Thank you both Jim and Owl's_Warder for your responses. I don't think I made myself clear as I don't need a sensing device at all because I use these two (2) other amps for Zone 2 only. I'm looking for something hopefully much, much less than $150 that would be a basic button I push that would send the 12vdc trigger to these amps to power up only when needed. I'm NOT electronic savvy at ALL. Most likely something I could build myself...if I knew how.