Soviet NOS Substitute for 6SN7GT
 

The 6SN7 tubes are skyrocketing in price and being sold on eBay in groups of "matched pairs or quads" for the exploding vintage audio craze. I've been getting some tubes from vivatubes.com and bought 4 Soviet era NOS 6N8S substitutes for the 6SN7GT for $40...$10 each. So far, they seem to work well. I don't know if they are built to the standards of other Soviet era vacuum tubes, but these have a reputation for being overbuilt. We'll see. Anyone tried these tubes or other substitute swaps using tubes from the nation formally known as "The Evil Empire"?

No Soviet tubes here but I have used the 6FQ7/6CG7 in place of the 6SN7.
A few years ago I came upon a Baldwin organ that had dozens of 6SN7s (and tons of minty cloth wire) so I'm set for a long time (might be worth selling some).

The 6SN7 is just 2 6J5s sharing an apartment...

Funny, that's exactly where I got my stash of 6SN7s from. Crazy how many they used.

Just got a bunch of 6CG7 tubes. Good info.

“No Soviet tubes here but I have used the 6FQ7/6CG7 in place of the 6SN7.”

Did you change the socket on the chassis or build/buy an adapter? :scratch2:

jr

Adapters are easy enough to build. You can find sockets at swapmeets (or steal from parts sets) and steal bases off dead tubes (which is why I keep a shopping bag of duds), and pin outs and data sheets are a Google search away.

My '51 Zenith was very specific on using a 6sn7gta, 500v, where the 6sn7 was only 450v max. Wrong tube may cause deflection & linearity issues. I think the gtb version had a faster warm-up, and was better suited for series-strung sets.

Be nice to know how the characteristics compare.

It appears that max plate voltage specification of the 6FQ7/6CG7 is 350 volts or less...not a good substitute match for your Zenith. :scratch2:

jr