solid state gear- leave on?

Well designed electronics are not "stressed" by turnon and turnoff. Fifty years ago my tube power amp had a "soft start" circuit. Actually it was just a wirewound resistor with a bimetalic strip with switch contacts on it. The resistor was in the AC power line, so that initial turnon was at reduced voltages, but when the resistor got hot the contacts on the bimetalic strip closed and shorted out the resistor so that full voltage was applied. Must have cost about 25 cents. Nowadays a "soft start" circuit is probably more sophisticated, but there is no excuse for the designer to completely ignore the turnon requirement.

My digital power amps have a turnon sequence which they execute, and it even includes diagnostic checks in the process.

As a member of the baby boom generation, having been brought up by parents who went through the Great Depression, I guess I have this knee-jerk reaction - I can't leave a room without turning off the lights, unless I'm going to be right back, I close the refrigerator door ASAP, and I can't leave my audio equipment on when it's not in use. I turn off my computer when I'm not using it, too. I'm also very concerned about our natural resources and the environment. I guess I pretend this is saving Mama Earth in some very small way. As I said, it's second nature for me, and I can't escape years of behavior modification; audio nirvana is forced to take a back seat. :-D

El: Obviously, "well designed" has different meanings to different designers / engineers / end users. There are those that feel that the addition of ANY unnecessary parts / circuitry is a poor design. Then again, there are those that think that a unit without every form of circuit protection known to mankind is a poor design. Personally, i prefer that the units be built like tanks with only the bare essentials in terms of circuit protection. To each their own... Sean
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I personally spoke to Pass Labs about this issue. If anyone should know, they should, especially being under the tutelage of Nelson Pass. The answer? Basically a toss-up, as heat ages things, especially capacitors. I think those who believe 24/7 is not stressful are remiss here Capacitors that are kept in a fully charged state most of the time (listening sessions being far shorter than 24/7) only shortens their life span and 'dries' them out sooner.

As others have stated here, well-designed gear has circuitry that prevents an initial unrush of current upon turnon. Such as my Halo amps.

Sean...Of course "Well designed" applies to the protective circuitry also. Protective circuitry should be designed so that it does not affect performance. If this is a stated requirement it can be done. This rule applies not only to performance, but also reliability. Any protective circuit, if it fails, should not affect operation, thereby degrading reliability...false alarms should be recognized as such and disregarded. (Come back and fix them later).

There are two schools of thought regarding the merits of "Continuous Operation" of missile guidance systems. Some are kept "spun up" and ready to go all the time. Some are kept in a temperature-controlled "dormant" condition, and only spun up within minutes of launch (if I said how many I would have to kill you). Of course there have been intensive studies regarding the effect on accuracy and reliability of the frequent spinups and shutdowns of the dormant systems, and the bottom line is that, if the system is designed to be operated this way it is more reliable than continuous opearation. This is contrary to what people tend to believe from their everyday experience with light bulbs, which always die with a flash on turnon.

You are right that additional circuitry will TEND to degrade reliability, and can affect performance UNLESS the designer addresses these issues.