Not sure if you're still around this forum, but does swapping in the 12au7 in V3 simply involve swapping the tubes or is there additional wiring that needs to be done? I'd like to get a bit more clean headroom out of my 18w TMB/EF86.
I'd also like to reduce the bass... don't really want to spring for a new OT right now though.
Thx,
Kerry