5.1 A/B switch - XLR - where?


Can anyone recommend a (sonically transparent) 5.1 A/B switch with XLR connects?

To elaborate, I wish an A/B switch with two sets of (5.1) inputs & one set of (5.1) outputs - utilizing XLR/balanced connects. I can't seem to find anything suitable via the obvious search methods.
TIA!
salmonsc
Wow, so much more complicated than I anticipated ...
Thanks for the suggestions folks!

More than you need and probably more than you want to pay, however this Model 7299 Eight-Channel XLR Audio A/B/C Switch looks like it will definitely do what you are asking for, and have capability for up to 7.1 A/B/C switching.
Thanks Tls49 - it's actually cheaper than the $5k I've seen quoted for the now defunct EMM Switchman's - but still more than I wanted to pay...
Yes. I prefer the Zektors but they, too, are only available used. There are others, though.