6SN7 equivalents in B9A

[richwalters]

The ECC82 has figures which are sim but audio performance is horrible.
Anyone come up with other B9A's with comparable 6SN7 performance ?

richy

[DigitalJunkie]

6CG7?

[Colt45]

cg7, fq7.

[dsavitsk]

Originally posted by richwalters
but audio performance is horrible.

Oh, please -- maybe it isn't as good as some other tubes, but horrible? I bet in a blind test 12au7's and 6sn7's are indistinguishable to 99% of us.

[Lingwendil]

Originally posted by Colt45
cg7, fq7.

Ditto, they both are excellent tubes, the only complaint I have with them is the low gain, which isn't a deal breaker


If you can find them in 8 volt heater version they are often cheaper too!

[richwalters]

dsavitsk;
Sorry for that one... (I have to expect some backlash from avid users)...I simply just don't get on with the ECC82... perhaps historical or have grotty samples.....It does have a poor FFT spectrum.

DigitJ- Thanks for 6CG7....Ah!. I really should have realised this one.

richy

[dsavitsk]

If you haven't seen it, John Atwood has a nice writeup of history and types at http://www.6sn7.com/

[m6tt]

As many of us have discovered, most of the old tube manufacturers liked to reuse parts. If for instance your circuit required a high mu dual triode, and a low mu, 6sn7-like dual triode, you should consider using two dissimilar triodes. Some of them are remarkably similar to 6cg7 and 12at7 specifically. They seem to have been common plate & cathode structures to use for medium and higher mu purposes in lotsa TV tubes etc.

[wa2ise]

If you can find them in 8 volt heater version they are often cheaper too!

And if you have 12.6VAC available you can just use a rectifier diode in series with the heater (without any filter cap) and it will operate normally. Power is V^2/R, and the R is not the same, and with the unfiltered diode 1/2 (V^2/R)

(12^2)/2 = 72, and 8.4^2 = 71 which is close enough. I took out 0.6V from the 12.6V for the diode drop (which is not exactly the same as 12VAC, but for this purpose that can be ignored)

[Wavebourn]

6N1P was offered to designers as a replacement for obsolete 6N8S (6SN7 analog)