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-   -   fabulous deal on chipamp heatsinks!!! (

Jim Karr 15th January 2005 02:29 PM

fabulous deal on chipamp heatsinks!!!
I just found the perfect, very affordable heatsink assembly for amps using LM3875 or LM3876.

MCM in Ohio has a computer heatsink cube with a copper insert, plus a 12vDC fan attached to it for $5!!!!!!!!!!!!!

Go to, look up their part # 83-10371.

I bought one yesterday for a sample, now I'm back for a quantity!

tommak 15th January 2005 03:07 PM

Take the comma off the end of the link.
If you click on the link above, it doesn't work, due to the attached comma "," at the end.

Jim Karr 15th January 2005 03:13 PM

oops, I'm an idiot

markp 15th January 2005 03:35 PM

That should be good for about 75 watts as the AMD cpu is a little over 75 watts with a temperature of ~45C.

demogorgon 15th January 2005 04:17 PM

would you know..

i actually own one of theese.. the only problem with computer heatsinks is that they have to have a fan on them, because the fins are too close to eatch other to allow a good airflow through them.

and i like the sound of good music better than the sound of a irritating buzzing fan. not to nemption that computer fans near audio equipment tend to make their precense know trough your speakers a well. i have large problems with this in my room as the computer and amp is lying about 30-35 cm away from each other, and i use a lot of fans..

zBuff 15th January 2005 09:53 PM

I was going to use CPU heatsinks for my chipamp heatsinks also, I've got labout 10 extra heatsinks lying around since I've built quite a few small form factor cases, which always have there own cooling components.

Demogorgon, so do u think CPU heatsinks aren't very appropriate, does convection heat dissipation not work very well with them because of the small fin spacing distance?

I wasn't intending on using fans on mine in any case.

Another problem that could occur is resonance with such small fin sizing.

From what I've seen of other ppls chipamps the heat dissipation qualities of a CPU heatsink should be plenty.

What is the optimal operating temperature of these chips anyway? I tried looking over the LM3875 datasheet to no avail. Maximum temperature of 165 C is pretty damn high when the thermal cutoff kicks in.

demogorgon 15th January 2005 11:27 PM

zBuff: yes, that is exactly what i mean. i know from having tested computer heatsinks with passive cooling before.

and note altso that all heatsinks not meant for having fans on them have dramaticly more distance between the finns.

azira 17th January 2005 05:22 PM

I used a Foxconn heatsink that looked almost exactly like this for my Zen amp which dissipates about 50-watts idleing. One really cool 'feature' of this heatsink is the integrated heat spreader which is screwed in place. If you remove it and keep the screws you have built in mounting holes for your chips that should be just about at the perfect distance for pin clearance. You could probably mount 4 channels on one heatsink with no issues. Undervoltage the fan and it should be fairly quiet although not -dead- quiet.

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