....but unless I'm missing something, neither of the suggestions are quite what I was hoping for.
I want the volume control to be on the front of the SS amp -- the input sensitivity should be 250 mv or better. Currently I'm using the volume control on the tube amp as a primitive tone control, and it works quite well in that I listen to a wide range of material with some being a bit too bright (the most common problem), and some not bright enough. So "treble adjustment' is very important to me (and my pre-amp, an AR SP-16 does not have tone controls).
Now that I have a bypass switch on my tube amp, and can skip the tube amp's volume control entirely, I am getting a sense of the sleight veiling the volume control has been adding all these years. But I don't want to lose the capability of making fine adjustments to the bass vs. MT balance, so rather than attenuating MT via the tube amp, I want to be able to achieve the same result by boosting bass on the SS amp.
So why not just use a better attenuator on the tube amp? That may end up being my last resort, but another issue is that I often listen to (old-school, not modern brickwalled) CDs and 24/96 or 24/192 FLACs at about 75%-80% max volume on my pre-amp. If I can run my tube amp with the bypass switch engaged it, and have the SS amp "make up the difference", the overall effect will be to move that average volume level down to 65%-70% on my pre-amp.
So, an SS power amp (not integrated) with volume controls on front, plenty of watts per channel, and, say 200 mv input sensitivity. Suggestions/recommendations anyone?