Four Hour Tube Amp Warm-Up

From the Pass XA25 owner manual...

Leave it on or turn it off: The product is designed to be left on all the time. The exception to this might be a case where the unit will not be used for an extended time - in that case it can be turn off. The main power switch is located next to the AC power cord. (THIS REFERS TO THE REAR MAIN POWER SWITCH)

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You are now ready to play music. Turn the level at the source or preamp to a low level. Press the power switch on the front panel of the XA25, the blue LED above the power switch will light. Turn the volume up to your preferred listening level. Sit back and enjoy! The XA25 takes approximately an hour to fully warm up and sounds better as it does. Pushing the power button on the front panel of the XA25 a second time turns it off and extinguishes the blue LED. (THIS REFERS TO THE FRONT PANEL POWER ON PUSH BUTTON)

@bigtwin Heed Audio, Simaudio, Pass Labs, SPL, AVA, just to name a few. 

bigtwin wrote: "I'm not aware any any manufacturer that suggests leaving equipment powered up 24/7?  I would think you are only shortening the eventual life span of things doing this?  Just asking."

@jerryg123 Thanks.  I stand corrected.  My manufacturers, Hegel, Esoteric, Triode Audio Japan, PrimaLuna, all recomend turning equipment off when not in use.  Oh well, whatever works for you is all that counts.  Merry Christmas.  

@bigtwin I cannot think of a single Tube Amplifier manufacturer that would say leave it powered on. Nor a Hybrid tube SS manufacturer.  

It’s difficult to really know for sure because I’ve not listened to the same music at 30 minutes, 1 hour, 2 hours etc. It’s also difficult to remember & accurately compare w/ that time lapse in between. I don’t think our sonic memory is that good over time, even relatively short amounts. 
 

“Warm up” time could also be be within in our brains & it takes me time to relax, unwind & really get into the music & really enjoy it.

That all said, I have noticed w my Rogers EFH 200 Mark II ( 2- KT 150’s per side & a seriously large power transformer) that the sound definitely sounds more full body & fleshed out after about 1 hour. Beyond that , I can’t say much.