Aleph 5 (4 x IRFP240 per channel) - 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 21st May 2008, 05:37 PM   #1
peter7 is offline peter7  Hong Kong
diyAudio Member
 
Join Date: Apr 2005
Location: hong kong
Default Aleph 5 (4 x IRFP240 per channel)

Hello, I want to build Aleph 5 have 4 x IRFP240 per 1 channel (original is 6 x IRFP240), is it possible? is it need to change some?
  Reply With Quote
Old 22nd May 2008, 01:59 AM   #2
Stones is offline Stones  United States
diyAudio Member
 
Stones's Avatar
 
Join Date: Jan 2004
Location: MN
ok you have had 61 reads and no response, this happens when you ask a question that a little searching will answer.

The original Aleph 5 had 6 fets, if you lower this to 4 with no other changes you will have one third less current available.
You can find an excel sheet done by wuffwaff that will help you calculate the effects.

I don't feel like you know what voltage or current you need so I can't concisely help you.
  Reply With Quote
Old 22nd May 2008, 05:29 PM   #3
peter7 is offline peter7  Hong Kong
diyAudio Member
 
Join Date: Apr 2005
Location: hong kong
Hello Stones, thanks for your reply, I use +- 35VDC which is original circuit ,some people told me just change the R64-66 & R40-42 from 1 ohm to 0.7 ohm for 4 fets ,is it correct??
  Reply With Quote
Old 23rd May 2008, 12:01 AM   #4
Stones is offline Stones  United States
diyAudio Member
 
Stones's Avatar
 
Join Date: Jan 2004
Location: MN
There are other ways to change the current but it sounds about right, you know the fets will run hotter than god intended in the original design. Would it not be better to build it with lower rails (Aleph 3, or better yet build the AlephJ) what load are you running into?
  Reply With Quote
Old 26th May 2008, 06:32 PM   #5
karajak is offline karajak  Greece
diyAudio Member
 
Join Date: Jan 2008
Location: ATHENS
hi ! i want to use 8 240s instead of 6 for aleph5 with 31,5 V. The use of 1,5ohm resistors is the action correct?
  Reply With Quote
Old 26th May 2008, 06:54 PM   #6
Blues is offline Blues  United States
Lightning In A Bottle
diyAudio Member
 
Blues's Avatar
 
Join Date: Sep 2003
Location: The Milky Way
With lower supply voltages and more output devices you can keep 1R power resistors for a better performance in low impedance loads. 2A total bias.
__________________
Life simplified! Leap into the Warpspeed wormhole... http://www.6moons.com/audioreviews/warpspeed/1.html
  Reply With Quote
Old 26th May 2008, 07:30 PM   #7
karajak is offline karajak  Greece
diyAudio Member
 
Join Date: Jan 2008
Location: ATHENS
thanks for the reply.i will keep the 1om resistors.i wonder if this way the temperature per fet is lower?
  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
Aleph 5: IRFP240 vs IRFP240A or ??? RussB Pass Labs 0 9th October 2006 05:57 PM
Matced IRFP240`s & Aleph-x rev 1.0 PCBs skaara Swap Meet 12 21st August 2006 05:22 PM
SFH9240 instead IRFP240-aleph-x freakyone Pass Labs 10 30th June 2006 02:14 AM
matched irfp240 aleph 2 MikeZ Pass Labs 0 17th January 2003 08:42 PM


New To Site? Need Help?

All times are GMT. The time now is 03:42 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