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How deadly is transformer hummm...

Hello Folks,

I recently collected a lightly used (less than 50 hours) Dennis Had - Inspire - "Fire-Bottle." Within some few days, I noticed a humm emerging from somewhere within the chassis of the unit. As the unit was sold in "perfect" condition, I found the humm startling. Mind you, I've discovered absolutely no evidence confirming the sound is compromised; I mostly hear the sound within a couple feet of the amp, when the surrounding environment is silent.

This amp truly is a work of art. Nevertheless, I am now dealing with this 'humm' sound. I bought an Emotiva CMX-2 as a way to deal with DC offset, and this has not impacted the situation to any detectable improvement. Perhaps there is a slight improvement, but negligible. What to do?? Should I just relax, shake it off, and assume the amp will live well, or a down-the-road transformer replacement will simply become part of my experience with this amp? Should I put pressure on the seller to "right" the situation? He claimed, as I asked him, that it was the quietest amp he's ever owned. His add boasted that the fire-bottle exceeded amps from Pass Labs, a Cherry Amp, and one other that escapes memory. The seller has presented all of his communication in the manner of friendly professional etiquette. 

Your thoughts are appreciated. 
listening99
listening99 OP
172 posts
 
By the way, the title of the original post should have included a question mark, and slightly more qualified phrasing:

"How deadly is transformer hummm, to the amp itself...[?]"
bdgregory
1,715 posts
 
Is it a mechanical hum (ie, xformer against chassis) or electronic hum coming from speakers? The former may be as simple as mounting screws needing tightening.
zm
121 posts
 
I have a Line-Magnetic LM-218ia that emits an audible transformer buzz, which you can definitely hear anytime you are standing by the amp while it's on. I understand from fellow owners that this is quite common to LM amps, and harmless.  I guess I assumed it was the price of admission for using an SET amp with massive transformers, and since I can't hear it while listening, never bothered me.

As far as this situation, when the seller claimed the amp was the quietest he had owned, I would have assumed he was referring to electronic buzz you can hear from the speakers.  I would assume it's within your right to return it if you wish, since this wasn't disclosed, but it also seems to me to possibly be within the normal operating parameters of the amp?
yeti42's avatar
yeti42
287 posts
 
Naim amps have a reputation for humming too. I’ve had a couple of complete system from them and some transformers have hummed whilst others haven’t. A couple have even stopped humming after a while but it’s never done any of them or the music any harm.
brownsfan
1,508 posts
 
I recently had a hum coming from one of my amps.  The source was a bad tube.  I'd want to rule out other sources of hum before returning the amp.  I was advised to check my tubes for unusual microphonics, which I found to be present.  I quickly identified the offending tube.  Replaced the tube and no more hum.   
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