does your system "warm up" and then sound better?

Most of the solid state amps I've had or heard in my system took MUCH longer to sound their best. The latest that I heard in my system was a friend's First Watt J2. It sounded very good from turn on, but delivered better dynamic shading and a large soundstage after it had been on for about 45 minutes. While that amp runs a little hot, I think it is one that I would turn on at the beginning of the day and leave it on for most of the day.

A friend's Krell, which operates in class A (so it naturally runs very hot) took much longer than that to sound its best, which would be a problem because that amp is one that should not be on all of the time.

The various solid state linestages I have owned, such as the Placette Active and a Levinson No. 32 stayed on all of the time. Both would sound lifeless if not fully warmed up. The Naim folks said that their CD players should be left on all of the time and take a minimum of a whole day to sound decent if shut off for a long period. They claim that optimal performance is reached after one week of full time operation. I think that is really overdoing the warmup bit, but, I don't turn it off because it is intended to be left on all of the time. My solid state FM tuner is never turned off even when the switch is in the off position (off turns off the display only) because the manufacturer thinks that it takes a long time for the tuner to become stable after it is turned off.

I know there are tube gear people who also don't turn off their equipment because they think it sounds better that way. But, for me, that would be WAY crazy, particularly since my amplifier runs four tubes that now cost $1,000 each and the linestage runs 4 tubes that are closing in on that kind of money too, and the phono stage. . . you get the picture.

Larryi, cool, thanks! It's sounding like I should just leave all my gear on 24/7.

Anyone who said warm tubes would sound better is correct. They sound much better than cold tubes. I was thinking of the leaving them on all the time part of the question,

Even with solid state gear, there is some debate about the disadvantages, in terms of equipment longevity/reliability about leaving gear on 24/7. First, there is a possibility, however remote, of failure that could cause a fire. Second, there is the issue of lightning strike or other powerline calamity (some people unplug gear completely when not in use to prevent that kind of damage). The third concern has to do with heat--high heat will shorten the life of any component. If you look at specifications for parts, such as resistors, transistors and capacitors, the lifetime projections show shortened life expectancy for higher heat conditions. Some people will say that certain parts, such as electrolytic capacitors are actually better off being charged all the time, but, the flip side of that is the heat issue. One should check with the manufacturer about this sort of thing if ultimate longevity is a big concern; in terms of sound, fully warmed up gear, whether tube or solid state, sounds better.

I very carefully experimented with a Unico hybrid. It would take two days to sound its best, with significant changes at 2/4/6/8 hour marks. Even swapping hot tubes with cold, the amp otherwise fully warmed up (i.e. on for at least two days), took four hours for the sound to stabilize (and improve). I tested over several weeks, rolling my fair collection of 12AU7's. Speakers were Fostex F120A single driver augmented with electrostatic super-tweeter.
-- William