I used a set of the Sovteks from New Sensor. I didn't get the chance to audition a bunch of different tubes or anything so I can't offer a comparison. I can say that the amp sounds really nice and the tubes have caused no problems. The amp has been together for a little over a week so time will tell how long they will last but they seem to be quite nicely built.
I've always been curious, is the stuff sold by New Sensor as Sovtek, Genelex and other brands available in Russia or are they strictly made for export? Are there domestic versions of say the KT-66 or 2A3 that are available there in Moscow?
I've always been curious, is the stuff sold by New Sensor as Sovtek, Genelex and other brands available in Russia or are they strictly made for export? Are there domestic versions of say the KT-66 or 2A3 that are available there in Moscow?
DaveMcLain said:
Dave, thanks for your experience!
About Sovtek and 2A3.
Sovtek is New Sensor and New Sensor is Sovtek. Company owned by M.Matthews http://en.wikipedia.org/wiki/Sovtek
Sovtek, EX & other brands are available here, but the chance to buy scrapping is more higher. For US & European shops tubes are matched by manufacturing.
When looking at NOS 2A3 tubes, the brand is not always meaningful due to the fact that many manufacturers provided tubes to each other to prevent changing the line out as often. I've actually got a NOS pair of RCA 45 in original boxes and identical date codes on the bases... problem is, one is a genuine RCA (you can tell by the internal construction) and the other is a Sylvania. The same applies to the 2A3 as well. So, rather than specifying a certain brand I always specify a specific internal construction.
From I've seen over the years there are quite a few variations done over time. The original 2A3 is a single-plate in ST glass... has a center-tapped filament which consists of 8 runs (wired in a left side and right side in parallel). While most people rave about these, they are quite sensitive to mechanical vibration and are impossible to get quiet operation without DC on the filament. You can find these is many brands... RCA, Sylvania, Philco, etc. and they generally command very high prices, I've seen prices up to $960 paid for a NOS pair in original boxes.
Beyond this, you have the cost-reduced dual versions. There are the true dual box plate versions the other Kevin noted, and then there are the more common dual versions which have a single plate assembly with dual filaments and grids wired in parallel. Next is the internal construction differences. The more common RCAs are available in Black plate and Gray plate... with the Black plate version generally fetching higher prices but not necessarily better performance.
What is more important is how the internal construction is done. I've seen 3 variations of filament support, earlier dual-plate versions had two small coil springs on the top insulator (per filament section) and later ones had what I refer to as the "fishing rod" supports, again two per filament section. The later RCA dual-plate versions have fixed tension and only a simple wire laying flat against the top mica insulator with filament looped over it twice to form the "M". Other differences are how the the top insulators are tensioned against the glass envelope, either additional mica supports perpendicular to the top mica (ala RCA) or in some cases with spring wire thru the top mica horizontally. You can also find most of the "fishing rod" versions have much more robust plate structures with an additional vertical support wire and is riveted to the mica insulators.
I've got quite a collection of all of the above and have done much testing over the years (yea, I'm probably older than some folks out here)... but, here's some personal views on what I think are a relative pecking order.
1- Single-Plate 2A3s are nice... provided you have a clean DC supply and some isolation. Problem is the filament wires are much longer than the dual-plate versions and with 8 runs, they tend to get excited easily as there are only two coil springs to provide the tension. Still, being a true single triode, they don't suffer from the interaction of two triodes in parallel.
2- The true dual box plate ones Kevin described earlier are excellent and usually very well supported internally, but as he noted somewhat rare and in many cases are sleepers as many assume the RCA is the only worthy acquisition.
2- The "fishing rod" supported filaments with the riveted support wires to the mica insulators are next IMHO followed by the same using the coil springs, the latter not being quite as immune to mechanical influence. If you can find good pairs of either, these are probably preferred overall due to reasonable cost (versus the single-plate) and the fact that you can get really quiet ones with AC filaments.
3- The most common of the RCA ones described above are last in my book, but the black plate versions are probably a bit better, but in any case, not worth the price they command... the other internal construction types are better.
I would also note I've seen some clones of the above (#3 RCA) done very poorly and are pretty bad... lots of gas, funky patterns in bluish-green on the top mica, higher distortion and poor sound quality.... the plates also look funky.
Sorry for the long rambling, but don't go by marked brand alone.... it doesn't always mean you have that particular brand. Best to find the more robust internal construction and try to find a nice matched pair with the same brand and date codes marked on the base. Overall I think you can find better ones at better prices this way.... of course, just my $0.02.
