Leaving my amplifier on ok?

Would it be ok to leave my amplifier on all the time if I want to extend the reliability of the amp? Many amplifiers ar Class A, high current bias and tubes might be a problem if energy consumption is a factor. Not to mention Excessive heat from bias operation. Is it possible to extend the life of the amp with leaving it on all the time?

Ag insider logo xs@2xhighend64

There isn’t a electronic component that has its life extended by being on all of the time.  Amps, in particular, have a shorter life from being left on because of hear.  Tube gear should not be left on because there is a limited life to all tubes and that life is primarily determine by how long the cathode of the tube has to emit electrons.  The only reason to leave something on is to reduce warmup time.

I run Hegel amps and wondered the same thing after reading so many different opinions.  Questioned Hegel directly and was told to turn the amps off when not in use.  They said leaving them on only shortens the life of electrical equipment.  I listen to music every evening and turn the system on about two hours in advance.  

Use "search discussions" above, where topic has been discussed, at length.

For solid state amps: best to leave "on", all the time, if you listen frequently. This reduces "thermal cycling" of the circuit board. 


@pmm +1! If Class AB they can run 24/7. Power supply caps will stay warm and nicely formed. Class A amps that run hot should be turned off when unused.

In the old days caps were not nearly as reliable as they are now, so frequent on/off surge cycles were bad.

They are much better now and it's no longer worth keeping an amp on all day, due to the other aging factors.

Some Class D amps (IcePower especially) from being left on for 2 days or longer before listening, but thanks to the efficiency it's not nearly as taxing on your budget or the planet.

And no, no Class A amp should be left on continuously.

Sorry, to clarify I meant:

Some Class D amps (IcePower especially) BENEFIT from being left on for 2 days or longer before listening,

All components have a rated life that includes the life at different operating temperatures.  It is always the case that higher heat means shorter life.  If an amp is run constantly, mostly at idle, I would hope that it is designed such that heat would not be excessive, but, in any case, that heat and constant use would not increase the remaining life.  It is particularly the case that heat as well as constant operation would not be good for transistors.  As for thermal shock affecting PCBs, I have my doubts that normal turn on and off operation would not have a meaningful impact on life of boards, and would be interested in information demonstrating otherwise.  PCBs are tested for thermal shock vulnerability, but testing conditions are quite extreme (like -40 centigrade to 100 centigrade), not the kind of conditions found in home operation.  Boards are expected to last for at least 50 years.

Electrolytic caps do sound their best and are well preserved by being kept charged, so there may be some benefit there to keeping an amp on all of the time.  But, they too are subject to shorter life from higher temperatures, so, some sort of tradeoff/balancing is involved there.  The big issue with leaving electrolytic caps in a discharged state involves many years of storage in such state--it is not really an issue as far as a few days or even months of non-use.  But, sound quality is another matter.  Some gear takes a long time to sound its best even when warmed to full operating temperature because the caps are not fully charged/formed.  For example, NAIM recommends leaving their streamer on all of the time because it takes the caps almost a whole day to be at their best from a cold start.

The other safety/reliability issue has to do with power surges from electrical storms and brownouts that may occur while one is not at home and able to turn off gear.  I have not heard of many instances where gear has failed and caused a fire, but, that too is a (remote) possibility.  

When I ran solid state amps, I kept them on all of the time, except when I left town.  I knew this involved some risk and shortening of the life of the amps, but, I accepted that to avoid a warm up period.  I now run tube gear, which MUST be shut down when not in use to preserve tube life, but then again, tube gear tends to sound quite decent after a relatively short warm up period.  I can enjoy the sound, even if it might not be at its very best, within five minutes of turning on the amp and linestage.


Maybe dumb question but do you mean "on" as in ready to operate or in "stand by" mode?

I ask because I typically leave my H390 in stand by mode. If this not recommended, I’d like to know.  



My PS Audio amps are designed to be turned off using the front buttons while keeping the circuit warm as long as the back buttons are not turned off. After turning on the front buttons warmup time only takes about 20 minutes.

True components that produce a lot of heat are subjected to greater stress on their components but a well engineered component will be designed to handle the amount of heat it generates. It’s the constant stress of on and off cycles cause the most stress on a component leading to failure. 

