CPU cooler for amplifier

[Circlotron]

I have often thought about using a CPU cooler as an amplifier heatsink because a lot of them are moderately priced, and because the heatsink itself is fairly compact. Also, it would be quite easy to run a live heatsink i.e. no thermal washer with it's consequent (sometimes quite high) temperature drop. This translates to a cooler running fet / transistor or alternatively you can run it harder for the same temperature rise. Of course there is the noise issue from the fan, but that is not always a problem given that in some situations the noise level is already quite high e.g. sound reinforcement.

Anyway I was looking at a comparison of cooler types at http://www.tomshardware.com/ and there was this one cooler that stood head and shoulders above the crowd. Just look at that 3/8 inch thick copper base! They are pretty expensive at about $80US but they would seem to represent the ulimate in compact air cooling. Certainly a very advanced device.
http://www17.tomshardware.com/cpu/20...cooler-29.html
http://www.cluboverclocker.com/revie...ftech_mc462-a/
http://www.swiftnets.com/

[Mark A. Gulbrandsen]

I would agree if the entire thing was copper but its not. There will be at least some thermal resistance where the alumnium parts join the copper plate. No way is it worth 80 bucks IMHO. You are almost into the realm of water cooling your CPU for that much $$.
Mark

[OddOne]

Yes, it is possible to use processor cooling units for amplifiers. And, given that most high-end coolers are built around the notion of the heat source producing 50-100 watts of heat continuously, as long as you're not exceeding that kind of device dissipation a processor cooler would work well.

The problem comes when you're talking about multiple devices, each dropping a hundred watts or more into their heatsink. In such a context, processor coolers are very cost-ineffective.

What I'd like to see is the same kind of engineering applied to larger heatsinks that would be ore suited to amplifiers. A silver-pin heatsink a foot-square could handle an amazing amount of heat.

oO

[fmak]

This is precisely what you don't want to do. Most CPU coolers are bloody noisy and don't pay attention to so called 19db or 28dB fans. They still intrude. Heat pipes also make a bubbling noise.

I have just spent a lot of time making a quieter PC. What I have found is that reducing fan speed has the greatest benefit, giving already quiet fans. Half speed or less is needed and this reduces cooling capacity considerably. I have had to juggle processor type, fan type, casing insulation, fan speed and CPU/System temperatures!

I now have a 50dBC PC, and it still can be heard 1m away when you want to enjoy music.

[Christer]

I bought one of those Papst 18dB fans to replace the fan in
my computer PSU. After this I did some experiments using
a bench PSU and found that the original fan was just as silent
as the Papst if run on half the voltage (6V). I also noted that
the power rating of the Papst fan was only 25% of the rating
of the original fan. Now, if you run a 12V fan on 6V you get
25% of the power at 12V, so I guess it may be just as efficient
and as quiet to reduce the voltage instead of buying a silent
fan. Of course quality enters the equation, but at least the
Papst fans are of quite bad quality, or rather, there is quite
a big chance that you get one which makes a ticking mechanical
noise that shouldn't be there.

[mbroker]

For US$8.00 each plus shipping, you can have your very own copper spreader plate. See this post for more info. A cut and milled plate is $5.00 each, but you'll have to spend a while with a sander to buff the finish.

Used with a much less expensive heatsink and fan, I think you'll realize a similar performance.
Here's an "orb fan"
Here's a fairly beefy P4 heatsink and fan

You'd come out ahead from a money standpoint

My

Mark Broker

[Christer]

Originally posted by mbroker


Here's an "orb fan"
Here's a fairly beefy P4 heatsink and fan

Actually, the first one is not an Orb, but a Silent Systems Radial
Fin. I happen to have one of those in my PC.

[Fmaker]

What came to mind for myself when I started reading the original post was' trying to find some old Intel Slot one or AMD Slot A Heat sinks. Those CPU's were much larger and really created a lot more heat so they needed larger heatsinks. Trying to find a place that sells re-cycled computer parts, might be the way to go in finding heatsinks of that type. Probabably for a much better price also . Parts Express (in their catalog) sells a (I think it was a) 90mm fan that runs on 120 volts. Their are also computer parts stores that sell what are called fandapters or fan adapters. Makes it so you can use a larger fan and mount it on a smaller heat sink. That way you can run the fan at half speed and still get a decent air flow...... might cut down on the noise issue also
Like I said, just a thought
Try this link and see if there is something there that will work.
Price is better also

http://shop.store.yahoo.com/chipcooler/cpucoolzal.html

. A person could also do a search on:
http://www.pricewatch.com

[joensd]

Regarding that you need more than one of those CPU coolers I´d rather have a look at the professional forced convection coolers.
Fischer Elektronik for example have some nice and effective ones from 100W Pd up to ???.
I use a little tube for my LM3886 amplifier with a little 40*40mm fan. It´s basically the same as the "LAM1" from Fischer Elektronik. I bought it at ELV.
The bigger version (LAM2) is able to dissipate up to 250W with an effective fan and cost about 25,50€ at ELV.
If you need to dissipate more than that have a look at the "LA1" from Fischer.

Jens

[Greg Erskine]

Circlotron,

I'd be a little concerned about the reliability of fans. From my experience, the computer PSU fans are the first item to fail in computers. Granted the CPU fans seem more reliable, but how much more? A lump of aluminium would have a slight edge in the reliability stakes.

Having said all that, a fan run at half voltage would probably have a long life, (but I'd make sure I installed a thermal cut out just in case.)