If you don't mind using the Cary for music and HT you could pass your front L+R outputs through it for HT. You will need to use your pre-outs from the Sony to the Cary. If you do this, you may want to use the Cary at 80 watts for HT. It's easy to do but will require tubes to be on for both.
The only other thing I can think of is for you to run two sets of speaker cables and swap them at the speaker for each use.
Dave
The only other thing I can think of is for you to run two sets of speaker cables and swap them at the speaker for each use.
Dave