Interesting...such varying responses. I would not leave my amps and DAC on 24/7 because it sucks up a lot of electricity and shorten tube life. But it's a shame I have to wait so long to have my system sound so effortless, open, and natural. I wouldn't have believed it if I hadn't heard it.
How long it take before your system/amps sound
...the best. My system sounds the best after 12 hours of playing. I didn't realize this until I inadvertently left my system on overnight. I was surprised how much better it sounded compared having the system on for an hour or two. I have tube DAC and amps, which probably are the reason for long warm up. His really surprised me.