Relayed Help on Aleph4 - diyAudio
Go Back   Home > Forums > Amplifiers > Pass Labs
Home Forums Rules Articles diyAudio Store Gallery Wiki Blogs Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

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
Thread Tools Search this Thread
Old 12th October 2001, 11:46 PM   #1
diyAudio Member
mefinnis's Avatar
Join Date: Feb 2001
Location: Adelaide, Australia
Hi All,

For some strange reason I get a lot of help requests on Aleph amps, most of which I can answer easily ....... however, this one's got me stumped !!

Could one of the EE theory types offer any help?
__________________________________________________ ______
Dear Mark,

I'm building your Aleph4 version and experiencing some problem. All seem to be right but when turn on without load (I try first on speaker and burn it), voltage at output goes about 84V (power supply is +- 42V) and burnsR22 and on FET boards the Mosfets and resistors asociated (.68 e 220 ohms), that relate to the s terminal (not S).

Thanks for advice

__________________________________________________ ______

PS: I have already told him to check that the pin configuration of his FETs matches and that they are installed correctly, can't see how this would occur unless FETs are installed incorrectly ;-)

[Edited by mefinnis on 10-12-2001 at 05:56 PM]
  Reply With Quote
Old 13th October 2001, 01:36 PM   #2
diyAudio Member
promitheus's Avatar
Join Date: Jan 2001
Location: Germany
I think that there could be a mistake with the pin layout. Some fets have different layouts. You should check again your connections, unless you have oscilations going on. I canīt really say anything else from the info you gave. Good luck solving your problem.
  Reply With Quote
Old 14th October 2001, 12:35 PM   #3
diyAudio Member
Join Date: Oct 2001
Location: Brazil

Thanks to promitheus and mefinnis, I really commit a mistake in wiring fet pcb to main pcb (changing "s" by "S"). Then the baby work for about 2 hours (great sound) and stop. I checked and find that same fets are burned, that are wired on "s" terminal on the fet boards.Before this,when I turn on the amp I touched all fets and find that these two fets are working hotters than others. Can be this a problem with pcb layout? I notice that only these fets has your source wired directly to R22. I'm looking in the schematics and I think that all fets must have yours sources (before source resistor)conected together. Am'I wrong? (P.S. fets are IRFP250N,matched at .02V, isn't the best choice but are what I can take in my city in the South of Brazil)
  Reply With Quote


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
Aleph4 vs Aleph5 supernet Pass Labs 14 11th January 2005 05:52 PM
Aleph4 damping factor alanyeoh Pass Labs 1 17th August 2004 10:11 PM
R29 in Aleph4 ja Pass Labs 1 5th May 2003 10:26 PM
Aleph4, caps ? victor Pass Labs 1 4th August 2001 01:45 AM
ALEPH4 - URGENT NOTICE !!!!! mefinnis Pass Labs 20 4th April 2001 11:02 PM

New To Site? Need Help?

All times are GMT. The time now is 08:50 AM.

vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright Đ1999-2017 diyAudio

Content Relevant URLs by vBSEO 3.3.2