2. amps-preamps
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Amp heat sinks are ringing

I have been working to reduce the slap echo in my room by using quick hand claps, and various foam panels to attenuate the noise. I have discovered that my Classe CAM 200 monoblock heat sinks are actually ringing- they can be excited by handclaps, and heard across the room. There are 10 heat sinks per amp, about 2" deep by 8" high. Running my fingers along the heatsinks makes them ring like a bell!

I am concerned that this ringing might be excited when I am listening to the system, and may add extra treble noise.

Does anyone have any suggestions for damping out the noise? I am concerned about using a material that can withstand the heat, and not impede the airflow?

thanks for your help!
gnobber
blkadr
739 posts
 
A while back I read a review of the Belles 150 Hot Rod amp at soundstage.com in which they addressed heat sink vibration. Dont remember what they used, but you might check it out.
timo's avatar
timo
610 posts
 
You may want to try placing some "felt-type" pads between the heatsinks on your amps. This should damp out some of the ringing and cost you next to nothing! However, there are probably better and more effective methods that may cost more.
zoya
120 posts
 
Gnobber, how hot do the heatsinks normally get? If they stay cool - than you can play with some damping material. But if they run hot, anything you place on or around heatsinks will impede cooling and can cause damage to the output devices. Perhups, placing the amp in the separate room and running the cables to the speakers through the wall may be an answer.
rhljazz
1,253 posts
 
I had the same problem with a CA300 and I used MDF blocks the same length and width of the heat sinks and placed on top of the fins and then weighted down with brass cones. I painted the MDF black so it didn't look bad. The fins never got hot enough to mar the paint or the wood and the difference was dramatic, much better focus and imaging and reduced some of the glare spots through the treble.
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