Are Their any Tube Preamp with Home Theater Bypass?

IF you are using the system as your main 2 channel music and alternately as the front for a Home Theater via AVR:

then tube preamp is more desirable, thus tube life will be increased, but I would not avoid tubes IF tube sound is desired for the 2 channel use.

as noted, small tubes last 10,000 hours, and they do not cost too much. Always have a spare set ready.

the model that allows HT Bypass input to be used while the tube preamp is OFF sounds ideal.

new with proper features is wisest of course.

you need the AVR to control the volume of all speakers.

HT Bypass is an INPUT, the AVR controls volume of all channels together, sending front l and r into the HT Bypass INPUT., using your stereo amp for those, and using it's own amps for center, surrounds, and sub out.

Older tube preamps: tape loops or processor loops would allow the AVR to control the volume, and you select 'tape monitor' or 'processor' for that input.

processor out to avr, avr back to processor in.

tape out to avr, avr to tape in/monitor.

then you do the channel adjustments in the AVR menu.