Mute all except for line in?

[rogersmj]

Is there some app that will let me play my instrument through the line in on my Mac but mute all other application/system sounds? I'd like to play through my speakers hooked up to my Mac (and maybe eventually record), but I don't want an instant message or a calendar reminder or any other random sound to blast in the middle of my playing. I'd like a one-click solution to muting all system and app sounds.

[Killyp]

Your best bet is to get a small, cheapo mixing desk and connect the speakers to the output, and the iMac to one of the input channels so you can mute it all at once. There is no way of quickly muting all the outputs at once other than the Line In.

In the meantime though, you can play through Garage Band (even if it is a little laggy). Just choose an input and click the RECORD button on the far left hand side of the channel, and then set monitor as 'on' in the right-hand pane of the screen.

[rogersmj]

Your best bet is to get a small, cheapo mixing desk and connect the speakers to the output, and the iMac to one of the input channels so you can mute it all at once. There is no way of quickly muting all the outputs at once other than the Line In.

In the meantime though, you can play through Garage Band (even if it is a little laggy). Just choose an input and click the RECORD button on the far left hand side of the channel, and then set monitor as 'on' in the right-hand pane of the screen.

Yeah playing through Garageband is, I've discovered, annoying at best.

You have any recommendations for a basic (and I mean really basic) such mixer/switcher?

[rogersmj]

Never mind, I wound up having such a device recommended for a slightly different question I posted (http://forums.macrumors.com/showthread.php?t=324879).