The 'rule-of-thumb' is if it's solid state, then keep it on. If it's a tube based system then turn it off. My personal take is that it really depends on how long the system will not be in use. Obviously if it's a two week vacation than turn the system off regardless. If it's just a day or two than I think the rule applys.
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System should warm-up in less than 1/2 hour. Keeping system on all the time will:
1. Shorten life of your amp since elctrolytic caps life drops by factor of 2 for every 10 deg. Celecius.
2. Create unnecessary risk during tunderstorm/voltage spike (you cannot unplug being not at home or sleeping)
3. Still won't make system sound right from the start since other components need warmup time - for instance tweeters/ferrofluid.
You state that it takes an average of 30 mins to warm up an amp or A-V receiver before it will play at its best sound. Does that apply to solid state as well as tube equiment? I've noticed the sound is comprimised when I first turn on my receiver and play a CD. After a while, it sounds much better. Is 30 mins the rule then?
Pdn: I was talking about SS. As for time - it might vary and I don't know of any rule. I'm pretty sure the same applies to tube gear but have no experience there.
Stanwal: It might be better to leave computers on all the time (because of hard disc) but computers are often replaced before they go bad. The only component that ages in SS amp is electrolytic cap. As far as I know its life is only temperature dependent (except when left unpowered for years).
If your amp is not hot or cold to touch (body temperature) its life is already reduced by half compare to room temperature (10 deg. Celsius difference) - important only if you plan to keep gear for more than 10-15 years.
My experience and reading make me believe that the powering up and down produce more wear. I have transistor amps 25 years old I leave on all the time. I have never heard of heat being a factor in amp deterioration . I have often heard of an amp going bad from not being used. I think this is another case where theory and the real world differ. The ONLY argument I have ever heard against leaving them on is the cost of the power. In every case where I have seen this discussed the author has stated that leaving them on prolongs their life.
Interesting. I listen to music pretty much every evening I am home. That would mean turning the system on and off everyday. I agree with other posts that it takes time for the wires to warm up (I have long runs of speaker cable), so what is the difference in waiting for the amp and other electronics to come to operating temperature too? I have been leaving my gear on thinking it was better for longevity. Maybe its time to rethink that.
Stanwal - I stated what capacitor companies claim. Going bad when not used, that you mentioned, has place when you not use amp for long time (years) and aluminum oxide layer (serving as isolator) depletes eventually lowering allowable voltage and causing short at operating voltage - often exploding from the heat build-up. Caps have fuse (rubber plug) to prevent explosion. It is recommended in such cases to start at lower voltage (Variable transformer) until aluminum oxide layer will build-up again. Unfortunately some power supplies like SMPS either start or not and varying line voltage might not help much.
It is very difficult to compare performance of 25 year old amp with exactly same new one. I replaced power supply cap in old SS amp and got bass control and dynamics I didn't know it had.
I think that capacitors are just drying up and the temperature accelerates it. It might not fail ever but performance will slowly deteriorate since caps ESR rises up (thats why people recap their amps).
Stanwall - Check this link: http://www.dfrsolutions.com/pdfs/Uprating_of_Electrolytic_Capacitors.pdf
They mention temperature as main factor (and 10 deg C rule). ESR while getting lower at high temperatures (might explain reason for warmup) eventually gets higher from electrolyte evaporation.
Good quality amp equipped with 105 deg C caps might last for very long time while luke warm. I would like to preserve my amp at current state as long as I can.
Maybe if it's solid state, I wouldn't if it is tubed equipment, why waste the life of the tubes? I never understood what the advantage was to leaving it on. I have tubed equipment that I turn on about an hour before I want to listen to music, that seems to be enough warm up time. Even it I wanted to keep it on, my wife would never feel comfortable leaving the house all day with equipment turned on, afraid of a fire or something to that effect.
Cyclonicman - I don't understand advantage of leaving equipment on all the time either. Other elements of the system - like speakers also need time to warm up (playing time).
