Mel,
Here is the switch I am using for my A/B speaker test. It also has source A/B. You need to be sure to turn OFF the prev. amp (or speaker) BEFORE turning on the new amp (or speaker). I don't know if issues would arise, but after Jay's story, I wanted to be careful. It does have a protection circuit, but decreased SPL on speakers about 1.5-2 dB. No idea what else the prot. circuit might influence, so I left it off.
I don't recall what I paid for this 10+ years ago, but it must have been inexpensive for ME to buy it.
