You could use a switch that uses a 12V trigger to switch between the two.
bi-amping with Tube and SS amp
Bi-amping question:
Is it possible to use a tube amplifier to run my HT speakers without disconnecting HT SS amp?
In other words, can I connect a tube amp to my L R channel using top binding posts and use the tube amp for music. The HT amp will be off but remain connected via bottom posts.