A little help needed with a Pass Aleph 30 - 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 8th May 2010, 05:17 PM   #1
diyAudio Member
 
Join Date: Aug 2008
Default A little help needed with a Pass Aleph 30

Hello,

A couple of days ago I decided to repair a loose RCA jack on my factory Pass Aleph 30 amp. I opened up the top, tightened down the set nut on the inside and relieve a few of the extra turns it had over the years. While inside I gave it a light dusting.

Put it together, fired it up and it sounded great until it reached full temp. In the left channel only (the side with the loose RCA) during high dynamic passages it started to distort, making a crackling sound and the volume started to fade in and out only in that channel and only at full temp. I shut it down, and the next morning did a thorough cleaning with a tooth brush and 99% isopropyl alcohol as the boards were pretty dirty still. Let it dry out over night, put it back in the system and tried it again. Same problem at full temp only. Switched left and right channel inputs to see if it was in the source or preamp. Still in the left channel only and still only at full temp (after 30 mintues or so, hot to touch, canít hold the heat sinks more than a couple of seconds). Additionally, when shutting down the amp, during the usual low thump when the speaker cone moves out a little, there is crackling distortion in the left channel only.

Iím wondering if the RCA jack could cause this? If so, I can remove the heat shrink and check the solder connections at the jack. I could also just replace the jack while it is open. Or, did I cause another problem when I was cleaning?

Thank you in advance.

Aaron
  Reply With Quote
Old 8th May 2010, 06:12 PM   #2
Zen Mod is offline Zen Mod  Serbia
diyAudio Member
 
Zen Mod's Avatar
 
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
it's really hard to say without exact insight in amp .

can be many things - loose solder contact , or even worn cap , finished with slight touch .

anyway - it probably needs some thorough care , after all these years ;

maybe few small electrolytics on pcbs are most suspicious

can you make any good photo of inside ?
__________________
my Papa is smarter than your Nelson !
clean thread; Cook Book;PSM LS Cook Book;Baby DiyA ;Mighty ZM's Bloggg;Papatreasure;Papa...© by Mighty ZM
  Reply With Quote
Old 8th May 2010, 06:18 PM   #3
diyAudio Member
 
Join Date: Aug 2008
I can post a couple of pics tomorrow. The boards are good and clean on the tops at least. There are a few small lytic caps on the boards and I may have moved them a little in cleaning.. Hmmmm.....

Maybe it's time to send it off for a tune up...
  Reply With Quote
Old 8th May 2010, 06:40 PM   #4
Zen Mod is offline Zen Mod  Serbia
diyAudio Member
 
Zen Mod's Avatar
 
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
if you aren't even remotely sure in what you're doing , it's better to send them to someone who is ;
this amp deserve good care and love ..... it's just like your dearest ugly dog
__________________
my Papa is smarter than your Nelson !
clean thread; Cook Book;PSM LS Cook Book;Baby DiyA ;Mighty ZM's Bloggg;Papatreasure;Papa...© by Mighty ZM
  Reply With Quote
Old 8th May 2010, 06:44 PM   #5
diyAudio Member
 
Join Date: Aug 2008
Well said. I emailed Wayne and the guys at Pass Labs. I don't want to cause more harm than good. I know just enough to be dangerous!
  Reply With Quote
Old 8th May 2010, 06:57 PM   #6
Zen Mod is offline Zen Mod  Serbia
diyAudio Member
 
Zen Mod's Avatar
 
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
Quote:
Originally Posted by johnsonad View Post
.....I emailed Wayne and the guys at Pass Labs.......
who they are ?




put a note on top cover - "ZM sez that's my ugliest dog! " and they will charge you a double

__________________
my Papa is smarter than your Nelson !
clean thread; Cook Book;PSM LS Cook Book;Baby DiyA ;Mighty ZM's Bloggg;Papatreasure;Papa...© by Mighty ZM
  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
Best Pass Design Zen, SOZ, Aleph 30?? mozfet Pass Labs 16 11th June 2013 07:31 PM
Needed: Toroid To Complete Aleph 30 Mark Allen Swap Meet 5 26th January 2010 10:17 PM
Pass aleph 30 clone for sale hc167 Swap Meet 0 27th July 2008 01:10 AM
16 Ohm speakers with Pass Aleph 3/30? ccvogel Pass Labs 1 7th April 2006 05:21 AM
Upgrading the by-pass Caps for Aleph 30 Jozua Pass Labs 3 22nd December 2003 02:19 PM


New To Site? Need Help?

All times are GMT. The time now is 12:53 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