Even if Stanwal is right about miniscule effect of time on capacitors (electrolyte evaporation) in low temperatures there is no reason to keep it on - rush current doesn't do anything to capacitors.
I turn my system (class D) on every evening ant turn it off at night. On days of bad weather forecast I unplug it from the wall.
The issue is indeed temperature related more so than anything else. maintaining a constant ambient temperature. in the sixties (or close to it) will extend the life of either tubes or Ss amps... and they can be left on forever.
Other considerations do play parts though too. As was mentioned, controling power surges & spikes or brownouts is important for sure.
In the military we left much of the electronics on continuously... operating in a very cool ambient temp. I don't recall a tube or SS component failure of any great significance. periodic cleaning and testing of the tubes were the only prerequisites. We tested different tubes at varying intervals. outputs were once a year.
Leaving equipment unattended and powered up indefinitely in one's home however, could well be a problem just waiting to happen. Common sense is required to protect one's investment. We don't all have pockets as deep as the Govt's. I believe that's the variable which forces us to be more conservative thinking when we see the 'always on' OR 'as needed' powering up debate.
If you are going to use it routinely, can control the environments temperature, invest some time to periodic cleaning, and testing of the tubes at given intervals, as well as attend to verying power insurgencies, leaving it or them on is not a problem affecting greatly the life expectancy. Electronics do seem to enjoy a steady state of electricity more so than an intermittent one.
In either case though, just how long a thing will last, or if it will last longer is more predicated upon the topology and build than these other factors.
All that being said I've got a receiver I've had now for 8+ years. For nearly a year it was shelved and kept off. otherwise, I've used it nearly everday, and certainly each week at least. I turn it on as needed. it just went into the service center for a repair. An IC chip was the issue... not caps or transformers. The IC being replaced apparently had something to do with regulating power to whereever and as needed for startup. it was popping shortly after initial power up, and might have damaged the speakers if left alone. Reportedly, it is OK now.
According to some makers of amps, eg., Odyssey, it is recommended they remain on 100% of the time. For the most part mine does. Although I do have to shut it off now and then when reconfiguring other things and it does take more than 30 mins to get back to acting right again following powering down.
BTW.... I've an older PC that is 10 now, and only goes off during a lightening storm. it's working fine, and requires only a clean install of the OS about once a year.
Concerning solid state equipment, there have been endless discussions of this question over the years, concerning audio equipment, computer equipment, and all kinds of other electronic things, with no definitive answers, even among electrical design engineers (I am one, and I've discussed this question with others).
My own feeling is that the answer will be dependent on the design of the particular item, both the circuit design and the characteristics and quality of the particular parts that are chosen. Doing an analysis to definitively answer the question even for one particular design would be a formidable task, and could only be done if complete documentation on the design were available.
My bottom line suggestion for solid state gear is simply a common sense one -- if you use it frequently (e.g., two sessions or perhaps even one session per day) leave it on all the time; if you don't use it frequently turn it off.
Bigbucks5: electronic fail when you turn it on when it's not designed properly. You can turn on and off electronics thousand times a second for years and nothing will happen.
Blindjim: Odyssey and others recommend keeping it on because it takes a while to get optimum sound and not for the longevity. If it takes often days to warm-up, as Odyssey says, then keep it on but if it takes only half an hour keep it off since speakers require about the same playing time to warm up. Odyssey even stated that if you don't mind waiting for optimum sound then you can turn it off when not used.
PC is different story - whole idea of kepping it on initially came from mechanical stress on hard disc during start. Now they keep them on because maintanance is often done thru the network.
Given the question at hand was not about longevity, and rather, the need to remain on only, I thought to throw that Odyssey tid bit in too.
The Stratos SE amp only takes a couple hours or so of being re-energized for there to be no discernable diffs. I use it now, strickly as an HT amp anyways, so it sits at rest 90% of the time... though it is powered up and supplied by a RSA Haley power filter.
