My amp gives off a smell...

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MatchBookNotes

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Right, My old traynor, once i get it worked up and playing for like a half hour straight it starts to emit an odour, almost like when you're soldering? Is this just hte tubes being thoroughly warmed up? Should I put a fan on the back of the amp?
 
It could be the transformer overheating, or it could be an output tube running far too hot. Either way, have a technician look at it tout de suite.
 
Certainly a good idea to get it checked, but it is not necessarily anything catastrophic. Stuff in there gets hot, and hot stuff stinks. But get it checked just to be sure.


Light

"Cowards can never be moral."
M.K. Gandhi
 
that sucks. I don't know whether to take it where i bought it or shell out the denero that i don't really have to long and mcdonalds. 86 an hour. ouch.
 
MatchBookNotes said:
shell out the denero that i don't really have to long and mcdonalds. 86 an hour. ouch.
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Are they good? Because if they are, it is worth it. Someone who doesn't know what they are doing will miss things, and fixing your amp will be more expensive after you blow a tranny will be more expensive than if you had taken it to the right place in the first place. Never skimp on repair folks (which is easy for me to say, as my shop is primarily a great repair shop).


Light

"Cowards can never be moral."
M.K. Gandhi
 
I have a Traynor Customer Special 50H (or something like that) I notice a weird smell coming from it all the time too. its like its ready to blow or something.
 
Light said:
fixing your amp will be more expensive after you blow a tranny
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um....how does what you engage in behind close doors affect the repair cost of an amp?


Sorry. Couldn't resist.
 
MatchBookNotes said:
Right, My old traynor, once i get it worked up and playing for like a half hour straight it starts to emit an odour, almost like when you're soldering? Is this just hte tubes being thoroughly warmed up? Should I put a fan on the back of the amp?
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Just guessing - the electrolytic power supply capacitors I mentioned before are leaky (electrically) and thus drawing too much current from the power transformer. The smell could be overheating of the caps, the power transformer, or the diodes in between, which are solid state diodes according the the schematic.

Tom
 
I had an Ampeg Reverberocket that gave off that 'new amp' smell from the vinyl glue for YEARS after about an hour of use. There was nothing wrong with it -- the glue was just really stinky. Is this a new occurrence?

The transformer running too hot is not something you can assess visually, but you should definitely look at your power tubes. If any of the plates are turning red, they're either biased too hot or you're about to lose one. Retube now as a blown power tube can make for costly repairs.
 
Oancient1 said:
Just guessing - the electrolytic power supply capacitors I mentioned before are leaky (electrically) and thus drawing too much current from the power transformer. The smell could be overheating of the caps,
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sorry but this is just plain wrong... a cap does not have any current draw in the sense of useing it... it is essentially a battery storeing for msec the charge and then releasing... in effect smoothing the supply... when supply caps let go the short... the only state between good and short is when the dry out and you get hum... that smoothing effect is no longer there... and they dont heat up... sorry to disabuse you of whatever you thought but there it is...
 
MatchBookNotes said:
Right, My old traynor, once i get it worked up and playing for like a half hour straight it starts to emit an odour, almost like when you're soldering? Is this just hte tubes being thoroughly warmed up? Should I put a fan on the back of the amp?
Click to expand...

can we assume that this represents a change??? if so then i'ld take it to the doctor... likely suspects are the power tranny/output tranny/and output tubes... and it doesn't sound like you have the skill set to do it yourself so take it to someone who knows amps...
 
MatchBookNotes said:
Right, My old traynor, once i get it worked up and playing for like a half hour straight it starts to emit an odour, almost like when you're soldering? Is this just hte tubes being thoroughly warmed up? Should I put a fan on the back of the amp?
Click to expand...

Check the simple stuff first: look at the tubes and see if they are clean. I had a similar situation once; something plastic had melted on one of my power tubes and every time it heated up, the plastic would remelt and smoke a little bit.
 
arcaxis said:
Electrolytics can get leaky and not be totally shorted. Any as they get leaky they filter as well, thus more hum.
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i've seen leaky caps... but not in tube guitar amps where supply voltages can run up into the 6-700Varea... IME... the caps that leak are more what you find used as interstage coupling caps... and in tone circuits... and if the hum has increased it deffinately is filtering less... YMMV...
 
dementedchord said:
sorry but this is just plain wrong... a cap does not have any current draw in the sense of useing it... it is essentially a battery storeing for msec the charge and then releasing... in effect smoothing the supply... when supply caps let go the short... the only state between good and short is when the dry out and you get hum... that smoothing effect is no longer there... and they dont heat up... sorry to disabuse you of whatever you thought but there it is...
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No worries about disabusing this old fart -- my days on the bench being smart are way in the past. Just don't say anything bad about my cat. He might bite you.

Do note that I said "just guessing" . But a quick look at wikipedia did verify (as much wiki can) that my memory was correct about electrolytics having some leakage current and equivalent series resistance (ESR), and a personal post elsewhere said that evaporation of the electrolyte over time can increase ESR and cause capacitor heating. Finding info on the net proves nothing of course -- you could be totally correct regarding the Traynor. Just the same, I would change the caps if they are original, as is recommended with any amp of that vintage. And until I could do that I would make darn sure that the fuse is the correct value and keep a fire extinguisher handy when using it.

Tom
 
Oancient1 said:
But a quick look at wikipedia did verify (as much wiki can) that my memory was correct about electrolytics having some leakage current and equivalent series resistance (ESR), and a personal post elsewhere said that evaporation of the electrolyte over time can increase ESR and cause capacitor heating.
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Series resistance is not a leakage path; it's in series with the ideal capacitor, innit? Parallel resistance would be a leakage path around the capacitor.
 
MatchBookNotes said:
Right, My old traynor, once i get it worked up and playing for like a half hour straight it starts to emit an odour, almost like when you're soldering? Is this just hte tubes being thoroughly warmed up? Should I put a fan on the back of the amp?
Click to expand...

tube amps always have a smell when they are heated (epespecially new) and 20 minuites is about the time it takes for a tube amp to warm up good. The smell will wear off after you have had it a while.
You do not want to use a fan to cool of the tubes because a tube amp performs at its best when the tubes get hot.
 
Roguetitan said:
You do not want to use a fan to cool of the tubes because a tube amp performs at its best when the tubes get hot.
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Depends on the design of the cabinet. There is such a thing as too hot, in which case a fan (one which does not blow directly on the tubes) is a good idea. But most amps don't need them. It's a good idea on a lot of AC30s, though, as it gets crowded in there.


Light

"Cowards can never be moral."
M.K. Gandhi
 
Light said:
Depends on the design of the cabinet. There is such a thing as too hot, in which case a fan (one which does not blow directly on the tubes) is a good idea. But most amps don't need them. It's a good idea on a lot of AC30s, though, as it gets crowded in there.


Light

"Cowards can never be moral."
M.K. Gandhi
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I can see using a fan for diffusing heat for a rack mount amp that shares a rack with other equipment. other than that I have really never personally seen any need for a fan on a tube amp.
 
MatchBookNotes said:
Right, My old traynor, once i get it worked up and playing for like a half hour straight it starts to emit an odour, almost like when you're soldering?
Click to expand...

Well, if it's old, it's probably dust burning.

I don't know....
 
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