After reading so many differing opinions on this subject, I asked the manufacturer, in my case Hegel, if there was any harm caused by leaving my H30 Mono amps powered on 24/7, and is the rush of current at startup more harmful than constant power. Their answer was this. The amps are not damaged by the on/off cycle. They recommend waiting 60 seconds between turning on, if you have turned off. They did advise against leaving powered on 24/7 citing a waste of electricity and shortened life span due to constant heat. Therefore in my own case, I turn off after listening and turn on a couple hours in advance of my next session.

Maybe someone could answer this question for me. Define "shortened" lifespan. My previous Parasound power amp lasted 20 years without any issues and then I sold it. If shortened lifespan means lasting 25 years instead of 30, then I’m now too old to care as either one will out live me.

Is your amp Class A?  If so the answer is obvious unless it has a low bias switch (like Plinius SA103, some Clayton amps, etc.).  I recently had my McCormack Class A/B amp upgraded by SMcAudio and Patrick told me I probably extended the life of my amp several years by leaving it on 24/7 (I only turned it off when we left for week-long family vacations).  My amp worked fine for 30 years this way with nothing more than a blown fuse along the way that was easily replaced.  Plus, my amp was always warmed up and ready to go immediately, which was nice.  I mentioned to Patrick the reason I left my amp on was from anecdotal evidence that light bulbs almost always blow out when you turn them on, and he thought that was an apt analogy.  SMcAudio believes in this so strongly that when you upgrade the amp they disable the power switch that becomes nothing more than a dummy switch that controls nothing but the power indicator LED (they said so the wife/dummy knows it’s on — heh heh), so as long as the amp is plugged in it is always on.  Given my personal experience and that Steve McCormack kinda knows what he’s doing I just thought I’d share FWIW. 

Thanks for all responses! Some of the posts I do agree with stress on components and also turning on and off on certain amps. Logically, keeping electrical components like capacitors in PS keeps charged in a steady state.

You can always compromise and turn amp on before going to bed Thursday night (for a big weekend listening session). Turn it off Sunday night.

I read an unbelievable story about a NYC dweller who left a pair of McIntosh monos on for 35 years because he had them in an impossible-to-reach location. Maybe I dreamed this...

@dweller , that story rings a bell. I have read that too. But it was just that this dealer or reviewer was helping out a widow whose husband had died and was buying the amp from her. The best part was that the amp sounded fine even with the tubes being ON for that long. I believe it was in Stereophile somewhere?

I have  five amps I use every day. There are 4 d amps that I leave on 24/7. Also in use is a single-ended 812 amp, that is in use most of the time (cuz it's so good!)  There is an SET 300B that is used rarely (it makes a good back up when necessary).



@highend64 seems to have already answered his own question.

Anywho, here’s my take. Give the ones that generate heat room to breathe. Chances are all will be well.


When we think we are turning off our Hegel’s we are actually turning them to standby and that keeps the Caps charged up. It’s also the reason we don’t have to wait but a few minutes to hear the best sound from our rigs. 
Now something I tried to get an answer from Hegel is, how many watts of Class A does the H390 put out before the class B kicks in. I never got a straight answer.

@curiousjim  You are correct about the standby mode in many of the Hegel amps.  Unfortunately,  My H30's don't have the standby option.  It's on or off and nothing in between.  

In general for tube amps it's better to turn them off. With one exception that I know. David Berning's amps. David designs for long life, very, very long life in total contrast to almost every other tube designer. I know from a friend who was there that David's first amp , the Audionics BA150, would last almost forever. The prototype was turned on in 1972 and turned off in 1977 and there was no measurable wear on the output tubes.

I can recall reading from more than one amp engineer designer talking about this subject. Yes caps are built better than in the past but they all agreed that the greatest factor to cap failure was not as much the excess heat as much as it was the constant hot cold cycle. Their claim makes sense to me as a hot cycle expands and a cold cycle contracts and this constant cycle of expanding and contraction is the cause of cracks forming that would lead to failure. Another is my real life experience with my sansui 7070 that I purchased in 1979. I moved this into my wife’s salon to run music in her business. Outside of power outages the unit has not been turned off for 30 years and it is still going strong with no issues. I will agree you do not want to leave tubes in biased mode as they have a defined life cycle. My current amps I never turn off.

Question was presented to a McIntosh tech some years back.

The response was a resounding NO. If it’s on its being used and any piece of equipment  being used does not have its life span increased by being used.

