Warm-up time for amps and preamps

Yes, frequent switching on and off in some ways can be more detrimental than leaving the amp permanently on. It depends on what components we are talking about as capacitors or transistors of certain amplifiers can last very long, well over 20 years before a degradation of sound quality is perceived. Naim recommends their solid-state amplifiers to be left permanently on, and the recommended service is every 10 to 12 years for the amplifiers and power supplies.

It may not be recommended to leave tube gear permanently switched on but some solid-state gear are designed to be permanently on without much adverse effects.

All my SS gear is on 24/7 unless aim way for a couple of days. The amp is in stand by unless i am using it.

Small preamp tubes last longer if kept on as the turn on surge etc... shortens their life. Depends on build design, but I have owned tube preamps where the designer told me to keep the unit on unless traveling for best sound and tube life. The amp never got hot and the parts and tubes were cozy warm for long life and wonderful sonics. 

Not all SS amps are created equally.  As an example, my Gato AMP-150 has a warm up feature as they have determined that it takes a full 2 hours of operation to achieve optimum conditions.  With this warm up feature, it takes only takes 15 minutes. 

The "correct" answers totally depend on what you are trying to achieve. 
If you want superior sound quality and don't care a lick about the life of your components, then by all means leave the equipment on 24/7.

Most tube equipment manufacturers will tell you in the owners manual that leaving the equipment on will significantly degrade the life of the tubes.

if, you are like me and own tubed power amps and tubed pre-amps, then you get what you pay for.  I don't look forward to replacing my power tubes every 2000 hours, and since I have a policy to not leave equipment on when I'm not using it (refrigerator aside), then I turn them off.

Unless the equipment has some sort of low power usage standby circuitry, the life of the tubes will degrade quickly leaving them on.

Take for example, my Audio Research REF 250 (not SE) amps.  Audio Research told me that new tube sets for the amps are $1,030 for each amp.  Well, that is an expense that I'm not looking forward to, and will not hurry this expense. 

For my Mark Levinson 23.5 amps, well, they get quite warm and replacing the capacitors and other components is quite expensive.

Heat not only quickly degrades the power supply capacitors, but also degrades the heat sink compound used on the power transistors.  When this stuff dries out, it is a problem.  When I upgrade or just routinely service ss amps, I remove each power transistor, test them to see if they are still operating within spec (many do not over the years), and replace them when necessary, along with all the mica insulators and heat sink compound. 

Anyway, if all you care about is superior sound quality and don't care a lick about life of components, then leave the equipment on.  but, think of it this way.  Do you leave your TV on 24/7?  What about the lights?  No, you turn them off for a reason.

You don't want your house to burn down when you aren't there.

My system sounds great after about 30 minutes warm up.  So, I plan ahead and turn the system on before I listen.  Then I turn it off when down.

But, that's me.

Enjoy

How long does it take for your system to sound good from a cold start?
I try to keep my system on most of the time. But occasionally I turn it off and it sounds like crap for a good half-hour to an hour.
i know there has been discussion here on the virtue of leaving tube preamps on all the time.
But my solid state amp (modified NuForce mono blocks) technician advises turning even them off occasionally.

Rvpiano,

I would say check with the equipment manufacturer/designer’s recommendation. If your ears tell you otherwise, then go with your ears. I leave my Naim equipment on 24/7 based on manufacturer’s recommendation. From my experience throughout the years, the Naim preamp takes 2 to 3 days to achieve optimal performance, the power amp takes several hours from cold. Most Naim users leave their equipment powered up 24/7.

As for my sources, I switch all of them off when I am done with the listening. The CD player has a standby switch and is warm to the touch when it’s on standby.

rvpiano 

Half hour sounds about right to me. 

Thank you, phusis!

SS gear sounds best when the unit is left on. This is the truth to my ears based on my experience with numerous amps over numerous years. Class D amps most especially. 

There is absolutely no reason why running without input signal would be bad for any class D amp.  This strange advice was given by NuForce technician?  Are they still in business?

I believe the above rests on a misconception; it is advised by NuForce not to turn on their switching amps without speaker load - that is, with the speakers disconnected. I imagine that's what's referred to?

