Burning smell coming from amp occasionally

Waffles and Scotch · #1 08-16-2011, 09:41 AM

I have a Mesa M6 Carbine (600W) rack-mount amp that was installed in a Gator case (got a discount for buying a floor model and the case was free). I've noticed when the A/C doesn't work at our practice spot it gets really hot. A couple of times we've smelled something burning, and it's coming from my amp. I'm guessing it's the amp melting the plastic case a little, and was wondering what kind of damage (if any) this would cause to my amp. So far I've had zero issues, but as you can imagine the smell of something burning/melting is making me nervous...

anonymous02282011 · #2 08-16-2011, 09:46 AM

Quote:

Originally Posted by TF Ghost

I'm guessing it's the amp melting the plastic case a little, and was wondering what kind of damage (if any) this would cause to my amp.

Fire damage.

and it has nothing to do with the A/C in your practice room. I wouldn't use the amp again until the problem is resolved.

Waffles and Scotch · #3 08-16-2011, 09:53 AM

Quote:

Originally Posted by adbass

it has nothing to do with the A/C in your practice room.

So far it's only happened twice, and both times it was over 100 degrees in our practice spot. Each time it happened we smelled it within 30-45 minutes of playing, and we've played for 2+hrs many times without issue...

BurningSkies · #4 08-16-2011, 09:55 AM

Is your amp coal or wood fired? If so, that smell is normal... Otherwise take it to the amp doctor.

Rockin Mike · #5 08-16-2011, 09:56 AM

Do you have a backup amp for the day the Mesa falls down?
Might want to have that fixed, especially if the warranty is still in effect.

Cb4rabid · #6 08-16-2011, 10:32 AM

When I bought my Gator case, it also had a burnt kind of smell to it. It's fine, I guess it's just the way these cases smell.

anonymous02282011 · #7 08-16-2011, 11:02 AM

Quote:

Originally Posted by Cb4rabid

When I bought my Gator case, it also had a burnt kind of smell to it. It's fine, I guess it's just the way these cases smell.

that's a case, not an electrical piece of equipment.

What you're probably smelling is cigarette smoke residue.

anonymous02282011 · #8 08-16-2011, 11:04 AM

Quote:

Originally Posted by TF Ghost

So far it's only happened twice, and both times it was over 100 degrees in our practice spot. Each time it happened we smelled it within 30-45 minutes of playing, and we've played for 2+hrs many times without issue...

I guess you could just wait until your amp catches fire. Just make sure you take pics and update the thread.

Some component (resistor, etc) is malfunctioning and overheating. You might be smelling it burning up, or it burning surrounding components, possibly the circuit board.

It's probably a simple fix. Usually when you open up an amp with a burned out component, you can spot it right away because of the whole burning thing. Yea, it will look charred and black.

Fire Bad.

Good luck

Waffles and Scotch · #9 08-16-2011, 11:28 AM

Quote:

Originally Posted by adbass

I guess you could just wait until your amp catches fire. Just make sure you take pics and update the thread.

Some component (resistor, etc) is malfunctioning and overheating. You might be smelling it burning up, or it burning surrounding components, possibly the the circuit board.

It's probably a simple fix. Usually when you open up an amp with a burned out component, you can spot it right away because of the whole burning thing. Yea, it will look charred and black.

Fire Bad.

Good luck

Thanks! That's what I was looking for - some info more detailed than everyone saying "your amp is too hot and melting your case", or "your amp is failing and will catch fire.". I'll have it checked out. Appreciate the info.

beans-on-toast · #10 08-16-2011, 11:41 AM

The amp was designed to work with the vents unblocked and free and clear in a reasonable temperature environment. Otherwise, the heat is not going to dissipate and components such as the output power transistors can be damaged.

If the rack case is not providing at least 4" around the vents or if the back is sealed, you are asking for problems.

When it is hot, I use a small 8" stand alone fan that I got from the hardware store. It helps circulate the air and keeps things cooler.

This is from the M6 manual:

Do not block any ventilation openings on the rear or top of the amplifier. Do not impede ventilation by placing objects on top of the amplifier which extend past the rear edge of its cabinet.

