The On/Off times are kind of slow, probably ok as you will not be switching on & off with great frequency.The On-Resistances are kind of high, which may impact your frequency response.
I am working on something similar right now with my son.This post from a different forum should help http://www.diystompboxes.com/smfforum/index.php?topic=95572.msg840828#msg840828. I have tested the circuit shown on a breadboard, and it works well with no popping sounds. It is important to not just send power straight to the relay, or it will bounce back and forth when the power hits it, and you will get a nice popping sound.The relays I am using are 5V 1A (TQ2 Series). Futurlec has great prices on them, but they are SO SLOW.Here is a great link on the topic that got us thinking about this project. It is several years old, and is a manual system (no arduino), but his explanation how to eliminate noise while switching is helpful. http://www.geofex.com/article_folders/rmtswtch/rmtsw.htmGood luck,Rob