Right.  The only exception is tubes.  ARC keeps track of the time on their tubes and puts that info in the display.

Properly designed electronics doesn't have components under a lot of stress.  There is a lot of industrial and commercial electronics that stays on for decades including home phones, elevator controllers, phone switchboards, cellphone towers etc. Pretty much all cellphones are on 24/7.  Failure is usually caused by external conditions (heat, mechanical stress, water condensation etc).  Test equipment, my company made in 70's, still works today after more than 4 decades of continuous operation.  

Fsilahua...Is SO CORRECT!!  as stated SS equipment has no warm up time.  As with tubes some equipment (not so much with audio) has a low voltage standby current that keeps the filaments warm so as to diminish the start up time when the equipment is turned back on. 

And contrary to popular belief, just because you do not "feel" the amplifier is getting warm, does not mean the buried components on the PCB are not under a lot of stress do to heat and current.  Components fail do to this factor, and to leave your equipment on 24/7 is ludicrous.  Yes there is voltage spikes, but the engineers have taken this into consideration, and incorporated relays in the rail voltage circuits, of most high end amps.  or surge resistors in the less than high end.

So go ahead run your equipment 24/7  the repair shops love you!!

Oops, premature send. I meant to end by saying that in many instances we continued to see visually represented change long after we believed we heard any additional changes.

10-15 years ago had a sound engineer come to my home and plot frequency response with MLSSA software, using test tones and sound level matched by meter. Repeated 5-6 times over the next 3 hours with the differences clearly notable on the visual graphing. Nothing subjective about it so far. Did those differences translate into different sound? Yup. Did I perceive those differences as qualitatively desirable? Yup. This on an all SS system left on 24/7, unless I will be absent for 2+ weeks. Just for the fun of it we repeated this on my and a couple other systems a few times. Same result without respect to components-visually represented differences in response over time, some more so than others, but none stopped changing within our 3-4 hour window of trials.

for the same reason that anyone here should have to exercise correct word choice - a question was asked and people are giving answers


as to how to test - you would want two copies of the same component - warm one up (w/o listening) for an hour or two and then A/B/X them

" How can you prove that what you hear 45 minutes later from the same source and media sounds any different?"

Why should anyone here have to prove something? If you don't feel its necessary to warm up your system, great. If others want to, that's they're business. Besides, its hard to find an owners manual that doesn't discuss warm up. What proof do you have that they're all wrong?

What are all you guys smoking? With SS equipment, it only takes a fractions of a second to reach stability, with tubes it might take a few seconds only! How can you prove that what you hear 45 minutes later from the same source and media sounds any different?

reality is your brain ......'psycho - acoustical' part takes longer than most of ones gear.  First half hour for your components, the second half our for the brain to 'accept it' !

I've got a Simaudio 700i amplifier and if I unplug it from the outlet it takes several days before it sounds like magic again.  Using the standby switch on the front panel only mutes the inputs and turns off the front panel display.  The amp stays just about as warm in standby as it does when it's turned on without music playing.  I've heard it draws around 70 watts or so in standby and 90 idling.  They must have a reason for designing it in this manner.  I never unplug it or use the rear panel AC switch unless I'm going away for longer than a week or so.

Tube should be designed with an "idle circuit" - if not, I'd wonder about the designer.

While heat can be a killer of electronic components, the real killer is voltage spikes.  They can happen from turn on.

Electrolytics from about 20 years ago or so are well known for some longevity issues.  Dunno if they changed the paste or what -- or if so, when...

I have a bel canto power amp.
Instructions say 40 hours for complete warm-up
from a cold start. So, I leave it on unless I leave town.
Any advice from those with bel canto experience?

Tube pre and power amps - turn on - warm up - turn off after you finish listening

Solid state - leave on 24/7 for best sound

Everything has a warmup period, regardless of what you do, when you start your listening period.

The higher the resolution of your system, the more noticeable the warm up effect.

