Optical to Coax converter

Does anyone know of a good optical to coax converter? I have two machines with optical out, but my d/a only has one optical in...

I think Parts Express sells one.
Anyway, I am using it on my Panasonic DVD Recorder and it seems to work fine. Cost about $25 bucks!
The monarchy looks good - I also found one from Audio Authority that automatically switches - will this affect anything, soundwise?