Regards, KM
From I've seen over the years there are quite a few variations done over time. The original 2A3 is a single-plate in ST glass... has a center-tapped filament which consists of 8 runs (wired in a left side and right side in parallel). While most people rave about these, they are quite sensitive to mechanical vibration and are impossible to get quiet operation without DC on the filament. You can find these is many brands... RCA, Sylvania, Philco, etc. and they generally command very high prices, I've seen prices up to $960 paid for a NOS pair in original boxes.
Beyond this, you have the cost-reduced dual versions. There are the true dual box plate versions the other Kevin noted, and then there are the more common dual versions which have a single plate assembly with dual filaments and grids wired in parallel. Next is the internal construction differences. The more common RCAs are available in Black plate and Gray plate... with the Black plate version generally fetching higher prices but not necessarily better performance.
What is more important is how the internal construction is done. I've seen 3 variations of filament support, earlier dual-plate versions had two small coil springs on the top insulator (per filament section) and later ones had what I refer to as the "fishing rod" supports, again two per filament section. The later RCA dual-plate versions have fixed tension and only a simple wire laying flat against the top mica insulator with filament looped over it twice to form the "M". Other differences are how the the top insulators are tensioned against the glass envelope, either additional mica supports perpendicular to the top mica (ala RCA) or in some cases with spring wire thru the top mica horizontally. You can also find most of the "fishing rod" versions have much more robust plate structures with an additional vertical support wire and is riveted to the mica insulators.
I've got quite a collection of all of the above and have done much testing over the years (yea, I'm probably older than some folks out here)... but, here's some personal views on what I think are a relative pecking order.
1- Single-Plate 2A3s are nice... provided you have a clean DC supply and some isolation. Problem is the filament wires are much longer than the dual-plate versions and with 8 runs, they tend to get excited easily as there are only two coil springs to provide the tension. Still, being a true single triode, they don't suffer from the interaction of two triodes in parallel.
2- The true dual box plate ones Kevin described earlier are excellent and usually very well supported internally, but as he noted somewhat rare and in many cases are sleepers as many assume the RCA is the only worthy acquisition.
2- The "fishing rod" supported filaments with the riveted support wires to the mica insulators are next IMHO followed by the same using the coil springs, the latter not being quite as immune to mechanical influence. If you can find good pairs of either, these are probably preferred overall due to reasonable cost (versus the single-plate) and the fact that you can get really quiet ones with AC filaments.
3- The most common of the RCA ones described above are last in my book, but the black plate versions are probably a bit better, but in any case, not worth the price they command... the other internal construction types are better.
I would also note I've seen some clones of the above (#3 RCA) done very poorly and are pretty bad... lots of gas, funky patterns in bluish-green on the top mica, higher distortion and poor sound quality.... the plates also look funky.
Sorry for the long rambling, but don't go by marked brand alone.... it doesn't always mean you have that particular brand. Best to find the more robust internal construction and try to find a nice matched pair with the same brand and date codes marked on the base. Overall I think you can find better ones at better prices this way.... of course, just my $0.02.
Regards, KM
Dear, KM!
Thank you for learning the basics (without sarcasm!).
But i hear no words about subj (monoplate: Shuguang Or Sovtek?),
which sounded better (less distortion, less hum, etc.).
Sorry, with all due respect, internal construction variations can be detected only (commonly) after payment 😉
Thank you for learning the basics (without sarcasm!).
But i hear no words about subj (monoplate: Shuguang Or Sovtek?),
which sounded better (less distortion, less hum, etc.).
Sorry, with all due respect, internal construction variations can be detected only (commonly) after payment 😉
Hi levelfive,
True... can be tough to figure out what you bought until after the fact... in the case of either ebay or audiogon, you can usually tell by the pics they post, at least if they're good ones. Still you never really know the quality of your purchase until they arrive and you plug them in.
I always match my own sets of tubes for SET amps as my designs have no feedback. I match an entire set (rectifier, input/driver and output) for (power supply) voltage, stage and overall gain, distortion, hum and noise. Unless you do this it's very unlikely you will have both amplifiers (or channels) performing the same.
I don't have any experience with the new manufactured 2A3 tubes... have ample stock of NOS so I don't need to obtain new ones... wish I could be of more help there.
If you're using an AC filament drive, you might want to try my split balance technique. This has been quite effective in lowering output hum on the output tube. It's quite simple actually. I use a center-tapped filament transformer for a 45 or 2A3. I use the center-tap for the cathode bias resistor and essentially have a fixed DC balance to ground as the filament transformer winding is very low DC resistance. The AC balance is adjustable. I use a wirewound 100-ohm potentiometer in parallel with the filament and place the bypass capacitor from the wiper to ground. Also, be sure to pad the pot with a pair of 12 ohm resistors, one from each end to the wiper. With good 45 tubes, output hum/noise can be better than 85dB below 1-watt, i.e., 125 microvolts into 8-ohms. Most 2A3 tubes won't do this well due to the dual filament but I've got many pairs that will do 80dB s/n.
