Russian Tube Preamp, No Return, Here I go again

lewm,

thanks for looking this up, very helpful.

I agree, thousands of hours, and, my office system gets less work than the main system. On the other hand, it could arrive smashed.

It was a 'what if?' and, my recent lousy sounding 6SL7's for my Cayin is a warning about spending money for the wrong substitute. I got lucky, my 2nd choice was a winner.

If it sounds great, a direct replacement may avoid a tube chase.

6N23 = 6922, etc. They are the same tube so far as I can tell.

lewm,

thanks as usual for your help.

any thoughts on using these adapters?

https://www.tubedepot.com/products/6sn7-to-6922-adapter

just curious, I am not sure 6sn7 would fit in/thru the case. 

In a word, don’t.

Elliott, even if the pin out is the same and the operating characteristics are very close it's always best to look at the filament current draw on the data sheets and compare. I would suspect being a larger octal tube that there is a good chance it will load the transformer more. Not worth risking it unless you know the exact specs on the transformer and there is plenty of reserve.
BillWojo