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WANTED! P3A Amp heatsinks!

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This may be a long shot but is anyone out there blessed with two heatsinks that are the right size (and preferably pre-tapped) for 2 P3A boards? [Around 1Deg C per Watt 170mm*80mm]

I would be greatful for any replies - I'm from the UK so preferably no replies from too far away (unless you know some way to post heavy items gravity free!)

Thanks for looking



If you can't find anything more exactly suitable, I have some heatsinks available. Here's a description I gave to someone else:

"My calculations and comparisons with other heatsinks seem to indicate they'd be more like 1C/W, though. That is conservative actually, as they look pretty identical to the one that is rated at 0.9 or 0.58C/W in the (1997!) RS catalogue I have. They are 150 x 200 mm (the 0.9C/W in RS was/is 125x200, and the 0.58 C/W was/is larger than these). There are 29 fins which run parallel with the short dimension which are 25mm long (actually 21mm ignoring the base thickness). I'd guess at 0.8 C/W or there abouts... They have a threaded hole near each corner (so can easily be turned into square enclosures with a little aluminium angle), and are drilled and tapped (twice) for transistors either side of the midpoint of a line running down the middle. Ideal for flatpacks, but TO-3s would require more drilling or a bracket. My only reservation with them is that they are powder coated (black) rather than anodised, and if they are dropped the coating on the edges of the fins can chip."

A tenner each, I'm in London.

Cheers, Jake
Cheers for the reply - I've been looking for a while now, is there any chance you could post or email me a pic?

...so far they sound interesting for the price, especially considering RS want's something like £25-£45 for this sort of Deg C/Watt


Sorry, no pics and no way to take any.

Rarkov did a render from the description which I've tried to attach. Pretty damn acccurate, if you can imagine them black!


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I highly recommend dealing from this guy - I bought two of these heatsinks and paid via PayPal and they were at my house before 9 the next morning!

May I say a pleasure to deal with you - also if you ever have anything else laying around be sure to post on the forum and email me first ;) .

If anyone has any queries buying goods over this forum I would happily reply emails with regards to the good service I received.

I agree. Got my sinks today. They're great. They a very slightly chipped but a permenant marker has completely hidden that!

Very quick postage!

Just thoughyt I'd say that it was certainly not poor packaging that caused chips...It took me 30mins to get into and that is NO joke. I was late taking my girlfriend to work!!!

Thanks Jake!!!
Thanks Annex and Rarkov,

Rarkov - if you want replacements for the chipped ones, let me know. I did check them before sending, but I guess I didn't look closely enough. Apologies anyway, but if you do want replacements get in touch.

(that is the down side I warned of of the powder coating/paint, whatever they used appears not to be totally robust on the fin ends, and slight chips occur pretty easily. I once stacked up a whole bunch to see what my planned case would look like, it collapsed and I have a bunch of chipped ones. As you say, luckily a marker pen makes it invisible to anything but microscopic attention.)

Cheers, Jake
Hi Jake,

Don't be silly - I couldn't get them this cheap anywhere else! They're great! I've planned them so that everything fits in perfectly (500VA tranny, 4x6.8mF caps, 2x35A rectifiers, circuit, 4xMOSFETS)...

Anyway - It's only maplins I cause hell for! (Our version of Radio Shack if non-UKians didn't know)

I'm trying to think of a nice thin plank of wood to cover the top,bottom,front and back with...Not sure yet...It may well be clad with aluminium yet!

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