rvpiano
To your question to Wolf, no you can sub in 6sn7s for 12au7s or 12ax7s
Here's the link to Brent Jessee' website (sells mostly NOS tubes) if you scroll down a bit to the yellow section where you see different tube types listed click on 12ax7 and it will bring up not only his list of available tubes but impressions on various respective brands; you can do likewise for 12au7, etc. (Note: I am not Brent nor affiliated with his company other than as a customer) - Might be helpful. Also , if you call him , say Andy at Vintage Tube Services and tell them what type sound you are looking for they can steer you accordingly.
To your question to Wolf, no you can sub in 6sn7s for 12au7s or 12ax7s
Here's the link to Brent Jessee' website (sells mostly NOS tubes) if you scroll down a bit to the yellow section where you see different tube types listed click on 12ax7 and it will bring up not only his list of available tubes but impressions on various respective brands; you can do likewise for 12au7, etc. (Note: I am not Brent nor affiliated with his company other than as a customer) - Might be helpful. Also , if you call him , say Andy at Vintage Tube Services and tell them what type sound you are looking for they can steer you accordingly.