So, I understand the basic differences between 12ax7, 12au7, 12at7, and 12ay7 when placed in V1. I just purchased an reissue Ampeg Jet J-12T and it has 12ax7s in both V1 and V2. I think V1 powers the tremolo, as well, in this amp. I love the way the trem sounds, but would like to warm up the pre-amp with a 12ay7. Where do I put it? V1, V2, or both (or neither)?
Here's a schematic...http://www.ampeg.com/pdf/j12t.pdf
It's on page 12 and kind of oversimplified, but it does the job.