Waffles and Scotch · #11 08-16-2011, 11:49 AM

Quote:

Originally Posted by beans-on-toast

When it is hot, I use a small 8" stand alone fan that I got from the hardware store. It helps circulate the air and keeps things cooler.

That's a good idea. Nothing ever blocks the vents (while it's running or cooling down), and the person that installed the amp in the Gator case is an authorized Mesa-Boogie repair tech, so although the Gator case extends a couple inches past the rear of the Mesa case, I'm guessing it's sufficiently ventilated. I'll have it checked out regardless since it's under warranty, but I think I'll try using an external fan when it's really hot, regardless of the outcome.

R Baer · #12 08-16-2011, 01:57 PM

Rules for Musical Instrument Amplification - Rule #14 - A burning smell coming from you, or your amp is NEVER a good thing.

bgavin · #13 08-17-2011, 06:57 AM

Probably a capacitor burning up.
I see a lot of computer system boards with the same smell and root cause.

A recap with premium components is money well spent.. especially if done before circuit damage sets in.

mpdd · #14 08-17-2011, 10:22 AM

i have convinced myself that the subtle smell is cat dandruff/hair or reactivated cigarette smoke since i don't get it all the time, but i'm going to turn up the fan on my head and see if it disappears

Venom of God · #15 08-17-2011, 10:26 AM

I have my SVT3 inside a Gator case and have never once noticed any kind of smell coming from it at all. I agree with everyone else- get that looked at.

Just to be sure though, it isn't just your cab getting super hot and putting out that smell that cranked speakers sometimes put out is it? I remember my stereo did it a lot as a young teenager and smelt it again recently when a new PA we got did it. I assume it is the speakers 'burning in' or something..?

Waffles and Scotch · #16 08-17-2011, 10:53 AM

Quote:

Originally Posted by Venom of God

I have my SVT3 inside a Gator case and have never once noticed any kind of smell coming from it at all. I agree with everyone else- get that looked at.

Just to be sure though, it isn't just your cab getting super hot and putting out that smell that cranked speakers sometimes put out is it? I remember my stereo did it a lot as a young teenager and smelt it again recently when a new PA we got did it. I assume it is the speakers 'burning in' or something..?

Good question! I have no idea. We narrowed the smell down to my rig, but I never thought to check the speakers. The amp was blazing hot (I had sweat on my fingers and it evaporated within 3-4 seconds of touching it), and the smell wasn't very strong, just a slight burning/melting/plastic smell, so we all just assumed it was the amp melting the plastic case ever so slightly. We moved to a new place with AC and I haven't been able to reproduce it. It only happened twice when it was 100+ degrees in the practice space, and went away when I turned the gain down.

It also might be worthwhile noting that I had the amp at concert-level volume, and neither the amp nor speakers have ever operated at that level in an environment that hot before (unless Mesa, Hartke or GK do that type of stuff in their QC).

Ric5 · #17 08-17-2011, 10:59 AM

It could be dust burning. Get a can of compressed air and blow out the dust. Also make sure that air circulates through the amp. Don't block vents. Also try an extra clip on fan to move more air through the amp. Also to make sure it is your amp feel for heat with your hand around the outside of the amp.

will33 · #18 08-17-2011, 11:00 AM

Your amp is blazing hot, it stinks and it's under warranty......

Good God, get it looked at before you destroy it and stop contemplating cats and cigarettes.

BurningSkies · #19 08-17-2011, 11:13 AM

Quote:

Originally Posted by will33

Your amp is blazing hot, it stinks and it's under warranty......

Good God, get it looked at before you destroy it and stop contemplating cats and cigarettes.

+1. I guess anything not to deal with an issue...sort of like when your car is making noises and you turn up the radio...or when your car wants to overheat so you drive with the heat and fan cranked all the way?

will33 · #20 08-17-2011, 11:24 AM

Quote:

Originally Posted by BurningSkies

+1. I guess anything not to deal with an issue...sort of like when your car is making noises and you turn up the radio...or when your car wants to overheat so you drive with the heat and fan cranked all the way?

Yeah, like that. Cheap fixes become expensive problems when ignored.