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

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!

DAC:

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+.

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.