Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Pass Labs This forum is dedicated to Pass Labs discussion.

F5 power amplifier
F5 power amplifier
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
Thread Tools Search this Thread
Old 19th January 2011, 01:16 PM   #9981
tinitus is offline tinitus  Europe
diyAudio Moderator R.I.P.
Join Date: Nov 2005
F5 power amplifier
noone yet tried to measure temperature of heat radiation, in millimeters from heatsink ?

Im quite sure that even a few millimeters will make a difference
  Reply With Quote
Old 19th January 2011, 02:16 PM   #9982
Bksabath is offline Bksabath  United Kingdom
Join Date: Dec 2007
Just brilliant bit-by-bit going trough each aspect with fine combed.
Rod site is really good and easy to understand tanks for the find.

Udailey as you posted the data
What is the heat propagation on different metals meaning how easy is for heath to travel across
I think that Cooper is about 2 times as good as aluminium but I may be wrong could you help.

I was looking at mounting options and I am going to try something similar to the picture
Attached Images
File Type: jpg Mosfet testing 001.jpg (589.8 KB, 431 views)
  Reply With Quote
Old 19th January 2011, 02:21 PM   #9983
dazed2 is offline dazed2  Canada
diyAudio Member
Join Date: Jun 2010
Location: Toronto
Originally Posted by AndrewT View Post
I see 0.7C/W for 3" long profile for HeatsinkUSA.
A 12" length should be about half of this, i.e. 0.35C/W

I cannot see any spec for Parmetal.

I expect that HeatsinkUSA can dissipate a lot more heat than ParMetal
The Specs for ParMetal are at the bottom of the page.
When I called them they said that the data there was measured data, not theoretical. The quote it in C/W/inch.

Also if I'm reading Udaily right, I should paint the heatsink with black oil? Wow. I didn't know that. When I called Par-Metal they had the option of anodizing...

Last edited by dazed2; 19th January 2011 at 02:23 PM.
  Reply With Quote
Old 19th January 2011, 02:53 PM   #9984
labjr is offline labjr  United States
diyAudio Member
Join Date: Apr 2003
Location: MA
I haven't finished it yet but I bought 2 twelve inch pieces of the Heatsink USA 10 inch profile for my F5. Maybe more than I need. It's pretty hefty stuff at about 12 pounds each. Better too much than not enough. Also looks a bit nicer in person than it does on his website. Made in USA too. Not sure about Par-metal.
  Reply With Quote
Old 19th January 2011, 02:55 PM   #9985
udailey is offline udailey  United States
Passive Aggressive
diyAudio Member
Join Date: Mar 2008
F5 power amplifier
Not black oil but an oil based paint that is black. Well, thats Rod's information.. I just spit it back out here. He says black oil paint very very thin is the best but that anodizing is good to, you can see on his graphs. I would go for the anodizing option but then again you would still be buying a sink that cant compete with HS USA sinks. Honestly in the USA the HS USA guys have the best deal that I can find and the extrusion is made, in my opinion, especially for Pass DIY efforts. Its just my guess but I am betting Russel started his business to take care of us.
Copper spreads the heat the fastest but it doesnt like to LET GO of the heat. Aluminum spreads it pretty fast as well AND dissipates. Aluminum is best in a sink. You want to use a heat spreader? Probably copper is best but I would use some sort of thermal paste to help get the heat from the copper over to the aluminum and you will find folks telling you that copper on top of aluminum causes some sort of chemical reaction and I forget what else happens but two odd metals touching for a long time has some chemical reaction that has been discussed here before. I think if you use the paste you might not worry so much about this reaction.

