Know you electrons....

[Clipped and Shorn]

a couple of naive questions:

1. How much more work (stress?) is there to electronic gear when the music is played than when the amps are idle (not necessarily with a standby mode). If you leave, say, tube gear, on for hours and hours, how much less is the gear working when music is not being played compared to when you are playing it. Is loudness a factor? Is this even a consideration.

2. What happens when electronic gear (tube mostly) really gets warmed up. Do circuits have a way of "seeking" some kind of equilibium when they have been on for hours and hours. I ask this because it seems that things get to sounding particularly good when you leave the amps on almost all the time. What is the state of a tube rig after hours and hours being on that is different than say the first half hour?

Do electronic circuits have a "will" to be their best, and eventually find a way towards this in spite of small anomolies that might exist (does the circuit, the big picture, over-ride, the "tolerances" of the parts...does this make any sense?), in other words, does leaving the thing ON, "polish the rock" so to speak, so it shines like the gem it always knew it could be........

Now I am afraid to turn this darn thing off......

C&S

[Cal Blacksmith]

Tubes do require a warm up time, after the first 1/2 hour or so there should be no noticeable changes.

Tubes do wear out just by being on. The manual that came with my Sonic Frontiers amp says to leave the amp on if you are going to stop for a few hours but if you are going to stop until the next day, shut it off.

Tubes do wear in together and reach their peak after about 200 hours of running from new. After that they hold level for a while then start a slow slide to used up. How long the tubes last depend on the amp design, ventalation, tube type and on/off cycles.

[Colin]

1.. Class A amplifiers are always on. In effect, they are always doing as much work.

2. Tubes, and even some solid-state equipment Ive heard, does warm-up and sound better after ½ to an hour.

Although I turn my equipment off and on during the week, if I know that I will have long listening sessions, I will leave it on all weekend.

[ben.]

I've heard it attributed to the transformer temperature, which makes sense. I think either Craig, Mark Deneen or JF Lessard posted something about it in the past year or so.

Good luck finding the post!

[DrWho]

Well heat certainly is a factor in electronics...moreso with solid state, but I can imagine it would affect tubes as well. I would assume manufacturers would be tweaking in their products after the temperature stabalizes that way it sounds its best for the majority of the time being used. I was at artto's place and it was the first time hearing tubes and I could tell when they just seemed to click in and start sounding better...so I really don't think it's a psychosomatic effect.

I have also noticed the same thing with all the tube guitar amps I've been working with...which is where I have more experience with tubes.

[WMcD]

One thing not mentioned but important is thermal cycling.

This is a reoccuring problem in electronics but is really a mechanical problem. Everytime you you turn a piece of electonics on and off, the metal used as conductors throughout expands and contracts. This leads to fatigue and eventual failure.

There are some other problems with electonics at start up. In the power supply there is a surge of current to charge up the capacitors. High currents are generally not good.

In tubes the high voltage gets applied before the filament gets hot and this is sometimes not good.

In the old days, tubes were used in telephone equipment and radio transmitters and were powered up for their entire lifetime. So they had a long lifetime.

As you can see from the above, that is why manufacturers generally counsel not to turn things off three times a day.

= = = =

A broader question is whether cranking up the volume will kill your equipment faster. Or, does keeping the volume down help prolong life. I don't think so. You don't see anything like that in literature from the golden age of vacuum tubes from the 1940s.

Of course that depends if you're running things into the danger zone on a regular basis. In most situtuations you're not. If you are, you need a bigger amp.

I really wonder about the various areas of discussion where speakers or amps are thrashed to near limits of their capability. People ask which design is better. What the heck, why are you doing that in the first place.

Best,

Gil

F

[Clipped and Shorn]

Well, I still have not turned off the Eico HF-81, it is now sounding so good all warmed up and hot, I cannot seem to get around to turning it off. Been listening mostly to CDs thru a classic Rega Planet and the Cornwalls. Sounding real good.

C&S

[Guy Landau]

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On 7/30/2005 12:15:56 PM Clipped and Shorn wrote:

Well, I still have not turned off the Eico HF-81, it is now sounding so good all warmed up and hot, I cannot seem to get around to turning it off. Been listening mostly to CDs thru a classic Rega Planet and the Cornwalls. Sounding real good.

C&S

----------------

How long has it been running?

[Clipped and Shorn]

most of the week.....

maybe will turn it off later this eve.....

c7s

[skonopa]

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On 7/30/2005 4:24:35 AM William F. Gil McDermott wrote:

There are some other problems with electonics at start up. In the power supply there is a surge of current to charge up the capacitors. High currents are generally not good.

