Leaving amplifier on and effect on speakers

[fred40]

Hi All,

I leave my amplifier always on (as recomended by the manufacturer) I wonder if this has any negative effect on my Harbeth speakers ( P3 esr) as recently suggested in an other audio forum.

Grtz Fred

{Moderator's comment: are you serious? What is being said?}

[STHLS5]

My personal experience - after reading from one of the forums I left my 1500 watter (with four 30000 uF capacitors )Amp ON for about three or four months. The electricity bill went up almost double but the sound was the same as leaving the Amp on for about 20 minutes.

Newer amps need much shorter time to stabilize and perform optimally unless it is some power guzzling amp like mine. OTOH, if your amp comes with standby mode then I would suggest you leave them in the standby mode when not in use otherwise turn them OFF when not in use.

There is always the danger of your drivers coil getting heated up if you leave the Amp ON all the time unless it is in the standby mode.


ST

{Moderator's current: if there is no music playing, there is really no current flowing. So the voice coils should not heat up.}

[garmtz]

Like to moderator says: no sound = no damage! Unless there is some SERIOUS DC on the output of the amp, the speaker will not wear at all from only the miniscule amount of noise (in the mV range at most) generated by the amplifier.

[fred40]

Gentlemen,

No there is no standby switch on this gear neither on the amplifier, or the cd player. It"s either on or off, there is no alternative.

In the forum I spoke about it's said that it is best to shut the amplifier down with the remark and I quote " The boxes will love you for it" Without any further explanation why

Greets Fred

{Moderator's comment: then 'the boxes will love you for it' must be true if its on another forum - right? They WILL love you for it when the amp goes DC ..... but for no other sonic reason.}

[garmtz]

In this case, I guess they meant 'doosjes' instead of 'boxen'. In other words, the electronic equipment (=NAIM components) will love you for it.

I do not agree with this however, as your Naim equipment is supposed to stay on, that is how the manufacturer recommends it. Turn it completely off when you are away for a longer period, say more than a few days. If you value the environment above all else, by all means have the equipment turned off as much as possible... :)

[garmtz]

I have found the topic in question:

http://forums.naimaudio.com/displayF...04822880147737

What is meant is really this: switching of Naim equipment once in a while (so for example one night every month) will do good for the sound quality of the components (no explanation is given). It has NOTHING to do whatsoever with the speakers. In English, 'boxes' doesn't mean 'boxen'! :) So the sentence means: Your Naim equipment will love you for it.

{Moderator's comment: Get away. Is anyone sufficiently gullible to actually believe that twaddle? It is so obviously a tongue in cheek joke dreamed up over a few beers.}

[kittykat]

They will love you for it when components fail and it has to be replaced.

Miller Audio measures amplifier distortion over time and leaving it on does not make a significant difference. If there are it indicates incompetent design.

How would people feel if Sony tells us we have to leave our TV's on so the colours will be richer. Absolutely ludicrous.

[A.S.]

They will love you for it when components fail and it has to be replaced.

Miller Audio measures amplifier distortion over time and leaving it on does not make a significant difference. If there are it indicates incompetent design.

How would people feel if Sony tells us we have to leave our TV's on so the colours will be richer. Absolutely ludicrous.

Absolutely. Another heap of utter BS that has grown legs and meanders freely through audio forums concerns the 'improvement' in the sound of solid state electronics after a period of x hours to 'burn-in'. It is pure and utter fantasy. There is no electronic component in solid state electronic systems that can be 'improved' with age. The opposite is true. The electrons in your amplifier formed during the Big Bang, behaved the same then as now. And will continue to do so into the far future.

