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?
aeschwartz
I have a new warm-up ritual now thanks to this thread. Before this I would turn on the amp, motor controller, and phono stage, all at least a half an hour before listening. Now I also let the motor/platter run almost as long. 

This has really made a difference in the quality of those first few minutes. There's still improvement across the first side, but its starting from a much higher level. 

Okay, don't want to exaggerate this too much. Its not like this is something everyone will even be able to notice. Obviously if we learn anything from threads like this its that there's all different levels of listeners. Some never will hear any difference. But for those who do, this is definitely worth doing.
I use tubes amps.  I warm them up no less than 15 minutes before use.  I also let the amps cool down for the same amount of time before powering down.  I started doing the warm up cool down many years ago and it increased my tube life nicely.
@vegasears 

have not heard of cool down concept for amps

not sure it matters, but pretty sure it doesn't hurt
I've definitely noticed that SS sounds better when left on all the time.  I only have a class a/b integrated and phono stage that I leave on, so it's not using much power when not in use.  Recently, I went out of town for a few days, so I powered everything down.  When I returned, I was looking forward to hearing my rig.  Those first few albums were pretty painful - everything sounded thin and glassy.  The next night, things were sounding great again.  I really wasn't expecting such a difference, but it wasn't subtle.  That being said, if I had a class A amp, I wouldn't leave it due to environmental concerns.  
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.