"Robert Morein" said:

I built a box using double-throw switches that I got from
Radio shack.

A really bad idea.
I actually made this mistake. I was interested in exploring ABX, so I put
together remote controlled relay boxes using Radio Shack relays.
These cheap relays have iridium plated contacts, which have signficant (to
audio) contact resistance. While entirely adequate for switching power, I am
convinced they are not transparent for audio.
As I recall, Arny did a more thorough job. He used silver relays, which
probably means silver/silver oxide, which have a much better chance of audio
transparency.


For line level switching, use double contact relays with gold plated
contacts in parallel per channel.
For speaker level switching, use double contact relays with one gold
contact and one heavy duty silver contact in parallel per channel.

--

"Audio as a serious hobby is going down the tubes."
- Howard Ferstler, 25/4/2005