The sonic performance of the amp will be the same the instant it is switched-on in the factory for primary QC test, one hour, one day, one week, one month, one year or hopefully ten years after it was made whether or not it is occasionally powered-on for use. The only components that are vulnerable to age are those fabricated from a moist chemical brew such as the power supply electrolytic reservoir capacitors, and these do have a working life clearly specified by the manufacturers. That working life is related to many factors including but not limited to -

• Operating ambient temperature as this will cook the capacitor's chemistry
• Current being drawn (how 'hard' the capacitor is working)
• Chemical stability of the internal mixture
• Quality of the sealing of the can to hold-in the chemicals and minimise evaporation
• Basic electro-chemical design; is the item genuine and the product of proper design/QC or a forgery*
• Voltage across the capacitor
• Physical size
• Colour of the case (ok, kidding: totally irrelevant)

Now, the fact is that the working life of the capacitor is related to its powered life. Sitting on the shelf in the cool store room, unpowered, unworked, assuming that the case sealing is good, the useful shelf life will far exceed it's operational, powered life. This implies that to extend the life of your solid state electronics it should be completely turned-off when not in use. Not standby mode (where the PSU is obviously still charged up and working) but fully off.

Look here at a good quality typical PSU capacitor of the type that would be found in an audio power amplifier (at least two needed): Panasonic 10,000u 63v can type. About half way down the page you'll see Lifetime .... 2000 hours. or this one, lifetime 3000 hours. I haven't read the small print about the definition of 'lifetime', but whatever it is, there are 8760 hours in a year (24 x 365), so a 'lifetime' of 2000 hours equates to a fraction of a year, if worked continuously. These 'wet' components are the only ones that can degrade in a solid-state system, and they certainly cannot ever improve with age - never. Like cooking a steak, as an electrolytic capacitor gently cooks under load the moistness progressively evaporates as it passes from rare to well done over 2000 hours or so.

Like so much of the regurgitated twaddle that one encounters in many walks of life, the truth is often the opposite of the urban myth. It is extremely frustrating that the voice of objective, rationalism (aka engineering) is buried under layer upon layer of misinformed chit-chat. How man ever amassed enough pragmatism to build churches that have stood for 1000 years considering the almost total lack of objectivity and reasonable scepticism nowadays is truly a miracle.

We've looked at (typically blue cased) electrolytic capacitors which are the cheapest and least durable type of high-value capacitors yet are widely used in loudspeaker crossovers for very low cost/small size reasons - here

Another factor to consider is fire. Any powered equipment is a fire hazard with a continuous supply of fuel.

*If you want something to really worry about, be aware that there is an increasing number of fake PSU capacitors in circulation. The situation is now so endemic that European audio electronic makers have had to import amps OEM manufactured in China, one by one open them in Europe, disassemble the PSU circuit, unsolder and replace the PSU capacitors with genuine originals and reassemble and test. Imagine having to repeat that 1000 times. And the unexpected cost at tens of thousands of pounds just to minimise a flood of Warranty claims a week or two into the amp's life when the short life expectancy of the fake components is reached. And hopefully before they self-ignite.

[STHLS5]

Speaking from my personal experience, my previous subwoofers amp developed a slight hum after leaving it off for about a year. The CD players lens died and one of the remote control for my DVD player stopped working. Most electronics equipments malfunction if not in use for a very long time.

Ideally, electronics should perform at the best at normal room temperature. However, in reality large capacitors and power supply produce heat which in turn affects the voltage across the circuit board. As heat increases the resistance of the cooper rises too which will affect the current.

The immediate measurable difference can be seen is when you measure the quiescent bias current which will increase with the rise of the temperature. Usually after 10 or 15 minutes the amplifiers temperature rise will stabilize and that's when you measure your bias current and set according to the manufacturer's specs.

The bottom line is temperature does affect electricity conductivity. So the best way to have a consistent performance is when the actual working temperature stabilizes. This is not much a problem with little heat dissipating amplifier.

Can you hear the difference of 10% difference in the quiescent bias current before and after the warm up is another question but to say amplifiers performance is exactly the same irrespective of the internal temperature is not quite correct, IMO.


ST

[Pluto]

The immediate measurable difference can be seen is when you measure the quiescent bias current which will increase with the rise of the temperature. Usually after 10 or 15 minutes the amplifiers temperature rise will stabilize and that's when you measure your bias current and set according to the manufacturer's specs.