I leave it all on, even my Lampizator stays on(read manual).  I turn them off if there is an electrical storm in the area or if I am leaving home for several days.  I've had some SS devices that take 3 days to really come alive and do what they are capable of.  Try it and hear for yourself, it won't hurt them.  If leaving it on is going to harm it, you don't want it anyway.

Leave it on for extended life in many instances. My Class D amp runs very cool so heat is not an issue. Small preamp signal tubes last longer on as studies and real life experience show. Turning the tubes on and off often reduces tube life faster than just leaving them on. As always it depends on the design with no blanket statements applying to all gear. 

I believe rvpiano said it best. There’s been lots of threads about this already. One member mentioned awhile ago that a SACD player needs to be on for about 2-3 days to sound its best. Others have stated that SS gear needs to be on 24/7 unless not listened to for several days to a week. As much as I listen, I leave it all on 24/7. Everything is barely warm, at best. In fact, I can hardly feel the difference.

All the best,
Nonoise

The designer of my tube integrated said that it's fully warm and stable after 15 minutes.  I'll give it at least 5 before starting any playback, and 15+ before sitting down for a listen.

My DAC/Pre (no tubes) stays on 24/7.

My office system has a Yamaha 2-ch receiver I bought in 1996.  I've only turned it off about seven times, ever -- and it still sings. 

There are many "authoritative" answers here.
i wonder which ones are right.

keeping your equipment on 24/7 is the best way I know of to decrease the life expectancy of your equipment, big time!  Heat is the killer of electronic components.  Heat is generated by tubes, high wattage resistors, high current output transistors etc.  This is why fans / heat sinks etc. are incorporated.  If you have ever looked at a PCB with high wattage resistors attached you will see darken areas where they are, plus cold solder joints forming.

The electrolyte paste in power capacitors, will dry out if just setting on a shelf or in equipment not being utilized.  Sometimes you can bring a electrolytic back to life by reforming it with a voltage source that is regulated.

Bottom line , to turn your equipment off when not listening is the best service you can do to your equipment.  But don't just let it set for months on end without operation.

All audio equipment electronically speaking, will be up to full reproductive audio response after a minimum of ten minutes.  Resistors, capacitors, diodes, solid state devices, etc. do not have a warm up period or break in time.  The only component that can benefit from time on is a valve tube.  because of the electrons boiling off the filament, increase conductivity with longer on time.

Tube equipment will begin to degrade over time do in part to an oxide coating that develops on the filament, not allowing for full conduction of the electrons to the grid and plate of the tube.

Everyone is basically correct here. Solid State equipment usually takes about 30-60 minutes to get warm and stable. Electrolytic caps don't like heat but like being charged all the time. Tube filaments should always be on for a at least 30s before HV is applied. Using tube rectifiers automatically fixes this issue as they don't put out any HV until they themselves are warm. This BTW does not only apply to HiFi equipment but also to e.g. microwave ovens and radar transmitters. They need about 5 minutes to get warm since the magnetron is a big solid lump of metal. The ideal solution for tubes would be to have a low voltage pre-heat applied to the filaments all the time that keeps them warm but not glowing. 

So what should one do? Leave equipment on or switch them off? Well, It comes down to for how long time it will not be in use, the amount of energy it consumes when idle vs in stand-by or off and if you want to wait for it to warm up...

I'm not a scotch drinker, but my tube system sounds better after a couple of beers. Seriously, I think both the amps and pre-amps are in their stride after a half hour's running from a cold start. Leaving the pre-amps on 24/7 is just a waste of electricity and more importantly, a waste of those priceless electrons. When I hit the feathers, everything's off.

Once turned on my tube amp takes 60 seconds before sound can be heard. That is for amp protection.  Just enough time to pour the Jamison. Sounds great from the start and better every sip. 

"allowing the processed signal from you cartridge (or other source) to complete transmission thru your speakers, where the signal is processed thru the tube grids opposed to the tubes in an idle state, speaker motors in a working state warming up and working the surround material, interconnects transferring signals, etc."

- say whut?

