Balanced switch for preamp output

Why do you need a switch? Your preamp has two pairs of balanced outputs. You can connect both amps to the preamp, and simply power off whatever amp you're not using.

I'd bet Ayre could make a switch for you. There is a new guy, Jake Forsyth, who is answering tech calls. 

Ayre is pretty good at adding mods to their equipment. I know they can add a high pass to their amps in order to use Vandersteen subs. You just have to ask. ( And, usually, the price to convert is very reasonable).

Bob

@dbphd 

If you're still looking, here's a few:

Kramer VS-4X 4x1 Balanced Stereo Audio Switcher (XLR)

Nobsound 3-IN-1-OUT XLR Audio Switch

Coleman Audio MS6 6-channel Auxiliary Switcher

Thanks, dpop, the Nobsound seems to exactly what I want at a reasonable price and the convenience of Amazon.  I've ordered one.