This how the amp would ideally work:
The amp would be a 1x12 Combo angled up towards the players head, where the ears are located. The front panel would have a 1/4" instrument input, Master Volume, and an "On" light. The amp would only have 1 Channel which would cover the entire volume/gain/tonal spectrum. Where the guitar sits in this spectrum would be controlled by one heck of an expression pedal connected to the back of the amp by one heck of a cable. At the "Heel Down" position, you would have the cleanest of clean tones. At the "Toe Down" position you would have more distortion than you would want. There would be a power switch, and standby switch if needed.
As the guitarist moves the expression pedal, the tone morphs along the volume/gain/tonal spectrum as seamlessly as possible. The amp would be a tube amp but in order to seamlessly morph the tone, the amp would probably need to be digitally controlled, similar to the Triaxis. Internally, everything would need to be "continuously variable" in order to maintain the correct proportions between the predetermined parameters that define the volume/gain/tonal spectrum.
The purpose of this amp would be to replace all "guitar tone controls" with the player's ear(s) and foot.
I have seen enough of these features in some shape or form in various current products that lead me to believe this amp could be built by engineers who know how to build amplifiers.
This idea is simply that: an idea. I am not asking for it to be built, but if it were built, that would be great. If any of you have an amp like this at home, that would be useful information.