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
I wonder if one of Herbie's products (Hal-o) could be cut to work for you. They are at least tube-heat proof. I've never used them to hear how effective they are, but others seem to really like them.

Yours are not the only amps with this problem; at a shop long time ago, I had clapped in an audition room to check for slap echo. Something else was ringing - metallic, too. After a few test claps to narrow down who was talking back, we found a pair of Mark Levenson ML-2s on the other side of the room with some huge, lively heat sinks.

Good Luck!
To Pmkalby:

I received a reply from Armin at Classe, who says

"We have done some testing with regards to this concern, and I can tell you that the ringing is Not transposed into the sound from the speakers.

It is also very difficult to make the heatsinks ring when playing music unless the CAM-200 is directly in front of the speaker, and even in that scenario the ringing is very limited, and is not transposed to the speakers."

Nonetheless, I did cut up some wine corks into small trapezoidal wedges, and pushed them into the top and bottom of each heat sink pair. It seems to cut down the ringing when I clap, and has so far survived a loud listening session where the amps got quite hot. There is still a substantial airflow path to allow convection to work. This should take care of any noise that might have come through the amp and speakers, as well as any ringing that comes straight through the air to me.

thanks again for everyone's great ideas on this question!
Excellent idea Gnobber, I would continue to acquire wine corks. Even if it doesn't stop the ringing you won't care!