A solid state amplifier which is not entirely stable within a minute or two of switch-on is either faulty or a poor design.

[keithwwk]

Same amp design sound too unnatural that you need to adjust your ear or better word "believe" it is the correct sound. By asking user to keep the amp on 24/7 for ensure fully warm-up and optimal operation condition is a trick to user to think "My amp is in best sounding" because it is turned on 24/7!

I have a friend keep is amp (So called class A 750w) in standby mood 24/7 and in cost of additional 100 bill. Before he switched it in standby mood was in "On" mood 24/7 and cost additional 200 bill.

In fact, it is your mood that affect the sound you heard but nothing is related to the 24/7 switch on time. When I need music, I can enjoying by turn on my amp from cold and enjoying the music from the 1st second. It is like listen music at night. plenty of them said that sound getting nicer and nicer is because everybody is sleepping and the electrical power is stronger, steadier, cleaner without aware that is due to quieter background and your relaxed mood which let you carry-on...

[fred40]

Gentleman,

So if Naim recommends to leave the amplifier on 24/7 (for what ever reason) the conclusion is that Naim makes amplifiers with a faulty or a poor design. Find that hard to believe to be honest.

Grtz

Fred

{Moderator's comment: OK, you choose what you want to believe.}

[fred40]

Moderator,

A It"s just that I don"t believe that!

[A.S.]

Gentleman,

So if Naim recommends to leave the amplifier on 24/7 (for what ever reason) the conclusion is that Naim makes amplifiers with a faulty or a poor design. Find that hard to believe to be honest. Grtz

With due respect that's not a satisfactory conclusion to draw. First, we all know that Naim have a reputation for making highly respected products. We also hear that there are certain charming quirks of Naim products/marketing/personnel which make them stand-out in a market awash with competitive products.

Talking generally about brand marketing and not about any one product or brand, commercially successful brands have a nurtured personality, a certain style, and the way they lead opinion is all part of the mystique. Steve Jobbs at Apple, Sir Richard Branson at Virgin, Lord Sugar at Amstrad, Enrico Ferrari, Rupert Murdoch at NewsCorp. and so on. What we are discussing here is separating the marketing speak from the technical reality since they must both co-exist in any modern, successful brand. Every statement, every utterance, every point of contact with the trade and the public that starts out as a pure engineering issues is inevitably filtered trough the marketing/PR department and given the appropriate spin to meet commercial imperatives. I don't need to spell that out - surely it's blindingly obvious that how successful business works.

The issue here is to decode every bold statement emanating from the marketing department relating to a manufactured product and ask yourself what is the proportion of 'spin' to engineering fact? 70% some sort of engineering reality 30% marketing talk? 70% marketing talk (just to create a product differentiation - essential for sales) and 30% engineering? That you have to decide based on common sense, and an awareness of the engineering issues (or non-issues). But this presumes a certain basic, at least high school understanding of what is going on under the hood. If you do not have the luxury of that fundamental knowledge of electro-magnetism, then you may be able to fall back on your later life skills as a business, communicator or marketing person to sniff-out a good marketing tale when you see it. If you don't have either the high school knowledge or the marketeers insight then you can fall back on natural suspicion and your starting gambit should always be 'I'm going to assume that's someone's marketing spin until I investigate further amongst people who actually know about the subject...'. We've laid this issue out in black and white here.

Returning to the specifics of this thread - Pluto accurately stated ...

A solid state amplifier which is not entirely stable within a minute or two of switch-on is either faulty or a poor design.

He is absolutely correct about this. For a man-made system (electrical, chemical, mechanical) to be stable such that it can and will respond appropriately to an input stimuli with the correct output stimuli, there must be only a short time for it to reach operational temperature (a real, measurable, predictable fact) and then it must hold steady in that stable condition forever, or until one part of it fails. If there are any time lags in system such that perfect operational functionality is only possible after a prolonged lag from start-up then, as Pluto says, it fails the first hurdle of being a stable system. If, when you turn the steering wheel of your car there iss a 20 minute lag before the road wheels responded, the car would be by definition, so unstable and unresponsive as a mechanical system that it would be useless.