Tubes I use as needed. Another owner of the same preamp as mine said to get better sound, "Leave it on"... I tried that a couple times and found either little or no difference after a few days of being powered up, so it's on only when needed now... about an hour prior to playing some music. A half hour of music and then I'll take a seat and listen.
I do the same thing with the HT rig too... though for about half the time spans, 20 on & 20 more with signal.
The FPJ does not like to be left on at all, so as it's switched at the wall, I'll hit that too just prior to use.
I'll still agree however, if the conditions I posted above can be met, keeping things on will help extend life expectancy and reduce failures. Albeit, the costs of ownership are increased.
Bigbucks5: electronic fail when you turn it on when it's not designed properly. You can turn on and off electronics thousand times a second for years and nothing will happen.
That's so much BS. I guarantee that ANY electronics will have a much higher failure rate when turned On/Off vs leaving it on.
You can leave electronics on for 20 years and no failures. But try turning it on/off every day, and you'll never get close to 20 years out of it before it fails. Power cycling is always worse than not power cycling, regardless of how it is designed. Sure, the better the design the better it will tolerate power cycling, but it is always worse than not cycling.
I guarantee that ANY electronics will have a much higher failure rate when turned On/Off vs leaving it on.
Your guarantee is a considerable over-generalization at best.
For starters, your guarantee totally ignores how often the equipment is turned on and off, how long it is left on when it is on, and how long it is left off when it is off. Your guarantee also evidently extrapolates from your experiences with certain equipment to all other possible equipment designs, part qualities, usage patterns, and environments, which is, to use your term, "bs".
All electronic and electromechanical parts, whether resistor, capacitor, inductor, transistor, analog integrated circuit, digital integrated circuit, relay, even printed circuit boards, have finite MTBF's (mean time between failure) if left on all the time. The MTBF is typically non-linear with the age of the component (i.e., older components fail more frequently). New components also fail more frequently, especially if they are not adequately screened and burned in by the manufacturer. As has been noted in some of the posts above, MTBF is typically temperature dependent, and will be shortened as operating temperatures increase. It will also typically be shortened due to the thermal stress of being powered up and powered down repeatedly, which is apparently a key basis of your statements.
As I indicated in my earlier post, an analysis that would balance and combine all of these factors for all of the parts in a piece of equipment, and define an optimum power-up/power-down duty cycle for even one specific design, is essentially an impossible task. Most of the responses above, including yours, are based on perspectives that just address a limited number of these factors, for a limited number of part types in a limited number of designs, and understandably don't present any quantitative trade offs.
As I said in my earlier post, as an experienced electronics design engineer I believe that the best approach (for solid state gear) is simply the common sense one of turning the system off if you don't use it frequently, and leaving it on if you do. If like many of us you are somewhere in the middle, and use the system neither very frequently nor very infrequently, then you won't be going very far wrong with either approach.
Blindjim: Yes original question was about longevity - read again
Bigbucks5: I don't know where you getting your information. Electronics that stays on is also constantly switched - electrolytic cap are geting sharp spikes of current, switching power supplies as wel as class D amps constantly switch on off etc. Rush current during power-up doesn't do anything to SS electronics.
Almarg: semiconductors, resistors, capacitors etc don't have MTBF (not in our lifetime). They operate practically forever (except electrolytic caps). LED diodes might loose brightness over time (structure recombines itself to non-emmiting junctions) but it's not a sudden failure and it takes probably 20 years for this to even notice.
People got impression that SS gear will fail most likely during power up/down cycle because of previous experience with tube gear, relays, switches, bulbs, hard disks etc.
The only case I know where SS electronic gets "tired" is with very high power SCR devices (thyristors) switching few hundreds of amperes and it takes very long to fail.
semiconductors, resistors, capacitors etc don't have MTBF (not in our lifetime). They operate practically forever (except electrolytic caps).
