Current production Russian and Chinese 2A3 tubes

[Troy Taylor]

Hello-

My Scott AW23 uses a quad of 2A3 tubes in the audio output. Vintage American-made brand NOS replacement tubes are prohibitively expensive to purchase, so I am wondering if anyone has any experience/recommendations with using the new Russian, eastern European, or Chinese made 2A3 tubes now available under the brands of Sovetek, Electro-Harmonix, Shuguang, JJ/Tesla, or any other brands currently produced that I have not listed.

Since tubes are what I consider to be a "consumable" part of the circuit, I am not averse to using modern-production replacements if they are of sufficient quality to be acceptable.  Any advice or suggestions from anyone with experience using currently produced replacements is much appreciated. 

Please note that I accept that any/all of these might not be (or probably are not) as great as vintage originals, but with prices for those being what they are, and the fact that present-day AM broadcasting is not exactly the foremost standard in high fidelity, I am open to compromises that don't endanger destroying original transformers or other components in the event of catastrophic tube failure.  I also don't want to potentially spend $50-$100+ on reproductions that are known to be unreliable or sound terrible even within the limitations of preset-day AM broadcast transmissions.

Thank you and best regards-

Troy Taylor

Edmonds, WA

[mike hadley]

Troy;

So far I have had no problems with Russian tubes, although I have not tried 2a3's.

my aw15 is running on a pair of RCA's

My latest restoration an early Philharmonic has a Russian 6j5 in the local oscillator, a Russian 6h6 in the Expander, Taiwan 6e5 eye tubes and a matched quad of 6p3s that replace the output 6l6's,

the four 6p3s I bought from ebay for less than 20 dollars, matched! they all work like a charm.

And as you say tubes are classed as a consumable,

good luck

Mike

[Thomas Day]

Troy:

My all wave 23 currently has 3 RCA 2A3's and 1 Arcturus 2A3 tubes. I have a set of Sovetek replacements to use when the current set expires.  I purchased these tubes 2 at a time over a period of several years, due to cost.

I have used other types of these tubes in other amplifiers, notably Hammond Leslie and tone cabinet amps. Leslie amps use either 2 5881's or 4 6L6 tubes. The very early Hammond amps also used a quad pair of 2A3 tubes. Later Hammond amps use a quad pair of 6V6 tubes.

They seem to last fairly well.  Since the Scott only gets used for a short time and not every day, the current tubes should be good for years.  I would go for what your pocket book can afford.  Electro Harmonix tubes seem to be good as well. 

[Thomas Day]

Just read thru my last post and need to do a correction Leslie amps use a pair of 6550 output tubes. I just bought a pair to use in the Leslie I have in the living room.  

Thom

[Norman S Braithwaite]

If not rebiased, the Russian 2A3 tubes will draw more current than the traditional American 2A3 tubes putting transformers (power and output) at significant risk of failure especially at our higher than design line voltages.  The bias circuits should be modified to provide 10% more negative bias to avoid the increased risk.

Norman

[Scott Seickel]

I have no experience with the overseas tubes, but you should be able to get good used 2A3's for $50 each. 

It is weird that I checked this forum at least a couple of times since Monday and only now does this thread show.

[Troy Taylor]

Hello and thank you all for the advice. New questions for Norman, based on what you said about current draw.
-Is re-biasing also necessary with the new Chinese-made tubes, or just the Russian-made ones?
-Does operating the radio with a bucking transformer that reduces today's line voltage down to what was originally designed for preclude the need for re-biasing, since it is already dropping the operating voltage by about 10%?
I only use my vintage radios with bucking transformers now, and it really seems to make a difference in how much less hot they get when powered up. I do not not notice any diminished performance either.
Thank you and best regards-

Troy Taylor
Edmonds, WA