The same with amplifiers: as they have to trace every microtonal nuance in fast moving music, there cannot be a time lag inside; it must be stable within seconds of power-on or it cannot be defined as a high-fidelity system. Just like a wrist watch, stability and absence of drift are pre-requisites for the basic function; the same is true of audio equipment.

[STHLS5]

Same amp design sound too unnatural that you need to adjust your ear or better word "believe" it is the correct sound. By asking user to keep the amp on 24/7 for ensure fully warm-up and optimal operation condition is a trick to user to think "My amp is in best sounding" because it is turned on 24/7! ........

Electronics equipment lasts longer with less turning off and and restart because it adds stress to them. A standard Philips bulb suppose to last 36000 hours but the manufacturer clearly states that frequent "ON" and "OFF" shortened the life span. I cannot find the specs for the good old filament type bulb but clearly remember the same caveat applied to them as well. Common sense tells us that heat cause things to expand. So if you keep on changing the internal temperature of an Amplifier by about 20 Celsius frequently by turning them on and off you are creating stress to the various parts in the amplifier. It could be the solder joints or the transistors emitters and things like that.

A solid state amplifier which is not entirely stable within a minute or two of switch-on is either faulty or a poor design.

At least you concede that it requires a little bit warming up, thanks. So there must be something happening within the one or two minutes warm up time.

Gentleman,

So if Naim recommends to leave the amplifier on 24/7 (for what ever reason) the conclusion is that Naim makes amplifiers with a faulty or a poor design. Find that hard to believe to be honest.........

Honestly, a perfect amplifier should function the same irrespective the warm up time. You dont expect a Fluke Multimeter to warm up first before taking a measurement right? However, the reality is heat causes changes and amplifiers do heat up considerably.

Naim is not alone in recommending warm-up time or in this leaving them on 24/7. As far as I know Krell, Bryston, Classe, Arcam, Parasound and Denon do recommend a minimum warm-up time. They all being honest in their own context. Surely, you cannot expect them to say that their design is still far from perfect. Perhaps you can direct the question to Naim asking them what changes takes place by leaving their Amp 24/7.

And if you are still so curious about heat and its effects, the next time when you listen to music do you notice yourself gradually increasing the volume about 3 or so dB after 1/2 hour of music? Is it because you ears becoming dull or the speakers loudness gets reduced after sometime?

ST

[Pluto]

May I suggest you read "The Audio Power Amplifier Design Handbook" by Doug Self (ISBN 978-0240521626). This author* offers one of the most open discussions of amplifier design techniques you could wish for.

Self says, "It is often stated in hi-fi magazines that semiconductor amplifiers sound better after hours or days of warm-up. If this is true (which it certainly is not in most cases) it represents truly spectacular design incompetence."

{Moderator's comment: *a world authority on amplifier design}

[A.S.]

...And if you are still so curious about heat and its effects, the next time when you listen to music do you notice yourself gradually increasing the volume about 3 or so dB after 1/2 hour of music? Is it because you ears becoming dull or the speakers loudness gets reduced after sometime? ST

What is the answer to that question?

[GregD]

What is the answer to that question?

This was about STHLS5's question about why might you turn the volume up after about 30 minutes of listening. I think he was implying that this is because the amplifier is settling down during this warm up period. I have to strongly disagree.

It is a very well-known scientific fact that if humans are around loud continuous sounds like music, that our hearing system starts to close down to protect itself gradually. This changes our perceived frequency balance perception too. So if you play loud music with copious bass output, after a short while your hearing will start to close-down progressively and you will think the music seems quieter and the bass lighter. So what do you do? Turn the volume up to compensate! That's your answer, no HiFi mumbo jumbo to investigate here.

I'm told this is a problem for sound engineers, where the speaker might have to be played loud in order to hear the correct tonal balance. The problem is that after a few hours of this high volume listening the engineer's ears are very fatigued so he can't do the job properly any more. Using Harbeths in the studio avoids this as they sound perfectly balanced at a safe long term 85dB level - just ask Pluto.

