Hi Ed,
- Is a "bypass" mode available on the Signature 30.2 Integrated Amp or upcoming Isabella Pre-amp?
There is no home-theater bypass mode available. The Isabella is designed for dedicated 2-channel listening pleasure. If you are looking to mix in HT, this is probably not the best choice for your needs. There are other preamplifiers on the market that have the HT bypass feature.
The only other option that I can think of (if you want to use an Isabella and RWA amp for 2 channel listening with the same main L and R speakers that you use for a HT setup) is getting a high-quality amp selector switch. The switch as L and R inputs for two amplifiers, and the output of the switch is the L and R speakers. When you want to connect your 2-channel source/preamp/amp to those speakers, you select one input of the switch. When you want to connect your HT receiver to the same speakers when watching movies, you select the other input of the switch.
I have actually made such a high-end switch for a customer for this very same application. I used high quality speaker binding posts and a very high quality switch (very low contact resistance, silver plated contacts, high current rated, etc.) all in a fairly small enclosure.
IMHO, using such a switch will sound much better (or should I say "hurt the sound the least") than using your HT preamp in the signal path to feed your high-end 2-channel amp when listening in 2-channel mode.
Best regards,
Vinnie