Edit: Oooooh we are creeping up on 10,000 posts!
purchase LDRs anytime Also try my Resistor Replacers or LDR based Input Selector Email me. diyldr@gmail.com
  Reply With Quote
Old 19th January 2011, 03:10 PM   #9986
osscar is offline osscar  Latvia
diyAudio Member
osscar's Avatar
Join Date: May 2009
Location: Riga, LV
how many F5 are built on these 10 000 posts ?
My DIY so far: two Leach amps, Pass AB100, Pass F5, B1 buffer, Hiraga le monstre, two LM3875, LM1875, OPA549, 6C33C SE, GU32 PP, 6p3c-e PP, Marsh headphone amp.Phono - OBH-8se, Pacific RIAA, inDiscreet Phono, Whammy headphone amp.

Last edited by osscar; 19th January 2011 at 03:12 PM.
  Reply With Quote
Old 19th January 2011, 03:14 PM   #9987
labjr is offline labjr  United States
diyAudio Member
Join Date: Apr 2003
Location: MA
I thought I read that copper is not only a better conductor and for the same reason dissipates heat better. The biggest disadvantage is cost.

Putting the two metals together causes a galvanic reaction which causes corrosion. Sort of like chewing on an aluminum gum wrapper.
  Reply With Quote
Old 19th January 2011, 03:25 PM   #9988
Tripmaster is offline Tripmaster  United Kingdom
diyAudio Member
Tripmaster's Avatar
Join Date: Feb 2008
Location: UK

I built an F5 a while ago using Panasonic TSUP 18000UF caps. I have just spotted what appears to be a good deal and wondered if anyone has used these with their F5

Vishay 15000UF 25V (Part no. MAL205656153E3)

I have attached the data sheet.

[IMG]Click the image to open in full size.[/IMG]
Attached Files
File Type: pdf 15000uf.pdf (140.2 KB, 26 views)
  Reply With Quote
Old 19th January 2011, 03:51 PM   #9989
Bksabath is offline Bksabath  United Kingdom
Join Date: Dec 2007
Tanks udailey

2 different metals in contact chem reaction very good point and need looking at.
Yes heath spreaders it will be.

As 4 ohms speakers loads off currants.

Heath sink I have found this new product in Farnell 1315296
Graphite based so is conductive eletricaly good enoug between sinks and heath spreaders not so on the mosfets.

Thermal conductivity 10.5 W/mK what ever that means.
And red Kerafoll

While here could you help with speakers protection?
To fix a broken amp no problem
to replace speakers money and no music for a while. I could survive that.
To have her say I told you so priceless.
Options are quite a few

Fuses but signall degradation and slow
There is a few around based on low pass filters (nuisance tripping) and there use to be a few dedicated IC now obsollete so ..

I was thinking as AC signall by its nature crosses the zero line voltagge to make a detector that (say ipoteticalicamente Just positive side for semplicity)

Rising edge start a timing circuit when signal return to zero reset the timer

IF there is DC offset or one of the mosfets blow the signal will stay hi and the timer will latch and operate a relay disconecting the speakers same for negative branch.
But relay are not so good with DC as arking between contacts and also compromise signall when connected in series with the speakers
Ten maybe a Mosfet operated as swithc after the capacitors bank when the circuit detect a fault it will stop conducting disconnecting the suply.
Much faster than a relay.

I am stuck with the timing circuit as maybe it need to be 100 or maybe 20 milly seconds
question about mosfet
What is the heat load / disipation for mosfets as switch (saturation region)
I believe it is much less than when in the linear region as in saturation region resistance seen is much lower?

If so It may be possible then to use one as swithc with say full rail voltagge at say 3 / 4
A and use this to disconnect the suply to the amplifier after the capacitor banks.

Help please.
  Reply With Quote
Old 19th January 2011, 04:06 PM   #9990
AndrewT is offline AndrewT  Scotland
Join Date: Jul 2004
Location: Scottish Borders
Originally Posted by dazed2 View Post
The Specs for ParMetal are at the bottom of the page. They quote it in C/W/inch.
that is not Rth s-a.
Rth s-a in C/W is not inversely proportional to the height of the heatsink.
The numbers quoted at the bottom are nonsense.
regards Andrew T.
  Reply With Quote


F5 power amplifierHide 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

Forum Jump

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 05:52 AM.

Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.79%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio