Heatsink candidate for Class A?

CanAm Man · 16th September 2011, 12:08 AM

Sorry, but I could not find a recent Pass Labs thread associated with heatsinks, so here goes.

I recently purchased a pair of fan-shaped aluminum heatsinks on eBay from a U.S. supplier, for $55 + free shipping. They are massive aluminum. The seller quotes a 0.74 degree C/W spec, but I suspect that may be conservative. They may be a little "light" for an F5 build, but you'all may find them useful in other Class A designs. (I know it's probably heatsink "overkill", but I'll be using these in a Class D chipamp.) The mounting surface for the semi-conductors/components is almost mirror-like (very nice construction).

The seller's ad says he has more. Here's the info, if you'all are interested:

eBay - New & used electronics, cars, apparel, collectibles, sporting goods & more at low prices

...and no--the seller isn't my brother or uncle, or cousin......

Zen Mod · 16th September 2011, 04:50 AM

pair for one F5 channel , with plenty of bottom clearance

wrenchone · 16th September 2011, 05:03 AM

Bottom clearance - no saggy bottoms around here.. A breath of air from a slow fan might make those heat sinks very A-worthy.

Russellc · 16th September 2011, 10:48 AM

Quote:

Originally Posted by Zen Mod

pair for one F5 channel , with plenty of bottom clearance

Hee Hee....he said "bottom clearance"

Sorry, my back meds are kick'in in.

Russellc

buzzforb · 16th September 2011, 11:31 AM

I think someone sold you a polished engine block.

CanAm Man · 16th September 2011, 03:54 PM

Quote:

Originally Posted by buzzforb

I think someone sold you a polished engine block.

And they're HEAVIER than aluminum cylinder heads, for a small-block Chevrolet....!

P.S.--I'd agree..... with some light forced air movement around these, they ought to be very impressive. I'm using some reduced-speed fans on my F5 (with the large Conrad heatsinks), and my biggest challenge is getting the MOSFETs up to temp......

AudioSan · 09:33 PM

Quote:

Originally Posted by CanAm Man

Sorry, but I could not find a recent Pass Labs thread associated with heatsinks, so here goes.

I recently purchased a pair of fan-shaped aluminum heatsinks on eBay from a U.S. supplier, for $55 + free shipping. They are massive aluminum. The seller quotes a 0.74 degree C/W spec, but I suspect that may be conservative. They may be a little "light" for an F5 build, but you'all may find them useful in other Class A designs. (I know it's probably heatsink "overkill", but I'll be using these in a Class D chipamp.) The mounting surface for the semi-conductors/components is almost mirror-like (very nice construction).

The seller's ad says he has more. Here's the info, if you'all are interested:

eBay - New & used electronics, cars, apparel, collectibles, sporting goods & more at low prices

...and no--the seller isn't my brother or uncle, or cousin......

wow. it looks like massive heatsinks. do you have the dimensions?

EDIT: never mind. i found it. 0,74. maybe. it depends onon the temp of the heatsink. you want 25celsius above ambient?
3pr channal will do it

CanAm Man · 17th September 2011, 02:33 AM

From the eBay seller:

I do have many other lengths (up to 6ft) so if you tell me the aproximate size your looking for I can see what I currently have available. If you'd like an exact length I can accomodete that as well but there is a cutting fee that would have to be covered. It's a fee that I have to pay and I'd just pass that amount along. I have several already cut, exactly like you received except for the length, in the 4", 6", 7" and 11" ranges. I'd be happy to give you a good deal on any of them. I also have many other profiles (shapes) in stock so if there is a preference for shorter or wider or whatever; let me know and I can send you a drawing of the closest match. Regarding the power rating, the 0.74 C/W rating was my personal testing. The industry standard for that part is closer to 0.7 C/W.

-------------- I've asked the eBay seller for his "non-eBay" Email address; when I get it, I'll post it for you'all, in case you want further communication with this seller.

CanAm Man · 17th September 2011, 02:35 AM

AudioSan, and all......

The dimensions on these specific heatsinks are a 3-3/8" x 5" base, with fins rising 5-3/8" from the milled surface of the base. These are my actual measurements of my samples.

CanAm Man · 17th September 2011, 06:24 PM

Jeff, at Machtron. See specifics at the Machtron website.

Seems like a good guy to deal with....... other heatsink options, designs, lengths available from him.

Ken

16th September 2011, 04:50 AM	#2
Zen Mod diyAudio Member Join Date: Jan 2003 Location: ancient Batsch , behind Iron Curtain	pair for one F5 channel , with plenty of bottom clearance __________________ my Papa is smarter than your Nelson ! tnx to clean thread ; Cook Book ; PSM LS Cook Book ; Baby Diyaudio FORUM ; BAF Forum & Gallery;I'm dumb

17th September 2011, 02:33 AM	#8
CanAm Man diyAudio Member Join Date: Sep 2006 Location: Colorado Springs, CO	More info on these heatsinks From the eBay seller: I do have many other lengths (up to 6ft) so if you tell me the aproximate size your looking for I can see what I currently have available. If you'd like an exact length I can accomodete that as well but there is a cutting fee that would have to be covered. It's a fee that I have to pay and I'd just pass that amount along. I have several already cut, exactly like you received except for the length, in the 4", 6", 7" and 11" ranges. I'd be happy to give you a good deal on any of them. I also have many other profiles (shapes) in stock so if there is a preference for shorter or wider or whatever; let me know and I can send you a drawing of the closest match. Regarding the power rating, the 0.74 C/W rating was my personal testing. The industry standard for that part is closer to 0.7 C/W. -------------- I've asked the eBay seller for his "non-eBay" Email address; when I get it, I'll post it for you'all, in case you want further communication with this seller.

17th September 2011, 06:24 PM	#10
CanAm Man diyAudio Member Join Date: Sep 2006 Location: Colorado Springs, CO	Contact info Jeff, at Machtron. See specifics at the Machtron website. Seems like a good guy to deal with....... other heatsink options, designs, lengths available from him. Ken

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Open baffle candidate???	sandyhooker	Full Range	6	25th June 2009 09:11 PM
ab class heatsink dimensioning	morpheus82	Solid State	6	21st April 2005 09:35 PM
N.E.W A-60 Class A heatsink	vsr123	Pass Labs	10	19th May 2004 07:45 PM
Is an AD8066 would be a good candidate for Class A biasing ?	dtm1962	Digital Source	0	3rd May 2004 10:03 PM


	Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving

16th September 2011, 05:03 AM	#3
wrenchone diyAudio Member Join Date: Feb 2004 Location: Silicon Valley	Bottom clearance - no saggy bottoms around here.. A breath of air from a slow fan might make those heat sinks very A-worthy.

16th September 2011, 11:31 AM	#5
buzzforb diyAudio Member Join Date: Oct 2010 Location: Burlington, NC	I think someone sold you a polished engine block.

17th September 2011, 02:35 AM	#9
CanAm Man diyAudio Member Join Date: Sep 2006 Location: Colorado Springs, CO	AudioSan, and all...... The dimensions on these specific heatsinks are a 3-3/8" x 5" base, with fins rising 5-3/8" from the milled surface of the base. These are my actual measurements of my samples.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read