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large heatsink will be available by april or sooner

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This is the one by Conrad that many have used.
 

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Just to give a second reference of what several experts consider one of the best available free air convection amplifier heatsink profiles.

The Seifert KL-271 has been recommended for the Leach amp and sevearl PASS amps. There have been past group buys on diyAudio with black anodized coated production running ~$60 each.

There is also a 15" long KL-273, but the cost bump is much greater than the area increase.

http://www.diyaudio.com/forums/pass-labs/56087-heat-sink-gp-us-canada.html


With the fins oriented vertically, this heatsink measures 12" wide, 8" long, 3.25" thick, and has a 1/2" thick back plate. A singe 8" (200mm) length of this heat sink with black anodize and natural convection is rated for 0.18c/w or approximately 140-150 watts dissipation with a 25c temperature rise.

One of these would comfortably run a stereo Mini-Aleph. Two of these sinks would provide 0.09c/w of cooling that can dissipate approximately 280-300 watts and should be sufficient for a 100wpc Aleph-X monoblock or even an Aleph 2 monoblock.

Raising the heatsink 1"-2" off of the ground is important to start the "chimney effect" pumping of cool floor air through the fin tunnels fueled by heat energy. HEAT and MASS tansfer provides cooling, so you want to move the most cold air possible across the fins. A 6" to 8" high vertical fin heatsink provides enough pump transfer with a reasonable pre-heat inefficiency as you move up the heatsink away from the cool floor air. It is more efficient to use a longer than a wider heatsink beyond 6-8"
 

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Ex-Moderator R.I.P.
Joined 2005
I have this one
looks similar, apart from not having the more effective ribbed fins
please dont ask what i payed to get it
but, in its favour, its the most smooth a levelled back I have ever seen
usually you need machining to achieve such high level of precision
 

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thing is , is that heatsinkusa's 10.080 profile works superb for a pass f5 :)

DSC_0254.jpg


those are 7" high and biased at 1.4 amps never reach 40c in my 66f room and they are on a shelf with only 3" height clearance above .

so again for the naysayers . they WORK !!!

cheers Woody
 
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thing is , is that heatsinkusa's 10.080 profile works superb for a pass f5 :)

DSC_0254.jpg


those are 7" high and biased at 1.4 amps never reach 40c in my 66f room and they are on a shelf with only 3" height clearance above .

so again for the naysayers . they WORK !!!

cheers Woody

Nice looking amp and chassis! Have you described your chassis construction anywhere? Did you have the front and rear panels done out or DIY?
 
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