In tubes the high voltage gets applied before the filament gets hot and this is sometimes not good.

----------------

That makes sense. After all, when is it that a lightbulb typically goes Kaput? When you first turn it on!

This is a pretty common debate in the computer circles with regard to typical desktop workstations (not servers, since they are typically left on anyway). Is it better to leave the machine on or to turn it off. One side says it is bettr to leave it on, since for the same reasons that Gil stated above. Others think it is just a waste of energy to leave a machine on that is not being used. There is also some concerns with safety, i.e., something overheats and catches fire, as well as (in the case of computers), a left-on machine, especially if connected to the internet, is a target for black-hat hackers. After all, the best way to keep hackers out of a computer is to turn the thing off. Personally, I am of the school that you should need to only turn a machine on once a day, in the morning when you are about to use it, and turn it off in the evening when finished. At least that is what I do for the Windows PC I have at work. My unix workstation stays on all the time, but it goes into a "standby" mode when not in use.

As for amps, the only amp I have that is really worth mentioning is my solid-state B&K amp. I pretty much leave that thing on all the time. It has been like that (save power failures or if I am going to be away for an extended period of time) for the past year and half, and it does not seem to effect anything.

[Guy Landau]

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On 7/30/2005 1:42:24 PM Clipped and Shorn wrote:

most of the week.....

maybe will turn it off later this eve.....

c7s

----------------

I don't think that it's such a good idea to leave it on that long. There's no real reason not to turn it off during the night.

My HF-81 sounded great within an hour. Has it been rebuilt?

[Clipped and Shorn]

Craig straightened it out a couple of years ago.

Why do you say it is not good to leave on for that length of time?

c7s

[Marvel]

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On 7/30/2005 2:06:43 PM skonopa wrote:

That makes sense. After all, when is it that a lightbulb typically goes Kaput? When you first turn it on!

----------------

A light bulb is a lttle bit different. The filament (tungsten) has almost zero resistance when cold, so it allows a very large current flow. The resistance goes up as it heats up so the current flow drops. It does, however, heat up very fast.

This is the idea behind using a light bulb in a tweeter protection circuit.

[popbumper]

Physics would suggest that anything electromechanical left to sit idle will not perform at its peak when first "activated". Molecules/electrons do not move well until forces are imposed on them, and then they tend to "avalanche" - it takes less effort to sustain the momentum than to first start the action that causes the momentum.

The human body follows this principle - imagine getting out of bed, donning shorts and immediately running a race without stretching or warming up in any way. An automobile, when first started will not produce peak horsepower readily if pushed hard before everything reaches equilibrium. Simple laboratory chemical reactions tend to be more "volatile" if the components are thouroughly mixed and/or heated, and are at least at room temperature. A pizza oven which is well heated and stable in temperature will cook a pizza far more evenly than the first pie of the day.

Hope that helps - electronic systems are nothing more than physical models which require equlibrium to perform at their best.

Chris

[mike stehr]

I have a couple Bendix 5852's, a heavy duty version of a 6X5 I suppose.

I tried it my tube tester as a 6X5 the other night.

I just looked at the data for the Bendix 5852, it has a 45 second heater cathode time.

I was wondering why they took so damn long to come up.....

[Clipped and Shorn]

ok, I just shut it down, but it was nice having it always on the ready to play music for an hour or so whenever I would come back into the house from working outside. Now I will have to go back to the utility SS system which I tend to not fuss with, turning on and off whenever I feel like it. I was enjoying the Eico/Cornwall system this week and would put on a CD at bedtime and fall asleep, that is why the system stayed on, because in the morning rather than turn it off, I just immediately started playing music again. You can see the temptation to just leave the system on all the time, especially because of the all the tubes. Like was stated in this thread, there are actually quite a few hours in those tubes. I kind of like this idea of playing that system for maybe a week at a time. My tri-amp system is another matter and I do not feel comfortable leaving that system on indefinitely, but the Eico HF-81 system....well, it is just an HF-81....and when it blows....who knows .... the pCats might be rolling down the assembly line.....

replace the system with Merlin+pCat....hmmmmm nice dream....

C&S

[dragonfyr]

"Physics would suggest that anything electromechanical left to sit idle will not perform at its peak when first "activated". Molecules/electrons do not move well until forces are imposed on them, and then they tend to "avalanche" - it takes less effort to sustain the momentum than to first start the action that causes the momentum."

-------------------------

I don't mean to drop the fly in the soup, but this analysis of electron flow based upon extrapolated classical models of mechanics is, well, wrong. Electron flow does not operate, nor is it predicatable by classical models, rather it falls into the realm of quantum mechanics, where energy is quantized.

