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. 😉