Not true at all, unless you are referring to a single part operating by itself, which you are not. The combined mtbf of the hundreds or thousands of semiconductor and passive devices (even excluding electrolytic capacitors) in a typical sophisticated audio system will be measured in decades at most, and quite conceivably in years (less than one decade). That is especially true when you consider the sharp increase in failure rate that occurs with older components, according to accepted reliability models, and is even more true when you consider that many amplifier designs intentionally run semiconductors at high junction temperatures in the interests of improving the sound quality.
Please take a quick look at some of the 205 pages of MIL-HDBK-217F, linked to below, which is the guideline document for reliability calculations for military systems. Note that it addresses just about every conceivable type of electronic component. And keep in mind also that these are typically components that are manufactured, burned in, tested, and screened vastly more rigorously than anything in most consumer audio systems.
All 'lectronics is subject to failure. The metal interconnects used in ICs and discrete devices 'moves' under the pressure of the flow of electricity. The break will usually occur when the line goes over an edge, where the metal is thinnest and current density is highest.
When we (my company) introduces a part, especially a new technology/revision, part of the specification includes Lifetime. Parts are put thru a rapid aging cycle while under electrical stress. 1000 hours is typical and an industry standard. There is an accepted rate of failure, usually highest at lower hours.....so-called infant mortality.
That being said, I have never had a SS failure...cap, resistor, I/C, discrete device. My old amp was on as continuously as possible for 20 years. Other stuff switched as needed.
My company makes a line of 'HiRel' and some of our stuff even finds its way into output and power supplies.....and makes full-on class 'd' modules.
Everything has a MTBF, even if it is a HUGE number.
I personally count on Infant Mortality of new equipment. Do a run in for a couple weeks and call it good.
Doesn't current surge, the first 1/2 cycle to saturate a transformer count as stress?
"Doesn't current surge, the first 1/2 cycle to saturate a transformer count as stress?"
Yes it does create rush current - but there is no evidence that it shortens life of electrolytic caps. It does nothing to transformer or rectifier.
You won't fint MTBF on any datasheet of any transitor, diode, IC (digital or analog) etc. - probably because it is in order od few hundred years. The question was if switching on/off is shortening life compare to keeping it constantly on - it doesn't. It will shorten life of switches, relays, tubes but not the SS stuff.
You won't fint MTBF on any datasheet of any transitor, diode, IC (digital or analog) etc. - probably because it is in order od few hundred years.
Yes, but when you combine hundreds or thousands of devices into a system, the several hundred year mtbf of an individual device essentially gets divided down by the number of devices (with each device receiving greater or lesser weight in the overall calculation depending on its individual mtbf).
There is an entire branch of engineering that deals with this, known as Reliability Engineering. MIL-HDBK-217F, that I linked to above, provides an inkling of how involved it can be.
Almarg - when you have hundreds of thousand od devices you increase chance that one, or connection between them, might be faulty. If number of devices should decide alone on reliability then Pentium processor that contains milions of transistors should fail every day. What about system that contain thousand of Pentiums - it should fail constantly.
It is not even relevent to audio gear that contains small amount of components. Stress done to wires inside of IC caused by current flow cannot be that bad since we have some of ICs working (and often in bad environment) for about 50 years (and first ones were poorly made).
If you believe that SS amp is more prone to failure from switching on and off - please tell me what fails!!!
(Don't count cases when you turn system off to modify something - like shorting speaker wires and then turn amp on again with failure.)
Kijanki -- I was NOT one of those who said that a ss amp is more prone to fail if switched on and off -- please re-read the posts I have made in this thread.
Audio gear does not contain a small number of components. A typical high-end system will contain hundreds, and perhaps thousands, of components, especially if you include passive components such as decoupling capacitors (not electrolytics), resistors, etc.
One of the fundamental advantages of integrated circuit technology is that it is integrated, meaning that an integrated circuit containing millions of transistors will have VASTLY greater reliability, and longer mtbf, than a circuit containing a corresponding number of discrete transistors.
A supercomputer containing thousands of Pentiums WILL experience failures somewhere in the system almost constantly, perhaps daily, and a great deal of thought goes into their design to provide redundancy that can overcome the low overall reliability.
