Listening after your entire system was powered off cold for a week+

Have you ever had your entire system completely unplugged-powered off for a week+, turned it all on, sat down for a brief listen, and immediately became disappointed with the sound after a cold startup?


With temporary amnesia, rediscovered again today for the 100th time there were no problems with my dac or tubes or any component failures going on.

@4-5 hours warmup, a radical transformation with the sound. Transformers on the dac, preamp, amps, all warmed up - - woah, here comes the missing tone, texture, soundstage, opening up nicely, and musicality. "There it is!".   Email this link to self, revisit periodically as prescribed. Maybe an isolated case :)



Yes, after Superstorm Sandy in November 2012 in Connecticut. We had no electricity for seven days. Upon turn-on my system sounded the same as it always has - excellent! So nice to be able to listen to music again!

Depends.  With Class D I've had to wait 2-3 days for it to sound better.  My current A/B integrated not so much.

Yes, definitely. At first listen it sounds pretty good, but then it becomes clear that the sound is a bit 'hard' all around. Things seem to smooth out after a few hours as you have noted.


To clarify it more, last week with hot weather and unpredictable (brownout) power in our area, I intentionally unplugged my RG power conditioner and everything in the system fully unplugged. Not something I normally do, usually listening every 3 days or so.

Normally I can power up the system and in 60 minutes everything sounds fine. For whatever reason this week it took 4-5 hours (this time around) after being unplugged 7 days. Would plugged-in vs. not plugged and turned off matter.

Its an all-tube system, tube DAC, tube preamp, mono tube amps and not sure that matters. At 1hr vs. 4-5 hours this time around, sounded quite different.

My local (50+ year in vintage electronics tech) who does a lot of mod work once claimed it has more to do with my unit’s "transformation saturation - and once all transformers in each of these four units are nice and toasty is when the magic happens", according his school of thought. A capable person who builds some really nice sounding pieces, custom built and modified AudioNote amps for ref. Someone who is super particular about all of the transformers used in all his gear.

I had a particular dual mono solid state amp with dual Torroidal transformers like this, always took (at least) 4hrs of warm-up and play time for it to hit its optimum operating condition and THEN it would sound right. Sligther better with 24hr warmup. Similar to what some Pass Labs owners report, taking at least 24hrs of on-time for things to sound right. My current mono tube amps (huge transformers) takes 4-5hrs to achieve its final set point. Perhaps this is old regurgitated talk for daily listeners who leave gear on all of the time. Happy Listening in any case. 😉







I don't have to disconnect anything for any amount of time to notice a difference upon start up. Whether it's the analog end, CD player or streamer, they always sound better after a half hour to an hour warm up. And keep getting better after that. Unfortunately that's the reality in my system. And no, it's not my ears getting used to it. Such is life when your system gets to a certain level. On a radio shack system it would sound the same cold or hot. Or at least you would not notice the difference. 


I leave my solid-state preamp on all the time.  The solid-state AB-class amps need 15 min. to sound right, and perhaps improve with more time on.   I would expect the system would need some time to warm up if the preamp were turned off, even if just a day or two.

My system sounds good after 12 hours, better at 100. Pre-amp only goes cold for extreme weather.

The OP’s system needs more time to warm up after a complete shutdown. Perhaps some of his equipment has a ’stand-by’ function, which ’sort of’ keeps it warm.

Most class A or class A/B amps and preamps need time for their capacitors to charge up and stabilize. The same for most tube devices as well.


Yet one more report of 1/2 to hour for better sound on a class A tube integrated. (If house AC isn't on all the better too due to white noise.)@decooney A whole house surge protector is your audio, AC and a raft of other electrical things in your house's new best friend. I also yank plugs... why not be better safe than sorry. A brown out once fried all our ACs and a few other goodies. 

I was gone for a week and when I returned today my system sounded amazing immediately, likely (obviously) because I hadn't heard it for a week. My Pass XA-25 always take an hour or so to sound its best, and I had a new Julian Lage album to enjoy...highly recommended by the way...he has Bill Frisell along on this one.

The soundstage changes dramatically over time with the pass labs 250.8.  But I notice that no matter how long I warm up the system, the system sounds better after 30+ minutes of streaming music. 

We (the company 'us') have left home base behind for a few weeks to 3 months, with an occasional 'speed tour' back with no leisure to listen....

Absence can make one's ears 'shift', imh experience.  Having been stuck listening to everything from jobsite machinery to supermarket music, and the random 'basser' next to in traffic, having one's gear go chilly may not be the main issue in mind or at ear.

Although passages, rifts, and lyrics may be in mind, the experience involved with ones' choice of musical means may seem to have a 'shift' in the comprehension of your personal preferences of medium methods.

It sometimes requires a day or three to 'recall' what you liked (or didn't) about it all.  Bear in mind that I'm referring to longer periods of 'withdrawals' ', as opposed to 3 day weekend jaunts....but your experience likely varies, the way most details do..

Thanks for this last round of replies, you guys read my posts more closely. Thx.

@terry9 may be on to something. Narrowing it down, I now think its my DAC more than anything else in the system. Possibly amps too when dead cold.

