The Pass XA25 uses 240 watts at on/standby. I can't see $20-35 a month in extra power usage. I usually turn it on ahead of time and it does sound better after warm up. Some components need to get to 50C to sound right.
Amplifier warm up
I was plalying Boz Scaggs, "Silk Degrees" LP. After side one, I ate dinner. One hour later I played side 2. The second side sounded clearer, more vibrant with better sound stage. I have a Parasound P6 preamp and Parasound Halo A21+ amp. Is it possible that an hour of warm up improved performance?