If you do not, or will not, understand the concept that system mtbf is reduced as a function of the number of devices in the system, I can only tell you that you are wrong and you should research the matter further, including in MIL-HDBK-217F.
Again, I did not say, and I do not believe, that a solid state amp is necessarily more prone to failure if switched on and off regularly. In fact, most of my previous comments are probably closer to being consistent with yours than most of the comments posted by others in this thread.
Almarg - Supercomputers don't fail daily, otherwise we would have serious security problems (unless you talking about software crashes). Audio gear does not contain thousands of components - give me example of one. You will be lucky to find one that contains couple of hundred.
What is interesting about electronics commonly used is that if it does not fail in the first year most likely it won't fail for next 20 years (just opposite to MTBF) and when it does it's usually because of lightning or mechanical failure (switch, relay, motor, plug etc).
Hard discs that have MTBF in order of at least 5 years have 99.9% of time mechanical failure in spite of having a lot of electronics (ICs) on them.
MTBF does not apply to audio gear and probably should not be mentioned (unless we try to predict statistical failure in 500 years). Remember saying about lies big lies and statistics? Statistics already has proven that motorcycle accidents are caused by tatoos.
Kijanki -- What I meant about supercomputers was that a failure will occur somewhere in the system frequently, perhaps daily, but the systems are designed with redundancy that allows them to continue to function despite the failure, and while the failure is being isolated and repaired. In fact I believe some of them have associated diagnostic computers, whose only function is to detect and diagnose failures.
When I mentioned hundreds or possibly thousands of components, I was referring to the system as a whole, not to any one individual component. And I was including capacitors, resistors, etc., which these days are very small and can be very numerous.
I don't have schematics for any recent audio components. To some extent I'm extrapolating from my knowledge of computer motherboards, which typically contain zillions of tiny components and are probably somewhat indicative of the digital, microprocessor-based, parts of many modern audio components. But besides that, if you have ever looked under the chassis of a quality analog FM tuner, new or old, you will see many hundreds of discrete components. The ultimate example is probably the Marantz 10B of the 1960's, which I have seen the underside of, and it contains more components than I would want to count.
Your comment about not failing for 20 years or so after the first year is exactly what I was referring to earlier about failure rates being non-linear functions of device age. Failure rates are greatest during infancy and old age. They are much lower during the period following infancy and through middle age. That is well recognized in Reliability Engineering. But my point is that the relatively low failure rate during middle age can still be significant, because it will be degraded at the system level as a function of the number of devices (and potentially also by many other things, such as operating temperatures and the specific circuit designs).
The quote about there being lies, damned lies, and statistics, was actually originated by Mark Twain, and is one of my favorites. I hadn't heard the one about motorcycle accidents before -- good one!
Almarg - I'm not clear on reliability and you can probably tell me where I'm making mistake but if we take device like transistor that eventually fails (everything fails) - let say in 100 years then using 1 milion of them would cause earlier failure, and in case of 1 billion of them one would fail every hour - am I right so far?
Now I have pencil on the desk in front of me. It doesn't last forever and will eventually rot - let say in 100 years (used or not). So if I take 1 milion of similar pencils one would rot in an hour after it was manufactured?
Doesn't reilability engineering assume that there might be some (very rare) faulty components (or connections)?
People believe in proportionality and therefore everything has to fail some time but for instance life of steel under stress is infinity of cycles (no fatigue) as long as strees is below certain level (not true for stainless steel and other metals).
Imagine basketball with a rope around it. Add 1m (3 feet) to it and rope will be loose by about foot everywhere (radius increases by 1 foot). Now do the same with our earth around equador, add 1 meter and you'l get axactly same result - gap of 1 foot everywhere around the earth.
r2-r1=(L+1)/2pi - L/2pi = 1/2pi L disappeared. It is very strange and counter intuitive but has certain practical implications. For instance clothing sizes for children cannot be in the same numbering scheme/scale as for adults.
