Concerning whether class D amp performance improves by leaving them constantly on 24/7, I tend to agree with erik_squires that there are sonic benefits.
I initially turned all of my class D amps(2 stereo and a pair of monos all with linear toroidal power supplies) off each night, with amp off/down times varying between about 6 to 20 hrs/each. It was fairly obvious to me that my class D amps required some warm-up span of time to reach their optimum performance levels once they had been turned off for 6-20 hrs.
How long did they take to warm-up?
I didn't record time trials but I subjectively recall a time range between about 15 minutes and an hour.
After a few weeks, I then began just leaving them on 24/7 and I could clearly hear my amps remained at a optimally warmed-up performance level.right from the get-go.
For accuracy sake, it should be noted that my perceptions of when my class D amps are optimally warmed-up is a subjective measurement based on my ears and amps so YMMV.
I should also state that, even if this warm-up period of my amps was proven to me to be a 'placebo affect', I would continue to leave them on 24/7 simply due to the impressive simplicity and convenience factors.
The main point I want to make, however, is concerning the statements from slimpikins and georgehifi of " As far as warm up is concerned, I cannot hear any differences in a cold start up vs. the amp having been on for 4 hours... other than Bourbon has taken over and everything in the room is just better."
Besides this statement being mildly humorous, I'm not sure these gentlemen understand that their agreed upon confession logically leads to only one conclusion of leaving class D amps on 24/7.
Since turning class D amps off would result in insignificant electricity and monetary savings, and since both of these individuals are admittedly unable to discern the sonic differences between cold and optimally warmed-up class D amps, why would they not just leave these amps on 24/7 and gain/enjoy the dual benefits of simplicity and convenience?
Do they have a phobia of a highly unlikely fire?
Are they overly sensitive to the minute levels of heat produced by idling class D amps?
Are they adverse to the simplicity and convenience of having their amps perpetually and immediately operating at the first inputted source signals?
Are they being overly argumentative due to personal biases against the current large crop of good class D amps because they're not yet perfected?
I really don't understand.
Tim