Warm up time


The mfr of my preamp (Pass) states in the manual that it takes at least 24 hours warm-up time before critical listening and I’ve found that to be absolutely the case. Recently unplugged it for a brief time and I had to start all over again. It’s not a difference that’s hard to hear.
Anyone out there know why this would be?


Some (including you): It’s true!
Others: It’s BS
Some: It takes time for the components to stabilize and warm to optimum operating temperature.
Others: That only takes a few minutes.

That pretty much covers it. :neutral_face:


My own experience is that digital equipment unplugged and left to cool can take 24 to 48 hours to sound its very best. Don’t ask me why, I don’t have any convincing arguments that would satisfy skeptics. It just is what it is in my estimation.

My tube amps take about 90 minutes to sound very very good, but I swear that if left on for a few days they enter a new plateau of juicy lush goodness…


I’ll ask Pass Labs and post the answer here.


From the nice folks at Pass Labs: (the dumbed-down version; me doing the dumbing down)—
My SS XP-20 preamp operates biased to class A. Since this is a very low wattage device, it takes a long time to heat the mosfets to the point where they need to be for their maximum performance and since even small variations in temp will reduce the mosfets performance, a homeostatic state must be achieved and it takes that long to warm not only the mosfets but the environment around them.
The difference between just powered up and 24, or even 36 hours is from unlistenable to sublime.