03-05-11: Tmsorosk
Paper ... You may claim thermal switching is B.S. but several manufacturers of equipment I own as well as my long time dealer tell me that leaving things on reduces brake down rate , Iv'e followed there advice for many years and have found this to be true. What do they no eh . Do you no a manufacturer of S.S. equipment that states otherwise . Class A amps that run very hot may be the exception.
if you just took the word of the manufacturer yet don't know what failure is that is being prevented by 24/7 operation, then you don't know whether you are just accepting a bill of goods. if you uniformly believe what you read, then you sound like a prime candidate for $15,000 interconnect cable.
the reality is that product failures are often characterized by a "bathtub" curve where there is a period in which you have a higher failure rate early (this is referred to as "infant mortality"), a period where the predominant failures are random failures, and a period where failures result from the product just wearing out. a company that has reasonable quality control processes should screen for infant mortality. this screening is typically referred to as product burn in. this kind of burn in is different from the meaning of "burn in" as used by audiophiles. burn-in testing often tends to weed out infant mortality by testing at elevated temperatures and/or voltages. i can believe that there are manufacturers who don't have such good quality control processes and they ship products out without burn in testing. my amplifier and pre-amplifier are by bryston. one good thing about bryston is that they openly disclose their processes and they describe the burn in process that they follow before shipping products. the company that supplies your products may not do any such burn in.
proper burn in testing will have a lot more to do with the likelihood of reducing product failure than this 24/7 stuff that you are repeating.
here are the comments from pass labs on product life from one of their power amplifier owners manuals:
So how long will this hardware last? It is our experience that, barring abuse or the odd failure of a component, the first things to go will be the power supply capacitors, and from experience, they will last 15 to 30 years. Fortunately they die gracefully and are easily replaced by a good technician.
After that, the longevity will depend upon the number of operating thermal cycles, but we can say that we have had amplifiers operating in the field in excess of 20 years with no particular mortality, and we dont have good information beyond that.
More to the point, you should not worry about it. This is a conservatively built industrial design, not a frail tube circuit run on the brink of catastrophic failure. If it breaks, we will simply get it fixed, so sleep well.
what pass describes is a wear out failure mode (capacitors) and the possibilty of random failure (which they say they will fix).
03-05-11: Tmsorosk
And as far as a sonic difference goes , my own ears as well as other well respected audiophile friends have tested the affects of turning off large power amps and the results are consistent , etched sound for hours to days , one of the few things we agree on . Have you done such tests for your self , Or are you a theoretician.
the reason why i mentioned theory was to suggest that the stuff about how equipment sounds better after warm up may not be complete bs - that there is some theoretical basis for the claims. for my own part, my view is more like that of cmjones: after 15 minutes i'm not going to remember how the system sounded then with enough detail to make a meaningful comparison with how the system sounds later.