  • Last three days in a row, system sounded just fine after 1hr warmup - all left plugged in.
  • At 3+ hours warmup I do notice a bit more 3-dimensional layering and sound coming from the sides and slightly behind me with this particular all-tube system. Big transformers in amps warm by then!


My DAC is a NOS R2R Ladder design with a chip (not resistor type) and a TUBE in the circuit. At first I thought I had a failing tube or something, changed it to my spares. Nope, the prior tube was fine. Not the tube in the dac.

  • For some reason if I completely unplug my whole system and everything sort of discharges for longer than a week, its clear I need more (2-4hr+) time for warmup the first re-engagement of the whole system from dead-cold.
  • I accept the situation closer to what @terry9 shared above. Now re-learning again my particular DAC may benefit by turning it on for a bit sooner before listening, particularly if the DAC has been unplugged and off for a week+. Seems to benefit with earlier power-on time.  

Back to playing the system daily now. No issues, 1hr warm up is just fine.

Thanks for some of the more helpful replies here. ✅👍

Hope that solves your problem !   My HT all has 'stand-by' operation, and so it sounds good almost immediately. My listening room, however, is all class A and takes time. For that matter, my cartridge (Koetsu) requires 45 minutes to sound its best.

Yep @terry9 I should know better to expect more from a dead cold system that’s been unplugged/off for a while. Had countless solid state and tube systems past 44 years for audio and do notice similar benefit on my HT as well.  Some of my former/better SS mosfet amps truly transformed after 4hrs power-on time, always.

I installed more elaborate caps in my DAC, preamp, and Amps. An audio tech buddy also thinks my particular ones may be a culprit when unpowered a week+.


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Definitely the DAC, mostly. If I fire up the DAC all day long (at least 4-5hrs) before powering on the tube preamp and tube amps, sure makes a difference.

Tube preamp and tube amps do just fine after 1-2hrs warmup, as normal.

Mr. R2R NOS chip ladder DAC likes to be toasty to sound its best.  

My system is discernibly better after a week fully powered, even though the off switch powers down the amp

@stringreen good to know. Perhaps I had developed a conservative pattern of not powering things up as soon as I use to with my all-tube system, including my tube DAC. Over time I guess I slowly fell away from the benefit and realization of what a nice and extra-warm and settled system can do. Duh, bang hand against forehead.

With outside temps cooling off I’ve started to let things run longer before listening. Listening now with 8hrs warmup of the entire system and its really nice. Loving the system all over again. Just kind of re-surprised my forgetful self, again :) 👍


I do notice better sound when system is on as well as when it’s ‘up to temperature’. Though it could also be I warm up into listening too!

My setup is rarely powered off for more than a few days. That is, the DAC/preamp and digital XO is running 24/7, and so normally the sound has that sense of presence and fullness immediately after powering up the amps (3 of them; one class A and two class D-based) and music server, but after an hour so playing music/movies everything coheres and falls into place a bit better.

8-12 hours after being all-powered up (only on certain weekends, and not with the kWh price of electricity these days) a more pronounced sense of liquidity enters the stage, which must due to the class A amp "settling" more effectively, or so I gather. While a lovely extra addition to the sound this a wee bit more free-flowing sensation is not a "must have" for me to truly enjoy the presentation.

Having had the amps and music server turned off for more than a few days - like a week or two - can lend a stiffness, grayness and slight distance to the sound right after power up, and so the warm up change appears more radical and also takes a little longer. A couple of hours usually suffice here.

Interestingly the most radical boon during warm-up comes from playing my setup relatively loud (i.e.: 85-90dB range, slightly more in peaks) for an hour or so. This is most likely to occur during a listening session with one of my fellow audio compadres or watching a movie at ref. volume, and the effect is quite noticeable. When on my own I sometimes leave the listening room for 15-30 minutes and the music playing in mentioned dB-range, and it has close to the same effect. The sound just "pops" more freely and fuller after such a workout (that is, to my speaker setup it's hardly a "workout," but more like a light evening stroll), and so this is something I desire when listening more attentively. I’m guessing the speakers are to "blame" for this positive effect.

@phusis "Having had the amps and music server turned off for more than a few days - like a week or two - can lend a stiffness, grayness and slight distance to the sound right after power up..." 


Thanks for sharing the background and the details below it about how it sounds when you’ve had it playing more aggressively. I’ve noticed something very similar over the years yet failed to mention this in the OP. Interesting in any case, 👍

Most of what I notice is slowness getting Ethernet connected again with the network sreamer and innuos needing an IP refresh.  As far as sound, once everything is updated sound has been the same for me. I'm on comast if that matters.

I leave my preamp and CDP on 24/7. Only the amp gets turned off after a listening session. The pre and CDP get turned off and unplugged for about a minute then re-plugged and turned back on once a month to reset the electronics. 

Takes about 20 minutes for the amp to warm up and sound its best.

With all the monsoon storms we've had here in AZ this year, several times I've had to power down and unplug for several days at a time. For casual listening or background music, an hour or so of warm up is OK, but for serious listening, the SS Amp, DAC and CDPs take several hours to start sounding good and about 12 Hrs.  to sound their best. My tubed Pre sounds great after about a half an hour......Jim