[mythtvnz] FrontEnds Controlling Audio Mains Power

[Tortise]

I've been thinking about automating this for some time.  I recently got a USB powered set of speakers, that refreshingly turn on and 
off (and suspend also) automagically along with the FE's status.  Works well.

How do people do this for Mains powered Audio amps?   If the Amp has IR then I suppose one might successfully configure an IR 
suspend command.  (Maybe Ethernet connected Amps do WOL, but I don't know!)

A few listers will recall the old AT power supplies that included a mains out socket for the monitor.  How to do it with more recent 
PS?

I've been thinking about taking a USB extension lead / plug, cutting off the socket (or similar source) and feeding a relay that 
will switch 240V / 10A.  This would be nice in terms of the ease of plugging into the USB of pretty much any FE.

The relay could go in some small box, also with a mains cord in and a Mains socket on the box for the Amp.  A diode would be needed 
across the coil to negate any reverse EMF.

An alternative would be to use 12V from the FE power supply 12V rail, however one would need to more on the FE to make this 
available externally.   12V relays are probably cheaper and more standard however low coil current 5V relays may not be much 
different.

Anyone considered anything like this?