How do you "burn-in" your builds?

[Gaz]

I've never done this myself, but I always hear stuff like: 'Burned-in under full load for 24 hours." WTF is "full load?" Do they mean actually mean with full current draw, or just at max clean power?

I think running a 100W Plexi at full power for 24 hours would just eat the tubes. Most guitar amps are running beyond max spec of yesterday's tubes, and I would thin "burning-in" for so long under extreme conditions like that would be unwise.

I'm also not talking about burning-in for "tone," but rather to test an amp's reliability before gigging. One other concern of course is: Is this safe? Let a new amp run all day and night unsupervised? I would think this would be unwise for even the pros with a small warehouse full of their liveihood. Fire hazard anyone?

So with all that said, I would love to hear everyone's thoughts on this subject, and your personal method of "burning-in" new amps.

Thanks!

[Structo]

Well I think that may be a bit geeky for most guitarists.
Seriously, plug in, play, turn knobs, turn the volume up loud, down soft.
If you are going to put hours on an amp, you might as well be playing.
Tubes have a finite lifespan.

Maybe commercial builders do that to test the amp to make sure nothing
goes bad after so many hours.

I don't like leaving amps on when not at home.
It's like six or more really hot light bulbs all crowded together.
In a wooden case.

I know we have a lot of other appliances that are on all the time.
But as we know, vacuum tubes/ components can fail suddenly without
warning so, eliminate one hazard, turn the amp off.

Uh, anyway that's my 2¢

[Gaz]

Well I think that may be a bit geeky for most guitarists.

This is the technical section of an amp building forum, right?

Seriously, plug in, play, turn knobs, turn the volume up loud, down soft.
If you are going to put hours on an amp, you might as well be playing.
Tubes have a finite lifespan.

I totally agree, but what if you have to ship an amp to a customer, or in my case give one to a guy who is gonna record with it for 5 days straight. I don't want this thing to die in the studio because I didn't test it well enough. I can't play it at home for hours on end, so just wanted to get an idea of what other people do to burn-in amps if anything.

Maybe commercial builders do that to test the amp to make sure nothing
goes bad after so many hours.

They do, I've heard it mentioned many times. It's just super vague.

I don't like leaving amps on when not at home.
It's like six or more really hot light bulbs all crowded together.
In a wooden case.

I know we have a lot of other appliances that are on all the time.
But as we know, vacuum tubes/ components can fail suddenly without
warning so, eliminate one hazard, turn the amp off.

I agree, and I'm not paranoid about heat build, but rather the fact that the whole purpose of the hypothetical burn-in is that nothing goes wrong, or potentially catastrophically wrong. If it does, I think someone should be there when it happens. That's why I'm wondering if amp manufacturers really leave racks of amps running all night.

Thanks for the thoughts.

[martin manning]

I gather that many boutique builders will do a burn-in for a few hours. I think it's a good idea, to let things settle in so you can confirm that the voltages and bias are stable, and so you can make a final adjustment. I believe that there will be some tonal changes in the first couple of hours, so it's good to confirm that the amp is sounding as it should when you make that final bias setting. Some people believe it's important to run signal through it during the burn-in period, and will use a music player and a dummy load for that.

[Littlewyan]

I would play through the amp for a good few hours if it was me. Check the bias after about 30minutes of playing and it will probably drift a bit at first. Maybe keep turning it off between breaks as well to make sure it switches on ok every time.

I am a bit wary myself of leaving amps on all day by themselves. If I did leave it on all day I would definitely run a signal through it, some music would be best as you're pushing a wide range of frequencies through it rather than just a 1Khz Signal or something.

[ToneMerc]

I've never done this myself, but I always hear stuff like: 'Burned-in under full load for 24 hours." WTF is "full load?" Do they mean actually mean with full current draw, or just at max clean power?

I think running a 100W Plexi at full power for 24 hours would just eat the tubes. Most guitar amps are running beyond max spec of yesterday's tubes, and I would thin "burning-in" for so long under extreme conditions like that would be unwise.

I'm also not talking about burning-in for "tone," but rather to test an amp's reliability before gigging. One other concern of course is: Is this safe? Let a new amp run all day and night unsupervised? I would think this would be unwise for even the pros with a small warehouse full of their liveihood. Fire hazard anyone?

So with all that said, I would love to hear everyone's thoughts on this subject, and your personal method of "burning-in" new amps.

Thanks!

I will usually let them burn in at idle for 2-4 hours and then pump a signal through it for an hour.

I look at this way; if I really have to worry about my builds being a fire hazard, I most likely should not be building amps.

TM

[labb]

I play a CD player through mine for an hour. Turn it off for a while then play the CD player through it again. I do this 4 or five times. Never thought of it as burning in the amp. Just the way I check one.

[guitarmike2107]

I remember seeing a online factory tour of badcat or Matchless where they had shelves of amps "burning in"

Here is Carr, skip to 5:50 or so, amps just turned on and burned in for 24 hours

here is one from 65 AMPS

https://www.youtube.com/watch?v=uqiijqR95do

here is krank, jump to 2:00 - 40 hours

https://www.youtube.com/watch?v=G6GMLWHOp0Y

I don't see any big dummy loads

[Andy Le Blanc]

run pink thru it for 15 min.... play the crap out of it ... thump it hard a few times

repeat

nothing like the back of a pickup truck up a dirt road and a smoking jam

[Gaz]

Thanks. Everyone's suggestions/experiences all sounds reasonable to me too, and I think a couple hours with full range music or pink noise should do the trick.

I also agree that if you think your amps are possible fire hazard, maybe you should rethink your construction techniques But you know, shit happens out of your control (faulty parts), and it's best have something smoke on your bench than in the control room of a studio.

And thanks a lot to guitarmike2107 for all the links, I had seen most of those at one point, which eventually led me to posting the question!

[roberto]

Well, it depends on what you mean by burn-in.

It you mean the one you do to stabilize bias and voltages and so on, just switch it on and let it run for few hours.

If you mean the burn-in process for sound evolution, I do nothing.
Just playing.

[Reeltarded]

I look at this way; if I really have to worry about my builds being a fire hazard, I most likely should not be building amps.

TM

This is why I don't have children.

[Gaz]

Well, it depends on what you mean by burn-in.

It you mean the one you do to stabilize bias and voltages and so on, just switch it on and let it run for few hours.

If you mean the burn-in process for sound evolution, I do nothing.
Just playing.

Yes, that's what I mean. I mentioned I did not mean for tone. I don't believe in that crap That's for the Sozo suckerz

[boots]

I burn in my builds for several days with a function generator and a dummy load. When I'm at home, I crank it. When I'm away, I'll usually turn it down to a pretty low to medium output. I use an old set of tubes so I don't unnecessarily wear out sweet tubes.

I don't believe that it takes 100 hours to make tone caps sound good, but I figure a good burn-in is good in many ways.

Fire hazard is definitely worth keeping in mind. I set the amp, out of cabinet, in the middle of my bench and make sure the dummy load has good air circulation. I don't leave it cranked while I'm away from home.

[TUBEDUDE]

I just play the crap out of it for an hour or three a day for 2 weeks, then check bias and plate voltages. Then tell the customer although it sounds great, it will get even better as the components settle in, especially thespeaker.