Speaker quick disconnect on poweroff

[bobbyprajan]

I am looking for a simple circuit to disconnect the speaker from the amplifier outputs when the mains power switches off. There is a pronounced thump from the speakers when I switch off the amp now. I dont have much space in the cabinet that houses the amplifier board. The amplifier is a TPA3255 evaluation board

 

[mbhangui]

Make a small cabinet with two relays, one power supply to power the two relays.
Two binding posts for input from AMP for left channel
Two binding posts for input from AMP for right channel
Two binding posts for output to left speaker
Two binding posts for output to right speaker

When the power goes off the relay will disengage cutting off the speakers.

You can also incorporate a speaker protection circuit in this small cabinet. There are plenty of speaker protection circuit available online