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 January 2007, 10:53 PM   #141
flg is offline flg  United States
diyAudio Member
 
flg's Avatar
 
Join Date: Jul 2005
Location: North East
I agree, the McMillans nay not be the culpret, but their solder joint could be? It seems it's a component that destroys cmrr???
  Reply With Quote
Old 22nd January 2007, 04:49 AM   #142
diyAudio Member
 
Join Date: Apr 2005
Location: Switzerland
Quote:
Originally posted by flg
I don't see the McMillan R's in that schemo???
2.2K would possibly be the value??? Post #134???

But, then again, those R19-29 guy's???
You aren't running a single ended input are you???
McMillans are installed, so the schematic is slightly different from the original circuit I showed in previous post. First, I resoldered the parts around the CCS but this did not solve the problem. Next, I'll try installing C102 C105. I will post the results later.
  Reply With Quote
Old 22nd January 2007, 04:02 PM   #143
diyAudio Member
 
wuffwaff's Avatar
 
Join Date: Aug 2001
Location: Ingolstadt Germany
Hi,

yes C102 is the one I meant. Donīt forget there are two of them......
Start with something small like 1n or 1n5.

William
__________________
een ooievaar is geen konijn want zijn oren zijn te klein!
  Reply With Quote
Old 22nd January 2007, 08:11 PM   #144
diyAudio Member
 
Join Date: Apr 2005
Location: Switzerland
Quote:
Originally posted by wuffwaff
Hi,
yes C102 is the one I meant. Donīt forget there are two of them......
Start with something small like 1n or 1n5.

William
Here comes a short update of my ongoing chase for the hum in my aleph-x:

1) I inserted C102 and C105 as recommended, but used 10nF instead of the recommended 1nf, since 10nF was the smallest value I had on hand-> no change, same amount of hum

2) Replaced Q3& Q4-> no change, same amount of hum

3) Resoldered all small components around Q3-> around 40% reduction in hum judged by measuring output with scope, amplitude of oscillation is now around 10mV

I also noticed that hum level goes down as amplifier warms up.
Good news is I REALLY like the sound of my aleph-xs the longer I am listening!
  Reply With Quote
Old 22nd January 2007, 08:19 PM   #145
diyAudio Member
 
wuffwaff's Avatar
 
Join Date: Aug 2001
Location: Ingolstadt Germany
Hi,

thatīs good news. So I would clean the circuit board and do some more soldering, then clean it again.

William

P.S. donīt forget to remove the caps if they are not necessary!
__________________
een ooievaar is geen konijn want zijn oren zijn te klein!
  Reply With Quote
Old 6th February 2007, 06:27 PM   #146
diyAudio Member
 
Join Date: Apr 2005
Location: Switzerland
Default brif update on my chase of the hum

Hi All,

in my attempts to chase the hum out of one of my monoblocks I think I solved the problem- kind of.
After all my fruitless attempts I finally turned my attention to the input section and I exchanged the LTPs (Q5&Q7). The result is a reduction of the hum to a very low level. On my 96 db efficient speakers you can only hear it within 1m from the speaker. Funny thing is when I look at the output with my scope, I now see almost the identical amount of hum on both sides, i.e. the - side that had before been absolutley silent now has the same amount of noise as the + side. (both sides now look like the lower trace in the picture of my post #123). I guess the result is that the X-configuration now rejects the common noise quite efficiently....
  Reply With Quote
Old 30th August 2008, 04:24 AM   #147
lineup is offline lineup  Sweden
diyAudio Member
 
lineup's Avatar
 
Join Date: Dec 2005
Location: the north
Quote:
Originally posted by Zen Mod
locall time - 2320
this is Zen :
(again-be happy ,all of you )
how cute, Zen Mod
looks like a father and child image
http://www.diyaudio.com/forums/attac...amp=1167603488
__________________
lineup
  Reply With Quote
Old 3rd September 2008, 03:41 AM   #148
jpc6204 is offline jpc6204  United States
diyAudio Member
 
Join Date: Sep 2007
The beauty of symmetry!
  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
AX100 100W Aleph-X Monoblocks gl Pass Labs 635 23rd October 2012 05:25 PM
FS/FT: Fully Built Aleph-X Monoblocks [AUS] kenny12 Swap Meet 14 18th May 2009 11:03 AM
Aleph 3 monoblocks for sale cowanrg Swap Meet 4 17th April 2007 04:37 AM
6 monoblocks finished Cro maniac Chip Amps 17 14th January 2006 07:50 PM


New To Site? Need Help?

All times are GMT. The time now is 03:13 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright Đ1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2