Just buy a tube stereo Integrated amplifier (or amp/preamp set) with a Home Theater bypass input and a nice AV receiver with preamp outputs.
When you're listening to home theater, switch to the HT bypass input, and you're rocking...the signal passes through the tube integrated amp (or preamp/amp combo) then on to your main speakers- volume is controlled by the Home Theater product
When listening to stereo, turn off the HT bypass mode, and you've effectively disconnected the dHome Theater processing from the stereo rig...you'll only be able to listen to sources connected to the Stereo Integrated amplifier (or preamp/amp combo) but that's what you're looking for. Perfect compromise