I've known people who have their TV volume set so high because they started with it high in the first place and then purely because of the initial high volume, they had to keep turning it up in order for it to still seem loud enough 'to them'. But when anyone else who's just been sitting quietly elsewhere walks in, they find it a crazy deafening racket! Same reason.

There are many examples of this type of thing. People who add lots of salt to food and lots of sugar to tea. They get used to a certain level and become somewhat desensitised. Tests have shown that if the levels are gradually reduced the subjects don't realise. People ended up with no sugar in their tea and didn't know the difference.

So, start playing music at a lower volume and/or have regular breaks to avoid what is essentially damaging your hearing. If I've been in town all day in the busy street I never put the stereo on straight away because my hearing is still affected by the loud continuous din of the busy street. It's better to have total quiet for a good hour before you try any proper listening, that way the music sounds better and you don't have to play it so loud to hear all the detail you know is there.

[keithwwk]

Electronics equipment lasts longer with less turning off and and restart because it adds stress to them. A standard Philips bulb suppose to last 36000 hours but the manufacturer clearly states that frequent "ON" and "OFF" shortened the life span. I cannot find the specs for the good old filament type bulb but clearly remember the same caveat applied to them as well. Common sense tells us that heat cause things to expand. So if you keep on changing the internal temperature of an Amplifier by about 20 Celsius frequently by turning them on and off you are creating stress to the various parts in the amplifier. It could be the solder joints or the transistors emitters and things like that.

And if you are still so curious about heat and its effects, the next time when you listen to music do you notice yourself gradually increasing the volume about 3 or so dB after 1/2 hour of music? Is it because you ears becoming dull or the speakers loudness gets reduced after sometime?

ST

The bulb can not apply to this because the frequency of on/off of the bulb is seriously much, very much higher than what you will do on amp. No one will turn off the amp's power switch and on it again when changing a track or CD, unless you are ABing power cord, Think abt this you can understand the logic.

As for the heat issue, in general usage and within the operation range, the heat will not be an issue at all because the basic design for electrical and electronic are undergone some extreme condition like long hour baking/frozening, various of temp in 1x, 2x, 3x, 4x reflow in specified hrs etc before finalised. The heat issue you mentioned is almost zero if you operate the amp in a common way. Only some class A amp heat can really give problem especially 24/7 turn on time is like baking the whole units in infinity time!

I am not sure what is your heat to vol and hearing relation. Based on my personal experience and at least what I am doing so this few yrs with an amp without remote, the reason I increasing the vol is to compensate the loudness if the album I going to play is pre-recorded in lower level (compared to the just finished album). Order than that, my listening vol is almost steady and constant thru out the whole album.

The only reason for me to think of why need gradually increasing the volume about 3 or so dB after 1/2 hour of music is either the listening mood is growing than ask for slightly more kick or (if still gradually/repeatedy increasing the volume about 3 or so dB after 1/2 hour of music) the person must be having some hearing issue (Either suffered from hearing damage by too loud hifi or having a bad day with running nose with ear blockage). This, in the end lead to listening fatigue.

[jair44]

....At least you concede that it requires a little bit warming up, thanks. So there must be something happening within the one or two minutes warm up time.

I kept on my Naim 42.5/110 powered on for over 10 years with no problems, and it was about 10 years old when I got it ! So I kept up this practice with my Magnum IA170, and again no probs. I also gave away a 1970's Japanese amp which is also left on, and that's still working.

Yet rather disturbingly my sister's NAD c315BEE failed due to 2 leaking caps after 16 months of use despite being powered down after every session. Similarly my current Creek Destiny amp had to be sent back for repair for leaking caps within the guarantee period despite being powered down after use. I should mention that the response from the manufacturers in both cases was brilliant and the issues got sorted.

So now I leave my gear in standby believing this is a good compromise between energy use and reliability. It does seem as if it is the capacitors that are the weak link in ss amplifiers and that they don't like being continually powered on and off. Of course valves are a different matter.