It is not so much heat/cold cycling that damages caps as it is the rapid inrush of current that deforms the cap.  But, any decent designs where this could be a problem would include a “soft-start” circuit that puts a high current resistor or a resistor that has high resistance when cold in series to reduce inrush current until the cap has been gradually charge to the point when a relay (usually timed) closes a circuit that allows full current flow.  Turn onTurn off cycling should not reduce component life (except for failure of the soft-start relay which is a common failure mode).  

I find that my Class A solid state mono blocks sound better after 96 hours. They run at body temperature. There are no electrolytic caps in the mono blocks to dry out. The power supply is in another room, where the electrolytic caps remain at room temperature. So I turn them off for heat domes, not otherwise.

Ain't DIY great?

Standby mode is good to use saywhen nolongerlister8ng for the evening 

warm uptime is maybe30 minutes to sound best..


Audiogon forum opinions are like stock market opinions, for every opinion you can find the exact opposite...mine is, for SS, especially if there is a standby mode and slow power up(like Pass X250.8), turn off on front, leaving it in standby...the sound is better when warm, but that doesnt take a terribly long time.....

I let my Sansui alpha S.S. amplifier "on" all the time...

Why ?

Because i dont like the switch button working at all...It is the only thing i can fault about this amp...

The amp never become very hot anyway with headphones and always ready... I read many people experienced long time working of amplifier which are always "on" and no problems... And i trust soix experience .. 😊

I hate the button way of working with a scintillating light for 20 seconds indicating it is ready...For sure it is a relay protection time and it is good... But i prefer not to touch it... And my amp is always ready...I listen music each day at least 2 hours...

My sound quality , it is ectasy each evening, is so good i did not know if i will not coming back to listening few time after beeing switch "off"... It is very hard to stop listening... Then i prefer it ready...

Anyway i am already 72 years old... If it let me down after my death because of that habit i dont care.. 😊


Speak to your Home Insurance and Amp's Manufacturer.

I'm sure the Insurance will happily payout for electrical fires when a Fridge or another White Goods or the like has a malfunction that results in a fire, and there is plenty to suggest it has been cared for as the Manufacturer Suggests. 

Taking advice of a forum on such matters of such unimportance can easily leave one without a home and no Insurance Payout to boot. 

It is the individual holding the insurance policy, who has a responsibility to act in accordance with how the Insurance Company deems good practices are being followed. Unpaid claims are regularly found in conjunction with abnormal practices. 

Leaving Laptops 'Permanently' Charging and then unattended, is known as a cause of fires in premises', the Insurance Companies are known not to pay out when this is a cause of a fire. 

Today leaving a Laptop Permanent Charge, might not be considered abnormal to the regular user. Leaving it unattended whilst charging for a excessive period is probably normal for many.



I have never heard of an insurance company not paying because of the reasons you state, do you have some examples?

Further, I’ve never heard of an audio component bursting into flames and causing a fire.  But whatever. 

Since the argument against leaving your SS amps on 24/7 is the damage caused by heat (mostly), what is the temp of your equipment both when in use and when idling?  At Idle, my Hegel H30 measures +/- 90F on the warmest part of the case and 100F is the warmest temp I can shoot inside the case.  When in operation, both go up about 10 degrees F.  It would seem my equipment would suffer more heat damage sitting in Pheonix completed turned off.  

The other concern is electrical storms, odd power fluctuations, etc., and not being there to shut down until the situation is over.  Still, when I ran solid state I did leave the electronics on all of the time to avoid warmup issues (I still leave my server on all of the time for this reason).

I did have a carver receiver go up in flames, but it only lasted a split second, and unless there was a lot of paper and kindling on top of the receiver there was no chance of a fire.

First, yes, there are many older posts that discuss this topic at length.  However, the OP asked a question and is requesting help, not a scolding for not reviewing prior posts.

If you don't want to help, then don't answer. 

Second, most new components have soft start circuitry that dramatically reduce the inrush and damage to components.  So this shouldn't be an issue with newer components.

I have yet to hear any high end system that didn't sound great after about 45 minutes of warm up.

There are so many golden ears out there.  But really, your system sounds like crap even after an hour of warm up?  really?

If you aren't concerned about tube life, then leave them on 24/7.  Just remember, sometimes with heat and leaving on, when they go, they really go spectacularly, and may take your home with it.

I never leave my system components on.  When I want to listen, I turn it on, do some other things, and then after a warm up period settle down and enjoy.

Most manufacturers won't recommend leaving they devices on 24/7.  Some low powered stuff may be okay.

