I'm using a VTA ST70 amp that uses the 12AU7, but I'm actually using the 12BH7's in it's place. I have to say it is a stellar performing amp. It's crisp, articulate and bass can hold its own against any SS amp.
I just want to make this perfectly clear. This amp is an amazing performer. This all has to do with MY taste and nothing to do with the amp.
However ---- my taste leans more towards a romantic fuller midrange sound signature. I've tube rolled to the point were I know it's never going to be what I want.
I'm asking this as a last ditch attempt to warm up the midrange ONLY option. Knowing that the 6SN7 is basically an earlier version of the 12AU7, is there any chance this tube would present a more "romantic fuller midrange" sound in this amp????
I'm gonna be honest. I can get the same sound, and in many cases more pleasant sound. from my SS amps.
I've also considered reverting the driver board back to original and use my 7643 driver tubes.
You've tried all the 12AU7 iterations? If you have time to search and a bit of extra cash in the pocket... a couple of tube suggestions. Black plate CBS-Hytron 5814A and 7318. Those will warm the mids and keep the bass and top end. Need strong testing, quiet ones.