Regards, KM
True... can be tough to figure out what you bought until after the fact... in the case of either ebay or audiogon, you can usually tell by the pics they post, at least if they're good ones. Still you never really know the quality of your purchase until they arrive and you plug them in.
I always match my own sets of tubes for SET amps as my designs have no feedback. I match an entire set (rectifier, input/driver and output) for (power supply) voltage, stage and overall gain, distortion, hum and noise. Unless you do this it's very unlikely you will have both amplifiers (or channels) performing the same.
I don't have any experience with the new manufactured 2A3 tubes... have ample stock of NOS so I don't need to obtain new ones... wish I could be of more help there.
If you're using an AC filament drive, you might want to try my split balance technique. This has been quite effective in lowering output hum on the output tube. It's quite simple actually. I use a center-tapped filament transformer for a 45 or 2A3. I use the center-tap for the cathode bias resistor and essentially have a fixed DC balance to ground as the filament transformer winding is very low DC resistance. The AC balance is adjustable. I use a wirewound 100-ohm potentiometer in parallel with the filament and place the bypass capacitor from the wiper to ground. Also, be sure to pad the pot with a pair of 12 ohm resistors, one from each end to the wiper. With good 45 tubes, output hum/noise can be better than 85dB below 1-watt, i.e., 125 microvolts into 8-ohms. Most 2A3 tubes won't do this well due to the dual filament but I've got many pairs that will do 80dB s/n.
Regards, KM
@kmaier, lucky guy 😀 you probably bought your stock of 2a3's when they were sold cheap, before the Japanese triode invasion, and a triode revival. How things are going, rare tubes would be sold at jewellery shops, or at Sotheby s auctions with a paintings of Van Gogh.
Acually your methodeof hum cancelling is old but very effective, I use it also, and my driver tubes are also on ac, with a pair of resistors to ground at the end of fillament wires. Also I use solid piece of silver wire for common ground, solid metal box for amplifier, and hum can be heard approximately one feet from the loudspeaker, no matter if i use Valve art biplate or Sovtec monoplate tube. I noticed actually what really changes the sound of amplifier is a choice of a driver tube (6sn7 in my case), and after that a choice of output tube. I have "classic" 2a3 (two 6sl7 on highgain, 6sn7 driver of power tubes), SS rectification, choke, and with a good combination of driver tubes, final sound coud be altered from dull (jan philips) to bright and analitic (russian tubes) so I combine it to get Rock, Jazzy or Ambient sound 😉)).
Reason is probably becouse different brands of tubes had different working points and driving capabilities, which changes overall sound slightly but noticeably. Anyway, combining modern output tubes with old driver tubes, could produce interesting sound, and a lot of experiment is necessary to produce the holy grail of high fidelity sound.
Acually your methodeof hum cancelling is old but very effective, I use it also, and my driver tubes are also on ac, with a pair of resistors to ground at the end of fillament wires. Also I use solid piece of silver wire for common ground, solid metal box for amplifier, and hum can be heard approximately one feet from the loudspeaker, no matter if i use Valve art biplate or Sovtec monoplate tube. I noticed actually what really changes the sound of amplifier is a choice of a driver tube (6sn7 in my case), and after that a choice of output tube. I have "classic" 2a3 (two 6sl7 on highgain, 6sn7 driver of power tubes), SS rectification, choke, and with a good combination of driver tubes, final sound coud be altered from dull (jan philips) to bright and analitic (russian tubes) so I combine it to get Rock, Jazzy or Ambient sound 😉)).
Reason is probably becouse different brands of tubes had different working points and driving capabilities, which changes overall sound slightly but noticeably. Anyway, combining modern output tubes with old driver tubes, could produce interesting sound, and a lot of experiment is necessary to produce the holy grail of high fidelity sound.
One of these days I would like to try the Shuguang 2A3's in my amp just to see how they compare to the Sovtek's that I have now. Really just because I've had some nice results with the Shuguang tubes in other amps for guitar use. Their "Coke bottle" 6L6 is really cool in a Fender Tweed Bassman and the KT-66 sold through Valve Art is also excellent and reliable.
For me I didn't find the Shuguang 2A3 readily available for a good price so I went with the Sovteks since I buy supplies from New Sensor quite regularly. I looked for 2A3's at Antique Electronic Supply and I think the only current production they had were the JJ's which were pretty expensive for this project.
For me I didn't find the Shuguang 2A3 readily available for a good price so I went with the Sovteks since I buy supplies from New Sensor quite regularly. I looked for 2A3's at Antique Electronic Supply and I think the only current production they had were the JJ's which were pretty expensive for this project.
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