Great posts!  My Don Sachs preamp takes few minutes to sound its best and my McCormack DNA .05 Deluxe SS amp clearly takes a 30 minutes to sound optimally.  "Ear-lube" attributed to a beer or two might bias my impressions as "donjr"suggests above.  As a green-leaning guy, I can't bring myself to keeping my gear powered up 24/7.  

My system takes 30 to 45 Minutes to sound great! 

I do worry about the lights being on all of the time and burning out prematurely. My concern is always about the power surge. Turning it on and off is probably the most stressful challenge to the capacitors, tubes, bulbs, etc. Any thoughts about this?

Class D 'warm-up' depends on the loop design. Bruno's work is quicker - think 1/2hr to 1hr. IR based amps can take several hours. Others like ICE probably should be left on. 'Warm-up' is an asymptotic curve, so there's no absolute # - these are just guidelines. Longer the better.

All audio electronics have 'memory' issues thanks to physics of the materials. Caps, resistors, wire, all dielectrics, active devices - all that stuff. Even speakers (mechanical equivalents of previous). SO any warm-up or low-level maintenance for sonic quality should be driven with an 'AC' signal with load(s). Static 'warm-up' has value, but won't provide complete results.

Caps failing under continuous bias is a design issue. Electrolytics are a special case as they do have (xxxx)hr ratings. If your equipment does not have these things (look for cans with polarity indication), run as long as you can prior to use. Infinite is good.

Tube amplification w/o 'standby' are incomplete designs. Tube filaments benefit from not being flipped on/off all the time. Commercial tube equipment (like in radio/tv stations) were always left on - standby off while the stations were off air. Studios, same deal.

My Accuphase E600 sounds fine after 20 - 30 minutes. Sure, it gets better after awhile but that could also be attributed to a second cocktail. I used to sweat this stuff but not anymore. I just sit back, off center, and listen to all of my music. Don't sweat the small stuff. As long as it sounds great after it warms up you're in better shape than all the people that can't part with money for room treatments.

My Gato Amp-150 has a "warm-up" feature that brings the amp to optimum temps in 15 minutes.  My other amps take about an hour or so.

Well, maybe it's all in my head, instead of my ears, but it seems like my Kell FPB 400cx "comes in" after it's been on all day.  That's when I really think it sounds great.

It is simply drying out of electrolyte.  Every 10 degrees Celsius temperature increase cuts capacitor life by half.  Presence of voltage on capacitor is beneficial since it is rebuilding dielectric layer (aluminum oxide).  Without voltage electrolyte slowly eats up this layer.

Atmasphere,  thank you for your post. That is how I understood it also. Heat is the enemy really. 

Leaving your system on all the time can dry out the electrolytic capacitors (even on tube equipment).

This statement is incorrect. Usually filter caps have the longest life if kept charged. However, they don't like heat, insofar as long life is concerned.

My preamp 24 1/2 min amp is 31 1/2 min then they sound way cool.

I third you on the scotch and raise you on a fine French burdeux 

rvpiano, I second you on the Scotch - very effective.

The original NuForce is not in business, but there exists a technician who worked for them who is in business (called TDSS) repairing and upgrading NuForce equipment.

Starting with the sources...

VPI recommends turning on the table 30 minutes before use (VPI Aries)
AT-OC9/II phono cartridge usually takes one record side / 20 minutes to sound "right"
Herron VTPH-2 comes up the same time as the OC9/II -- 20-30 minutes
Transport takes zero time
DAC takes about an hour though I often just leave it on
Herron VTSP-3A about half an hour
Herron M-1 amps varies so I leave them on 24/7
Speakers need time depending on how long they have been idle.  Anything more than two weeks takes as much as an hour, maybe more.

My typical listening session starts an hour or more before I actually start listening.  I power up the entire system and start playing music through the DAC.  If I'm going to listen to vinyl, I play one record side while I listen to a CD through the DAC.  I do not leave the turntable playing a record unattended.

I’m running a Class D Taranis by Merrill Audio. Got a bit concerned by rvpiano’s tech’s comment about "on with no input signal" being bad for Class D. 

There is absolutely no reason why running without input signal would be bad for any class D amp.  This strange advice was given by NuForce technician?  Are they still in business?