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D75A - noise


4 replies to this topic

#1 nielsenr

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Posted 13 November 2005 - 04:09 PM

Hi everyone.

I have recently puchased a Crown D75-A amplifier to power my Dynaudio Acoustics BM-6 monitors. I must say it sounds sweet!

However, I thought the D75-A was supposed to be completely quite, but I have found that my D75-A isn't. It has a low "buzzing" sound. Nothing to serious but enough to annoy me because I have the amplifier on my desk. The sound decreases when I put some pressure on top of the amplifier with my hand.

Is this normal for the D75-A or is there somthing wrong with mine?

Best regards, Rasmus Nielsen.

#2 DGlass

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Posted 14 November 2005 - 09:35 AM

This sounds like a mechanical vibration that is being induced by the AC transformer. There isn't much you can do about it except to apply a little pressure to the lid, as you have already found. Some are quieter than others in free space. Placing a D75 in a rack, with equipment touching it, usually elevates the mechanical noise as well.

#3 Ancient Audoiphile

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Posted 15 November 2005 - 07:11 PM

Hi David

Unfortunately, I have the same problem with my three D-75A amplifiers. A faint, 60 hertz mechanical buzzing sound coming from the AC transformers. I thought about popping the bottom cover and wedging a small piece of foam rubber between the transformer and the bottom cover.

Is this a good idea? Or am I just buying a whole lot of trouble with heating issues?

Oh, I am sure your wondering what am powering with a K2, K1 and three D-75A amplifiers. For now, my system is a 15" quad amplified 4-way. But, eventually I will get around to adding the sub-woofers.

Just go to the following site and read a complete description of what I am building.

http://www.audioheritage.org/html/perspect.../audiophile.htm

Thanks

#4 DGlass

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Posted 16 November 2005 - 02:37 PM

QUOTE(Ancient Audoiphile @ Nov 15 2005, 07:11 PM)
Hi David

Unfortunately, I have the same problem with my three D-75A amplifiers. A faint, 60 hertz mechanical buzzing sound coming from the AC transformers. I thought about popping the bottom cover and wedging a small piece of foam rubber between the transformer and the bottom cover.

Is this a good idea? Or am I just buying a whole lot of trouble with heating issues?

Oh, I am sure your wondering what am powering with a K2, K1 and three D-75A amplifiers. For now, my system is a 15" quad amplified 4-way. But, eventually I will get around to adding the sub-woofers.

Just go to the following site and read a complete description of what I am building.

http://www.audioheritage.org/html/perspect.../audiophile.htm

Thanks
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You shouldn't have a problem adding a piece of foam but make sure it won't melt or ignite if it gets hot. I can't guarantee that this will fix it completely either.

#5 Icha

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Posted Today, 03:21 AM

I have the same issue here, gets worse if it's racked, sounds like a bumblebee. Since I bought it under warranty - I sent it back, and they sent it back without fixing anything! Worst of all is that they didn't even have the decency to put all the screws back properly! So I'm sending it back for "repair" again today. The question is, will they actually repair this fault if it's still under warranty or it it just my bad luck?

Regards
Andrew Ainslie