I have some pretty decent tube gear and power tubes typically last 2000 hours and are really expensive.

I've had an amp or two launch a tube or two with resistors and other circuitry.  Not fun and thankfully I was home.

I have a Krell KBS balanced crossover made specifically for my Martin Logan Monolith III speakers that is always on, no power switch.  Which I believe is really stupid.  Some components went up in flames.  So, subsequently, after repairing it, I unplug that sucker most times until it is needed.

But, it is up to you.  Listen after an hour or so warm up.  Then listen after 24 hours of it being left on.  Hear any difference?  Of course you have to go by memory on this one.

There you go.


Looks like what I stated, and the few responses are in this limited space a case of s 'pearls before swine'.

As stated, the MANUFACTURERS Recommendations are the only ones worth seriously considering, and are the ones that will be investigated by a authority, especially a Insurance Company at the time of a Claim, if the device is the cause of the claim.

What is thrown around on a forum is BS to these types, they will not be looking for any advice in such a place. 

Hence, "Speak to your Home Insurance and Amp's Manufacturer."

I switched off all my gears when they are not in use, not even in standby mode. 

I think a good setup needs to sound very good even with little warmup. I would turn on my setup, let it warm up for 5 minutes max, and immediately enjoy aural bliss. I don't think a setup should sound drastically that different with longer warm up. If it is, perhaps invest in better components?

MANUFACTURERS Recommendations are the only ones worth seriously considering

Good point.

I have had some manufactures advise to "leave on" ss components, and to "turn off", when not using for a while.

Most modern designs are going to have a standby mode where the component consumes very little power. Usually .5 watts or less.  It’s pretty apparent that they are intended to be in standby mode when not in use.  I noticed even holdouts like Naim have finally embraced energy conservation and have this feature in the new classic line and statement amps.  
Older designs without a standby mode I can’t really say.  I have owned amps that consume 20 watts or more at idle. That can add up over time so personally I turn my stuff off. But I’ve never owned a mega expensive amp, so my experience may not be applicable.  In this industry there are many specious ideas that are spread around, shared and reinforced. Stay skeptical. If you’ve got a really expensive amp, and want it to last decades, try calling a service center to get opinion. 

most new components have soft start circuitry that dramatically reduce the inrush and damage to components. So this shouldn’t be an issue with newer components.

@minorl Even if that’s so, which you’d need to confirm with the manufacturer, the point you’re missing is that the constant temperature fluctuations between cold and warm/hot also degrade electronic components faster — this according to Steve McCormack.  I’d refer you to my prior post for more context if you haven’t read it already.

My 'go to' Audio EE, who has designed and built a selection of my systems devices, and carried out circuit corrective works on another owned device.

Made it known to me in the very earliest days of out relationship, to always have eyes on the devices in use, to Power Off after use and revisit shortly after Power Off for peace of mind.

This is a discipline maintained to date, which was first strongly suggested over 25 Years ago.

This advice even though extremely valuable, is seemingly the anti-thesis of the description being given of how another EE is endorsing certain paractices.

On the matter of early component failure being realised through heat fluctuations is surely a case of stepping over $'s to pick up Cents.

I lost my home due to an electrical fire occurring, as a result of being foolish and try to prolong the life of a devices components that might only cost a few cents to replace once spent.

All Cap's, Resistors, Switches are going one way, and that is spent as a usage life. Ask a EE.  

@soix, Thanks for the information.  I don't believe that it is a constant temp flux, because one isn't turning on an off like a 3 year old.  It is turned on and let warm up.  Hence the word warm up.

however, I appreciate your input and will look at your other post/responses.

any good information can't hurt.



@minorl I think I kinda misspoke — I meant that every time you turn your system on the temp of the internal electronic components go from cool to warm/hot, and then when you turn it off the reverse happens.  This is the temperature fluctuation I was referring to, not some constant fluctuation during operation.  Just wanted to clear that up and sorry for the confusion. 

1) Valve amps should not be left on since the life dependancy of the tubes
is affected.

2) Class A amps should not be left on due to the wasted energy and heat
that they generate.

3) The rest depends on whether your amp has an inrush current limiter or not.
- If it does (your lights do NOT dim when you switch it on), then turning it
off would be ok.
- If it does NOT however (your lights DO dim when you switch it on) the
amp should be left ON all the time since considerable stress occurs at power up.