kirk1701 said:
...I just find the amp a little chirpy in the midrange. I like how fat, round, and legato it is. I like the endless sustain. It's just a little too strident--in your face. I want it to purr more. Does this make any sense?
Actually, it makes plenty of sense. If I were you, I'd first go with a good 12AT7 in the PI ...given what you describe, I think you'll be very pleased. Next, identify your preamp tube slots, if you haven't done so already. Isolate the Clean channel and Lead channel positions and work on them independently. On the 50cal, I can't recall how discrete vs shared each gain stage is, so that will affect how you swap your tubes. And of course, V1 affects both channels significantly.
On that latter note, you may or may not want to gain down the V1, as it will affect your dynamics and tone of the OD that I "think" you're liking so much. Think of it this way: if gaining down the V1 helps one channel, but now you don't like how it changed the other channel, put the orig AX7 back in the V1 and now try to gain down the channel that you *did* like in the previous attempt. I hope that make sense? BTW, you can "tune out" (so to speak) some of that midrange you don't like with AT7s as these tend to have less "middy" quality about them compared to AX7s.
Keep in mind these are generalizations, and each amp and tube will vary (so start with a few good tubes!). Ultimately, let your ears and fingers be your guide as there really is no substitute for experimenting. FWIW, I achieved what you want in my DC5, the 50cal successor. It turned an amp that I really did like into a keeper that I will never get rid of!
Edward