4 sk 102 heatsinks. what amp can it be used for?? - diyAudio
Go Back   Home > Forums > Amplifiers > Pass Labs

Pass Labs This forum is dedicated to Pass Labs discussion.

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
Reply
 
Thread Tools Search this Thread
Old 20th November 2004, 01:40 PM   #1
wuffer is offline wuffer  Denmark
diyAudio Member
 
Join Date: Feb 2004
Location: denmark
Default 4 sk 102 heatsinks. what amp can it be used for??

i have 4 SK 102 heatsinks

the height is 100mm

http://www.schuro.de/Daten/Fischer/SK47.pdf

is there any amp i could bould.. i havde the aleph p 1.7 preamp and i was thinking of yet an aleph

can it be done???
  Reply With Quote
Old 20th November 2004, 02:02 PM   #2
Stabist is offline Stabist  Slovenia
diyAudio Member
 
Stabist's Avatar
 
Join Date: Sep 2002
Location: Slovenia
at 100mm height - the factor is 0,4K/W - so I would take 2 and 2 heatsinks per each channel - if you want to stay on the very "safe" side - A3 is the choice - you'll have 20°C rise above ambient temp - with A5 that goes to 30°C ... Still very very OK!

The only thing is that the chassis will be very wide and depth - but quite low ... But personnaly - I like that ...
  Reply With Quote
Old 20th November 2004, 02:12 PM   #3
wuffer is offline wuffer  Denmark
diyAudio Member
 
Join Date: Feb 2004
Location: denmark
thats nice.. i would look at the a5...
  Reply With Quote
Old 21st November 2004, 09:53 PM   #4
uli is offline uli  Austria
diyAudio Member
 
Join Date: Dec 2002
Location: Vienna, Austria
Default caution

if you mount 2 of these heatsinks in close proximity and thermally coupled (like making an amp side of 430mm length) the thermal resistance is not reduced in a linear manner. this means that you won´t achieve 0.2 K/W in this case, but rather 0.27 K/W - 0.3 K/W because the 2 heatsinks heat each other.

Uli

__________________

'Jazz is not dead, it just smells funny' F.Zappa
  Reply With Quote
Old 22nd November 2004, 06:03 AM   #5
wuffer is offline wuffer  Denmark
diyAudio Member
 
Join Date: Feb 2004
Location: denmark
thats not good.. right??

what is the best way to do it if i should use thise heatsinks???
  Reply With Quote
Old 22nd November 2004, 06:07 AM   #6
uli is offline uli  Austria
diyAudio Member
 
Join Date: Dec 2002
Location: Vienna, Austria
Default aleph design

put the heatsinks on 4 sides, or build an Aleph 3 - you will be on the safe side(25-30° above ambient temperature)

Uli

__________________

'Jazz is not dead, it just smells funny' F.Zappa
  Reply With Quote
Old 22nd November 2004, 06:13 AM   #7
wuffer is offline wuffer  Denmark
diyAudio Member
 
Join Date: Feb 2004
Location: denmark
what if i make 2 mono blocks??? strange looking amp then i guess..
  Reply With Quote
Old 22nd November 2004, 06:18 AM   #8
uli is offline uli  Austria
diyAudio Member
 
Join Date: Dec 2002
Location: Vienna, Austria
Default that would be fine!

Uli

__________________

'Jazz is not dead, it just smells funny' F.Zappa
  Reply With Quote
Old 22nd November 2004, 06:20 AM   #9
wuffer is offline wuffer  Denmark
diyAudio Member
 
Join Date: Feb 2004
Location: denmark
then i would go to the drawing board...

tanks
  Reply With Quote
Old 22nd November 2004, 06:42 AM   #10
diyAudio Member
 
jacco vermeulen's Avatar
 
Join Date: Oct 2004
Location: At the sea front, Rotterdam or Curaçao
Send a message via Yahoo to jacco vermeulen
Default Re: caution

Quote:
Originally posted by uli
if you mount 2 of these heatsinks in close proximity and thermally coupled (like making an amp side of 430mm length) the thermal resistance is not reduced in a linear manner. this means that you won´t achieve 0.2 K/W in this case, but rather 0.27 K/W - 0.3 K/W because the 2 heatsinks heat each other.
If you look at the graph for this sinkprofile your story is correct if both heatsinks are placed on top of eachother, that's when 0.27 to 0.30 applies.
Heatsinks act like chimneys, place two next to eachother and each retains its function.
More important with Class A amplifiers is to put the heatsinks well above floorlevel so that cool air may flow to the bottom of the heatsink, warm and rise.
If placed parallel to eachother there is the effect of cross influence but with minimal effect.
Put a vertical plate to the open flange side of the heatsink and the thermal factor would be reduced to a significantly lower level than 0.20 at 100 mill (creating a true chimney).
A heatsink like that is extremely costly in production, therefore only done on special order.
Some manufacturers get around that problem by placing the heatsink in a duct, for example take a look at the Vincent SP991.

An idea for the true DIY'r, build a heatsink from 1/2 inch thick alloy plates, tapped and bolted together, with thermal grease at the joints. A heatsink shaped to favor, with excellent cooling ability, and a base plate of more favorable thickness for cooling high bias demands than regular alloy heatsinks.
The really cheeky use copper plates.
__________________
No More Mr Nice Guy
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
To-3 Heatsinks sandstorm33 Swap Meet 8 6th February 2008 04:33 PM
about heatsinks bigpanda Solid State 2 4th May 2005 03:34 PM
Heatsinks DD_Davo Chip Amps 2 13th April 2005 01:00 PM
Heatsinks Peter Daniel Swap Meet 19 3rd February 2004 11:08 PM
Heatsinks for DoZ ultrachrome Solid State 0 4th February 2003 09:23 PM


New To Site? Need Help?

All times are GMT. The time now is 08:53 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright ©1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2