Originally Posted by fatbottom
The only power amp I am aware of which can switch off unused channels is one of the Tag Mclaren amplifiers.
For typical av pre switching on your poweramp (from standby) you need a 3.5mm mono to 3.5mm mono cable, if both have the 3.5mm jacks. For my MC-8 the trigger outputs are on a screw down trigger block, so you just snip one 3.5mm end off. The ATI amp has 3.5mm connector.
Funny, my old amp is the Tag McLaren 5x100R and it's got individual triggering of unused channels. But it only works since Tag McLaren used a custom data channel between all units to allow special functionally and syncing between units. Instead of a simple "one bit" (on/off) triggering cable they had a data bus with Ethernet type cables—one Ethernet cable for data in and one cable for data out on each unit. They probably had their own protocol and signal interface, but 8 wires in each cable and separate cables for in and out makes it easy to communicate complex information. Like which channels are used to allow the amp to switch them off at the power stage to lower interference between the amp channels and to lower the temperature and electricity used.
The downside is of course, when you mix with units from other manufacturers. Like now when I need to temporarily replace my P5 amp with Tag McLaren, I have no way to trigger the Tag on/off and it doesn't have any automatic mode. Need to manually press the power button. Like in the old days! :-)
Thanks for the info on trigger cabling! I will get a cable and try tonight. Just for completeness. I still want my P5 to work without faults even if I may find a work around. It just doesn't feel right to have a half-broken amp, especially consider the amount I paid for it.
But still, I've had the Anthem P5 for about five years now and during that time it has worked flawlessly and it's a superb sounding amplifier!
I do like your idea, to have multiple trigger ports on the amp and AV processor to allow separate triggering of stereo and multichannel sound. Similar functionality of the Tag McLaren system but with simple conventional technology instead of a proprietary data bus.