It can also be done with my sequenced turn on/off schematic. You can use that to mute/unmute and switch a speaker relay in a sequence that makes the speakers only connect AFTER the unmuting and disconnect first BEFORE unmuting...
You can use it on any supply voltage as long as you choose capacitors with the right voltage rating, and off course you need to choose the correct relay coil voltage... A 24Vdc relay can work well when there is a resistor in series with the coil.
This circuit can also add more safety for the speakers when you connect the Hmute function to the transistor that earths the speaker relay.
Last edited by V-bro; 19-Nov-11 at 13:19.
Pics can help a lot to diagnose something from any place on the globe...