Kijanki -- Good questions.
I don't want to get into non-electronic things, because I'm not particularly knowledgeable about them.
But consider a transistor or integrated circuit. Envision a plot of failure rate vs. component age, based on the assumption that it is being operated within its specifications (not always the case). A plot of failure rate vs. age will start out at some relatively high value (infant mortality), which in turn will depend on the degree of screening, burn-in, quality control, etc. (which is better for military gear than for consumer gear -- one reason consumer gear is so much cheaper). The curve will then go down to a lower level following the infancy period, and remain relatively constant until old age, when it will rise considerably.
What is most relevant to the questions we have been discussing is the middle period, where the failure rate is lowest, and is fairly constant over a considerable number of years (as you have pointed out). If we consider only that period, where the failure rate is essentially constant, then yes, if that failure rate at that point on the age curve is, say one failure per 100 years, and we have 100 components of that type, then we can expect one of those components to fail each year, on average. One set of 100 components may do better than average, and last 5 years without a single failure. Another set of 100 components may do worse than average, and have a failure within a month. But averaged across a large number of sets of 100 components, there will be 1 failure per year per set, based on the assumptions of constant linear failure rate, mtbf of 100 years, and 100 components.
If the failure rate vs. age curve is not linear and constant, such as during infancy and old age, the analysis is more complex. And as I indicated earlier, calculation of system mtbf has to take into account and properly weight the mtbf's of the different types of components, as well as their relative quantities in the system.
Hope that clarifies things more than it confuses them!
My system consists of a solid state cdp, solid state amps, and a tube preamp. I usually end up listening to music almost every night when I get home. Is the general consensus that I should keep everything except the tube preamp on at all times due to the high frequency of usage? My tube preamp is actually from Odyssey and the guy from Odyssey said that his co-worker's tube in the same preamp has lasted a year and a half so far and that it has yet to be turned off.
The original questions was: "Should an audio system be left on at all times?" I think a more appropriate question would have been "Should an audio system be left on at all times to enhance performance during each listening event", or "Should an audio system be left on at all times to increase longevity"? Frankly, I don't really care about the latter.
For me, it is all about whether my system sounds good when I sit down to listen in the brief windows of time my current life affords. If leaving my source and amp on all the time in order to shorten warm-up period for listening is a valid concept, then I will do that. If not, then I am just wasting electricity. I did not buy this gear to have it sound less than optimal for a period of 30 minutes to several days each time I sit down to listen over many many years. If it breaks, I will replace it with something better.
Is the general consensus that I should keep everything except the tube preamp on at all times due to the high frequency of usage?
I'm hesitant to declare that we have a general consensus. But in terms of reliability I would say the diversity of opinion we have seen is consistent with the opinion I expressed that, considering your frequent but not extreme usage patterns, you won't be going too far wrong either way.
In terms of sound quality, optimal warmup time is going to be system dependent, and probably listener dependent as well, so if you choose to have your system off during the day see if you notice continued improvement in sound quality following whatever warmup period you choose to use initially.
Perhaps this is a bit of an anticlimactic conclusion in view of all that has been said, but I think that any conclusions beyond these simple ones are unprovable, are probably not universal, and in terms of longevity probably don't make a lot of difference anyway.
Complex systems fail more often then simple stuff....like hammers. Failures can be simple or complex. Also, complex systems are LESS fault tolerant than simple systems.
Complex, integrated circuits....Pentium is a fine example....
are subject to failures caused by heat and electromigration.
Electromigration is when a conductor 'crawls' under the influence of flowing current. Conductors ALWAYS fail at the point of thinnest metal, usually over a 'step'.
Also, complex systems are LESS fault tolerant than simple systems.
I'd add the words "everything else being equal" to that statement. The complex system might have redundancy and fault tolerance designed into it, while the simple system might not.
And I'm not certain that the statement is true even with that qualification. For instance, if anything in the signal path of a very simple amplifier goes, the system doesn't work.