F5 power amplifier - Page 767 - 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 4th April 2010, 06:55 PM   #7661
Renron is offline Renron  United States
diyAudio Member
 
Renron's Avatar
 
Join Date: Jan 2007
Location: Sacramento
Just to be clear on this. No one is suggesting using A/S without an insulator like mica or a Silpad.

Yep, very thin layer. We use a razor blade to scrape (gently) off the excess, it's only to fill in the micro pores of the heatsink / heat generating device.

Ron
__________________
"If it doesn't work properly, hope it catches on fire"- Nelson Pass @ BA3
"I fired up the prototype. Literally." The Prophet Pass.

Last edited by Renron; 4th April 2010 at 06:58 PM.
  Reply With Quote
Old 4th April 2010, 07:22 PM   #7662
tinitus is offline tinitus  Europe
diyAudio Moderator R.I.P.
 
Join Date: Nov 2005
Quote:

Straight rip from A/S website:

............While it is not electrically conductive, the compound is very slightly capacitive and could potentially cause problems if it bridges two close-proximity electrical paths.)
Being capacitive means its conductive at very high frequency, no?
__________________
sometimes we know very little, and sometimes we know too much
  Reply With Quote
Old 4th April 2010, 08:43 PM   #7663
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
Quote:
Originally Posted by tinitus View Post
Being capacitive means its conductive at very high frequency, no?
no, it may act as a dielectric and factor up the capacitance between two adjacent conductors.

I am not trying to keep this argument going, but I believe the point is some of these silvery looking pastes are electrically conductive and some are not.
How can we tell them apart?

I think it's far simpler and easier to avoid the silvery type where electrical conductivity will cause a problem.
__________________
regards Andrew T.
  Reply With Quote
Old 4th April 2010, 10:46 PM   #7664
Renron is offline Renron  United States
diyAudio Member
 
Renron's Avatar
 
Join Date: Jan 2007
Location: Sacramento
Quote:
Originally Posted by AndrewT View Post
no, it may act as a dielectric and factor up the capacitance between two adjacent conductors.

I am not trying to keep this argument going, but I believe the point is some of these silvery looking pastes are electrically conductive and some are not.
How can we tell them apart?

I think it's far simpler and easier to avoid the silvery type where electrical conductivity will cause a problem.
Andrew T,
I couldn't agree more.
I have NOT used it on my F5, I was just trying to find out the "source" of the earlier comments against using it. As it has performed flawlessly for 100s of CPUs. (personally)

Tinitus,
"Being capacitive means its conductive at very high frequency, no? "

that's way beyond my expertise............If I had any.

Ron
__________________
"If it doesn't work properly, hope it catches on fire"- Nelson Pass @ BA3
"I fired up the prototype. Literally." The Prophet Pass.
  Reply With Quote
Old 4th April 2010, 10:59 PM   #7665
tinitus is offline tinitus  Europe
diyAudio Moderator R.I.P.
 
Join Date: Nov 2005
Quote:
Originally Posted by Renron View Post

it has performed flawlessly for 100s of CPUs. (personally)

Ron
Ah, I see now
I think a CPU chip is a different matter, and arctic silver compound may be just perfect there
But its a different construction

With output devices you cannot be 100% certain that the compound wont "connect" with the mounting bolt/screw
__________________
sometimes we know very little, and sometimes we know too much
  Reply With Quote
Old 4th April 2010, 11:31 PM   #7666
diyAudio Member
 
Join Date: Jan 2004
Location: Michigan
Default My conversation with the folks from Arctic Silver.

I wrote:

I have a need to use a thermal compound with mica insulators between the transistors and the heatsink. Would Arctic Silver 5 be a good product to use?
Regards,
Paul Blossom

Their reply:

Hi Paul,

We recommend Ceramique for your application.
Long term stability should be good.

Best Regards,

Kirk

Arctic Silver Incorporated - Home
__________________
The human capacity for self delusion is nearly infinite.
  Reply With Quote
Old 5th April 2010, 01:07 AM   #7667
diyAudio Member
 
Join Date: Mar 2010
CPUs are electrically insulated whithin their case and the silver (which we all know is a very good conductor of electricity) is also a very good conductor of heat and is used for this purpose. The same company, Arctic Silver, also makes a thermal greese without silver for power mosfets and other electrically sensitive computer components. It is advised to use the proper compound for its designed application or you risk serious problems. It may be safe when used carefully, it may blow your amp if it creates an electrical short. Doesn't make since to risk your amp over a couple dollars worth of thermal greese. My 5 cents worth...inflation ya know



Tony
  Reply With Quote
Old 5th April 2010, 01:47 AM   #7668
labjr is offline labjr  United States
diyAudio Member
 
Join Date: Apr 2003
Location: MA
I use Ceramique for CPUs because it's a little thicker than traditional grease, so the heatsink won't slide around. However, I still use Thermalcote for almost everything else. Works fine for me. It costs less and is rated at higher temperature than all the Arctic Silver products. I think Nelson uses Thermalcote. So I'm guessing it's probably not necessary to use a boutique product for this particular application.
  Reply With Quote
Old 5th April 2010, 02:06 AM   #7669
The one and only
 
Nelson Pass's Avatar
 
Join Date: Mar 2001
I use Thermalcote for the usual reason - I have a large case of
it. The heat sinks on FW products are bead blasted, and the
result is that the surface is not smooth enough for really good
heat conduction without grease.

Another interesting factoid, the Drain of the Jfet in the F3 does
not use an insulating pad - the part is insulated by the grease
and the anodizing.

  Reply With Quote
Old 5th April 2010, 02:33 AM   #7670
diyAudio Member
 
acold7dusta's Avatar
 
Join Date: Sep 2009
Location: Buffalo, NY
Quote:
Originally Posted by Renron View Post
Just to be clear on this. No one is suggesting using A/S without an insulator like mica or a Silpad.

Yep, very thin layer. We use a razor blade to scrape (gently) off the excess, it's only to fill in the micro pores of the heatsink / heat generating device.

Ron
otherwise you get a direct short from drain to ground, like me

(measured and confirmed all your suspicions)
__________________
Squeezebox Touch>Coax>MH Dac 25.2>Marantz PM-15S1>Seas Thor (Small)/Beyerdynamic DT770

Last edited by acold7dusta; 5th April 2010 at 02:35 AM.
  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
Rockford Fosgate Power 20001 bd amplifier power rating?? pachoorion Car Audio 8 8th May 2011 10:49 PM
Power transformers versus amplifier output power..what is your option? destroyer X Solid State 38 9th May 2009 05:23 PM
McIntosh Power Amplifier Power Guard johnnyrt Solid State 2 23rd August 2007 10:22 PM
Output power for a power amplifier Progg70 Solid State 33 10th September 2006 08:44 AM
Amplifier 3000 Wats Rms Power + Smps Higcht Power Bestiality MARAVILLASAUDIO Class D 1 5th November 2004 04:06 PM


New To Site? Need Help?

All times are GMT. The time now is 04:00 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