GoodSoundClub - Romy the Cat's Audio Site

In the Forum: Melquiades Amplifier
In the Thread: Single-stage Melquiades vs. DHT amps

Post Subject: A picture is worth a thousand micromhos?Posted by floobydust on: 1/26/2009

Yes, the last 3 pics are of the "dead" 2A3. Saying it warms up could mean two things... it literally gets warm and nothing else as it may have leaked air. Or it could mean the filament lights up (and assumes getter flashing still intact which is hard to tell from the pic). If it's the latter, it could be nothing more than a bad solder connection to the base for the anode... or a mechanical break internally. Either way, at least it was claimed as bad.

I have a few pairs of the Sylvania 2A3s.... one has the coil springs and engraved bases (which are the really old ones) and another pair with the fishing rod supports and printed bases. Both of these are very good 2A3 internal construction. I'm not really biased towards coil springs or fishing rods... they both perform very well. I have seen a couple where one of the coil springs broke loose... bad luck, tube is worthless afterwards.

If you manage to pick up a pair of the real Sylvania 2A3 tubes, I'd be quite interested to heard your comparison to the others mentioned above. One of the things I've noticed with many of the new manufactured tubes is that they have nothing in common with the original except the type and printed specs. Case in point... the EML 45 triode. It's internal construction has absolutely nothing in common with the original 45 beyond the spec sheet. Still, I've found they don't bias the same and they don't sound that great until you push them harder. On the flip side you can get more power from them with a bit extra voltage and bias current... and they still barely get warm.

Regards, KM

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