Hi,

I'm looking for a circuit that would automatically turn on my amplifier when it detects input from a line level. I would be happy to have it pass the signal through, and use a relay in series with the power supply (120VAC).

Has anyone seen a circuit like this? I haven't found any, either in books or on the web.

Thanks,
jptrsn.

 

Here's a squelch circuit - http://electroschematics.com/wp-content/uploads/2008/05/squelch-schematic.gif