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will a low 60Hz harmonic hum wear out my speakers?

Hi everyone,
I have what is most likely a noob question: I have a nice sounding system consisting of a digital source (newly acquired Oppo BDP 95), a Quad 99 and Quad 909 pre-amp/amp set and Usher tower speakers. The amp generates a continuous, low hum audible in the tweeters. It is only audible with the ear next to the driver, and not an issue in listening. I like to keep everything always on, which is the recommendation I got from Quad and makes sense (it also sounds a lot better to my ears then when turned on fresh and cold). All would be good, but I wonder: in time, will that constant hum wear out or age my tweeters? It is after all the equivalent of constantly playing them but at a very, very low volume. Is this a real concern, or am I being paranoid here?
The issue of what causes the hum and how to get rid of it has been discussed and explored at length without a solution. It is probably the fact that the Quad does not have much in the way of insulation and signal cleaning (built that way) and no amount of power conditioning (I tried) or outlet-plugged signal cleaners etc etc (tried them all) gets rid of it.
Thank you in advance for any advice.
roc_doc

Showing 8 responses by roc_doc

roc_doc OP
55 posts
 
Thanks Al,
I was not going to attempt anything cavalier wiring-wise myself, I have neither the know-how nor the courage...
Indeed, if the answer to the original question regarding damage is no, then I am a lot less concerned. My worry was not about the electronics and the amount of power being sucked in, but actually (and likely simplistically) about mechanical wearing off of the driver membranes, given the constant movement to make that noise. Does that make any sense?
roc_doc OP
55 posts
 
Thanks folks
Yes, better shielding on the ICs is definitely something I am considering.
Unsound, what do you mean by having an odd number of grounded connections? Can you explain?
Thanks!
roc_doc OP
55 posts
 
Thank you everyone.
Elizabeth, yes, if it is so common I am a lot less worried.
Stingreen, obviously it IS wearing me out :)
Winoguy, I don't think it's 60Hz, it sounds a lot higher, but I'm wondering about a harmonic? It could be something else, of course.
One interesting thing about this, after lifting power cord grounds, trying all the power clears I could find, changing speaker cables etc etc ETC, is that it is very responsive to the kind of interconnects hooked between the pre-amp and the amp. In fact, the buzz is a lot louder if the amp is on with no interconnects hooked up to it, and quiets down some when I connect something to it. It can also be made louder by BAD interconnects. So, I should probably keep exploring (and spending, oy…) the interconnect issue.
Thanks everyone for chiming in. The immediate issue really is, if sonically I'm OK living with this, will it damage stuff downstream (ie the speakers)? If indeed it does not, there is much less urgency to this.
roc_doc OP
55 posts
 
hi,
Thanks all again. Geared4me, that is an interesting thought - I did talk to the Quad folks about this, and they actually said NOT to do that - they said there is a risk that the amp would get overloaded. It was one of the solutions I entertained, and I tried it briefly. While the buzz did not disappear it seemed to get lower. Are you using both the quad link and interconnects without a problem, I gather?
roc_doc OP
55 posts
 
Ojgalli,
I tried a different amp in the same set-up and no, there was no buzz at all. I also disconnected everything upstream and the buzz was there with only the amp connected to the speakers.
So, yes, given that the connections into the amp change this BUT it is something that clearly originates in the amp, we conclude that... ??
roc_doc OP
55 posts
 
Elizabeth,
I am sure SOMETHING would be audible if you try hard enough. In my work, we often say that all you need to do to find an abnormality is to make your diagnostic test more and more sensitive, you will find something...
But as stated before, since this is more easily audible than I am completely comfortable with (1 foot away if the room is quiet) I was concerned with what it may do to the speakers.
Again, not that I don't enjoy my over-intellectual paranoia, but if this is indeed common and not a cause for damage over the long run, I'm fine with it, I'll adopt the buzz as a pet... But if it can be done away with, I would prefer it...
roc_doc OP
55 posts
 
Geared4me, I saw the same review - I think it was the Stereotimes. It is very possible that Quad will automatically give you a response that is in line with their legal liabilities etc having to do with tested safety configurations. I would tend to trust Walter - he knows what he's talking about. I will try that again, but last time it did not abolish the buzz, sadly.
It seems that several folks are suggesting not to worry about said buzz, so I'll live with it if it doesn't go away.
roc_doc OP
55 posts
 
Quick update: I remember why I didn't do the Quadlink and interconnects at the same time - makes the buzz a lot louder!
Damn it, now it's like an annoying puzzle. There is definitely something here that has something to do with the connections and insulation at the input-output area, no?
Does it mean anything that the left channel has a louder buzz, and the speaker connection to it is closer to the interconnect (and quadlink) connection area on the amp?
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