I do not leave my four Pass Labs amps on all the time due to the high bias they are always in class A. Although I expect the input stage is still idling and the heat sinks are cold.
When turned on the heat sinks start "tinking" and when they are done with that I'm good to go. But it does get better after that warmup and continues to get better. I believe its my ears/brain just settling in to the groove.
As an aside, although subjectively they sound better I have put sensitive thermometers on the heat sinks and after no more tinking the temperature remains stable at ~109 degrees.
Regards,
barts

