A possibility for compact heatsinking - Xeon Wind Tunnel! (Pics!)

[OddOne]

Since I need a better thermal solution than the heatsink I have for my LM4780s, I snagged some Xeon Wind Tunnel heatsinks off eBay.

Check these suckers out...



This is the package you get with a Xeon processor - the heatsink in a little acrylic shipping box (save the box - it's a great tiny-parts bin!), an 80mm 12VDC fan with a tach lead (standard 3-pin motherboard header), a base cradle, a tunnel-like cover, a fan bracket, and a bag o' hardware.

Surprisingly enough, the bag o' hardware contains a small syringe which in turn contains a little bit of micronized-silver thermal goo. Don't know how it compares against the king of thermal compounds - Artic Silver - but hey, I'll use it.




The heatsink itself is a thin-fin design, with the fins inserted into slots cut into the base. The base itself is about 3/8" thick, and hefty - a good pound or so. The center fins are, as the pic shows, copper.




The basic idea is to mount the cradle onto the motherboard's heatsink holes (which generally are aligned with studs on the case) and set the heatsink into it and on top of the processor. Two metal clamps secure heatsink into cradle.




The top cover then snaps into place around and over the heatsink.




Once the cover's in place the reason for the "wind tunnel" moniker is obvious. It has a detachable top opening that can be used to mount the fan over the heatsink in case you need to blow air in from the top and out both sides, but that gets left in place if you use the next part...




The kit includes a small plastic part that the fan attaches to, and this in turn snaps onto one end of the cover to form the wind tunnel. This kind of arrangement seems like it'd lend itself VERY well to a ducted internal-heatsink design for an amplifier - low profile and active cooling in one package.




Once the fan is attached to the end, you have your wind tunnel.




My only real complaint about the unit is the milling on the heatsink - it's rough milled and has grooving that a fingernail can feel. For use as a processor heatsink it'd really work better if lapped with some fine sandpaper proir to installation. The same can be said for use as a chip-amp heatsink.




Another view of the heatsink's base finish, before I stuck the second one into the cradle.




And finally, here's what I intend to do with the ones I have: bolt paralleled LM4780 amp modules to 'em!


The design of the cradle makes it possible to mount the heatsink by its plastic cradle and let the heatsink itself float electrically, and this makes it possible to secure the heatsink somewhere and mount one heat-generating part to it without having to worry about insulating it. Better thermal transfer = longer component life and better operation under heavy loads!



Once I've had a chance to bolt the 4780s to these and run some tests I'll post my thoughts on whether and how well these work...

oO

[Damon Hill]

What are the dimensions of the base area?

[joensd]

I like (and used) these for a gainclone.
One channel on each side and a little 1.6" or 2.36" fan for airflow.

[joensd]

Another view where you see it´s actually two parts that slip together.

[S.C]

Originally posted by joensd
Another view where you see it´s actually two parts that slip together.

I'm thinking what will happen when someone customize a chassis for this heatsink..... It will be a cool looking amp.

[OddOne]

Originally posted by joensd
I like (and used) these for a gainclone.
One channel on each side and a little 1.6" or 2.36" fan for airflow.

Who makes that and how much they sell for?

oO

[jackinnj]

be mindful that you won't need more than 2 oC/W at the max for one LM3875 -- even in the TF (insulated) package.

i think that it's a very nice solution, however -- if you can source the C/W ratings then perhaps you could use multi-LM3886's on one heat sink.

in fact, the best solutions seem to come from either your experience or surplus or end-of-the-run sinks for big SCR's.

[OddOne]

I spent a couple hours lapping the heatsink base with 600-grit and 1200-grit paper with a chaser of Brasso.

The finish is a LOT better now...



It's not mirror finish, but a mirror finish is overkill in this application. Lapping it this much, however, should be good for a detectable decrease in thermal resistance.

oO

[karma]

good thing i saved this one now i wana try it

[neutron7]

fans on a gainclone???? SACRILIGE! its supposed to be quiet, its not like you are trying to heatsink a 500W amp or something.

use the cool heatsinks by all means but not the fan!

just turn it upwards in your desighn and let lovely silent convection do its work