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?

It appears your A21+ amp is consuming 1-watt on StandBy mode, and its very possible you’ll hear a difference after 2+hrs of warmup-play, sure. I tested a smaller A23+ a few months back and it sounded better after 1-2hrs.

Most good ClassA solid state amps I’ve owned sounded pretty bad at 15-30 minutes from cold startup, and once the large transformers became warm and fully saturated, I could always hear notable changes at 1hr and 4+hrs. Some other well known Class-A amps notably improve after 8-24hrs warmup once everything becomes nice and toasty. I’m not sure I’d leave an ultra high-end Class-A SS amp on other than for weekends or long listening days.

With my current tube mono amps, 1hr of warmup is all that’s needed and the sound really does not change after 1hr. Varies some by amp type and design of course, type of transformers used, YMMV.

So if I’m using little fans to manage the temperature of my SS amp, does that mean it’s not warming up sufficiently to play at its fullest potential?
I am totally off grid(closest power pole is 2miles away) ,I have solar ,generator backup and lithium4 batteries . I do power my hybrid down and it takes a solid hour min, to get my system to open up. I run class D in my video room that is always in standby mode .

Temperature changes will change the biases in transistors and hence make differences.

It is almost like an ICE engine.  It runs better when it is warm.

Unless your amps are choked for air in a cabinet I've never been a fan lol .class A gets so hot its hard to even touch and I would leave on 24/7 . My hybrid tubes get hot!