And I quote the above, NOT to single it out, but simply to use it as it attempts to focus on the subject in a much more direct manner (much to its credit!!) then many of the other posts!

Without giving a lecture, let me give you a very simplistic example of what this means.

In your classical model, work is performed by applying force equal to, or greater than, a certain minimum critical amount of energy. To boil water you apply at least enough energy to raise water to 212F/100C (STP), or to move an object , you apply enough force to overcome static friction. And if you apply an even greater force, well, that just means you accomplish more 'work'.

BUT NOT IN QUANTUM!!!!

In quantum energy is quantized. And the amount of force required to perform work is quantized - meaning that the required energy is very specific - exact! Thus, if we apply this to our classical examples above, it would require that an amount of energy equal to exactly 212F/100C(STP) be applied to make water boil. 211.9999999999999F won't do it! Nor will 212.000000001F, nor will 212^10^999999999F do it! You can apply an infinite amount of energy and the water will just sit there staring at you. But it wont boil.

Thus, in quantum, the amount of energy required to free an electron from its valence is quantized. And only a specific 'exact' amount of energy will ionize (free) it. There is no applying 'enough' and thus simply 'getting it going' - and no, we are not speaking of fission!.

If anyone wants to discuss this ad nauseum, please let me know, as my research for the Dept. of Energy and Navy while teaching was specifically the development of a "frequency agile SS infrared laser for use in resonance ionization spectroscopy" for use in some 'other stuff'. So I can try to explain it on the 'electrons are your friends and they travel down the wire holding hands' level, or with as much math as you (don't!) want. So much for what I was doing during the day when I wasn't doing the acoustic analysis 'stuff' and sound at night. Actually the time element was rather flexible, so they might have been reversed on more then one occassion! ...Right up to being brought down here to work on the massively parallel computing stuff (RS6000SP).

For what its worth, I designed a frequency agile laser that was able to provide a tunable swept function output (lasers have traditionally been mode locked to be stabile at only one precise frequency), which when directed onto a substance would, as the laser's frequency was changed, free electrons at precise frequencies. Each frequency corresponded to a unique energy level. And as EACH element's electrons have a unique energy signature required to ionize them from their from their particular position in each valence, as an electron was ionized and measured by a photomultiplier, you could determine the composition of a substance down to one one atom of 'stuff', depending upon the exact frequency (with its exact corresponding energy) that caused the ionization of the electron. Matching the energy to the particular electron potential identified the element. ...Thus making it the most prceise form of spectroscopy yet available.

But I am sure none of you care about that, but the point is that electron flow, while often described in terms of classical images for convenience does NOT actually behave this way! And trying to do so will not add to an increased understanding! The best you can do is to address the thermal stability and equilibrium of materials. But beyond this, you again enter the quantum realm as soon as you approach the realm of near massless 'things' going near the speed of light- electrons, etc! And all of the classical models of pool balls bouncing around, or of waves, or of any other model, begin to break down and become invalid. So the significance of this rambling is that the simple models often employed to explain simpler behavior, are not valid for explaining the behavior of electrons within materials. So let's just try be aware of these limitations.

Here is a nice succint description of some of the limitations of using classical models to describe quantum behavior - but remember, it deals with quantum ONLY on the very surface!

http://www.madsci.org/posts/archives/aug2001/999006368.Ph.r.html

[popbumper]

Thank you for helping me to recognize my limitations. It would have been much better had you just responded to the thread in the first place, and I could have ignored your response sooner and never said anything. Talk about "ad nauseum"

You lost me after the first couple of sentences, and probably everyone else for that matter. Not that there's anything wrong with that, you obviously have a profuse education and capability.

Chris

[dragonfyr]

The point is, except for modelling the thermal behavior of materials, electron flow is not able to be accurately modeled using the classical model beyond some very elementary characterisitics.

[skonopa]

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On 7/30/2005 6:15:36 PM popbumper wrote:

You lost me after the first couple of sentences, and probably everyone else for that matter. Not that there's anything wrong with that, you obviously have a profuse education and capability.

Chris

----------------

Sad thing is that I actually understood what he was talking about.

Back to an earlier post, I mentioned the lightbulb since that is the most common example where I've seen something fail upon powering up. I've encountered computers that were running fine until powered down. The next morning, tried to turn it on and the power supply went "poof"!. Same thing happened with a TV set many years ago.

The point I was trying to make that, at least from personal experience, most failures occur upon initial powering up, since that initial surge of power when turned on is what usually does something in that was on the verge of failing anyway.

After all that, the general concensous is, especially with tube-based analog equipement, to turn it off in the evening before going to bed.