Re: Power tube tone vs. SS tone (not preamp)
Most of the difference will come at the end of the volume window. So when the tubes are working really hard, there will be a difference in the dynamics. You can't really make a judgement on "tone" if by that you're referring to "more bass" etc. Any amp can have a sonic character built into it-and EQ "footprint" so to speak. So when you're not pushing it hard, it's a lot more like a SS amp. It's kind of like clean sounds. Sure the Fender/Boogie tube clean is rich and full, but not that different from SS when run softer. But a loud clean tube amp really sings. It's all happening in the dynamics, and how they respond to the different frequency ranges. So while you might not hear more lows, they could "pump" more with a cranked tube power amp. You might not hear more highs, but there could be some "crackle" in the highs with a sharp pick attack, that gets softer and rounder when you aren't picking hard. The SS amp will be more linear.
So if you're already using a heavily distorted (therefore compressed) sound going in, even a cranked tube amp will have less of an effect, because you've squashed the dynamics at the preamp. You need a clean or half-drive sound with no compression to really be able to feel and hear the difference. I'd say for you (revsharp) you could go back to a SS amp and it'd be no big deal. You'll get a more consistent sound across the whole volume range, too. But if you're running an SRV style sound through a cranked 1x12, you'll get hooked on the tube power.
My rig is powered by an old Fender tube head to a 2x12, AND SS power to both a 1x15 and a 2x10. So you could say that my fat dynamic mids are all tube, while my highs and lows are a cleaner, more linear SS. Although it seems to be the best of both worlds, I still would prefer tube power to the 10's and 15. I mostly record at medium levels with various degrees of half-drive tones. For a totally saturated lead sound sometimes I'll even go direct. Dare I say for a total saturated mega distorto sound even preamp tubes are less necessary. I hear tracks all the time that I know were layed with a Dual Recto. And by the time they get to "tape" it could've been anything, even a multi-processor. BUT to actually play one loud is a great experience. I'd love to record with one because the feel would make me play differently, and respond to the amp.
To recap, tubes are less necessary when you're doing all the dynamic and tonal processing at the preamp level. Why couldn't I have just said that instead of this huge rant?.....