Solid state power amps.; on or off?

I never tried leaving an amp on all of the time until I read this thread and have started to leave it on now, I am a believer! After just a few days I have noticed a HUGE diference in sound in the most crutial moments, the first few minutes of listening actually sound good, go figure!

....any component that lasts 13 years with either no servicing or just one servicing is a gem. Craig.

Yea Craig, if you ever have a chance to pick up a Proton, they are ausume. Best piture tube made (Hattachi). I got mine at a close out dealer for 70% off and it was still over $1000, but that was the first and only issue I've had. Now it just needs to last another 13 so that HDTV finds it's place. J.D.

I have started turning off the Musical Fidelity SS amp attached to our mini system due to the power problems in California and it does not sound as good at it did before (when left on 7/24), not nearly as much detail at low listening levels which is how I use it in a near field setup. I still leave the CD player on as it does not draw much current.

I left a Cello Duet 350 powered on for most of eight years -- only took it down for vacations, renovations, cable changes, etc. Bought it in 1992. Now it runs in my home theater and is powered up only when the system is active (maybe 4 hours a week) -- but it certainly suffered no ill effects. One caveat is that electrolytics have a rated life -- so they will age more quickly if the amp is left on; the semiconductors, it seems to me, benefit from being left on (fewer transients and fewer temp changes). Since the amp is now nine years old, its capacitors should be replaced. I used to manage service for $5-15 million (per copy) mainframe computers -- and the absolute worst thing that customers could do was to power them up and down -- the process inevitably shook out the weak components. A machine that had been powered up for months, once powered down, was a good bet NOT to come back up without some expensive repairs. Those experiences have always left me convinced that electronics (w/o moving parts) are probably more reliable if left on.