Substitution MOS for Aleph 3 - 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 18th September 2001, 10:06 PM   #1
diyAudio Member
 
Miles Teg's Avatar
 
Join Date: Aug 2001
Location: Rouen, France
What is in objective order, the best choice for the MOSFET in the schematics of the Aleph 3.
Can we find easily the IRF244 or can we purchase another reference ?
__________________
AV: Kali 3 | Centre: Socoa MT30 | Surround: Antigua MT360 | Sub: Triangle Meteor 0.1.5
PS3 | PC | Philips CD723 | Denon AVR-1910 | Projecteur: Epson TW3600
  Reply With Quote
Old 18th September 2001, 10:10 PM   #2
Freddie is offline Freddie  Sweden
diyAudio Member
 
Join Date: Oct 2000
Location: Sweden
Default IRFP240

I will use IRFP240.
  Reply With Quote
Old 18th September 2001, 10:19 PM   #3
diyAudio Member
 
Miles Teg's Avatar
 
Join Date: Aug 2001
Location: Rouen, France
Thanks, in this what is the best way to cool it ? 1 or more heatsink ? The value of heatsink ? The use of fan ? I'm not interested by water cooled.
__________________
AV: Kali 3 | Centre: Socoa MT30 | Surround: Antigua MT360 | Sub: Triangle Meteor 0.1.5
PS3 | PC | Philips CD723 | Denon AVR-1910 | Projecteur: Epson TW3600
  Reply With Quote
Old 18th September 2001, 10:27 PM   #4
Freddie is offline Freddie  Sweden
diyAudio Member
 
Join Date: Oct 2000
Location: Sweden
Default Big heatsink...

Use a big heatsink. I don't like fans (they are noisy).
But feel free to use a fan if you want :-)

The heatsink should be rated at 0,25K or less /channel.
I think the Aleph 3 dissipates around 100W / channel, so the heatsink will operate at 25 degrees C. above ambient (0,25 * 100) if you are using a 0,25K heatsink.

/Freddie

[Edited by Freddie on 09-18-2001 at 05:30 PM]
  Reply With Quote
Old 18th September 2001, 10:34 PM   #5
diyAudio Member
 
Miles Teg's Avatar
 
Join Date: Aug 2001
Location: Rouen, France
0.25 °C/W it's very very big (and expensive). Can we take separate heatsink ? They will may be more little and more accessible?
__________________
AV: Kali 3 | Centre: Socoa MT30 | Surround: Antigua MT360 | Sub: Triangle Meteor 0.1.5
PS3 | PC | Philips CD723 | Denon AVR-1910 | Projecteur: Epson TW3600
  Reply With Quote
Old 19th September 2001, 04:03 AM   #6
diyAudio Member
 
Join Date: Sep 2001
Location: Salt Lake City
Fans are ok if mounted correctly(isolated) and not driven to an audible speed. Use a 12 volt dc 4" diameter 5 blade fan and run it at about 6 to 7 volts and it won't be heard till you have your ear right on top of it. It does not take a trillion cfm to keep things cool, just some slight air motion in general to get the heatn away. There are also "Smart" fans that have built in thermostats and will automatically sense the temperature and adjust speed accordingly. In this case the heat is a pretty constant thing though and the smart part can be left out.

Mark Gulbrandsen
Salt Lake City, UT
  Reply With Quote
Old 19th September 2001, 04:08 AM   #7
Super is offline Super  United States
diyAudio Member
 
Join Date: May 2001
Location: Connecticut
Send a message via AIM to Super
A high quality computer fan should do the trick. Some of the inexpensive ones have poor quality bearings. Often they'll be audible, and over time they may begin to squeak and eventually lock up. Every once in a while, I like to blow them out using a can of compressed air, and if you can access the bearing, I add a lube designed for delicate parts. Keeping it free of dust will keep it quiet and make the bearings last a lot longer.
__________________
Bryan
  Reply With Quote
Old 19th September 2001, 04:59 PM   #8
diyAudio Member
 
Join Date: Aug 2001
Miles,
Consider using smaller heatsinks, ( 1 per device, of suitable ratings of course ) and mount them to larger chunks of aluminium to add to the heat dissipation. I've tried it and it works just fine.

cp642







  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
Hitachi FET Substitution poor_lackey Solid State 20 12th March 2011 01:15 AM
4E27 as a substitution of 845 ja2dhc Tubes / Valves 0 2nd September 2008 02:12 AM
6N1/6N3 substitution woodturner-fran Tubes / Valves 7 31st January 2007 01:15 PM
Red LED substitution questions sunrise Tubes / Valves 16 12th April 2006 11:54 AM
Aleph-x part substitution GlouBou Pass Labs 2 29th August 2004 09:16 AM


New To Site? Need Help?

All times are GMT. The time now is 07:09 AM.


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