Forte 1a left channel buzz - 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 9th March 2013, 10:57 PM   #1
diyAudio Member
 
Join Date: Mar 2013
Location: Pottstown
Default Forte 1a left channel buzz

I have used my Forte 1a for at least twenty years now, and it has been exemplary. Recently it developed a buzz in the left channel that begins after about two minutes of warmup, and doesn't go away thereafter. I have another amp in the system, and all is well, but I'd love to be able to repair the Forte!

Thanks!
Les
  Reply With Quote
Old 10th March 2013, 01:07 AM   #2
Zen Mod is offline Zen Mod  Serbia
diyAudio Member
 
Zen Mod's Avatar
 
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
and , the question is ?

__________________
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 10th March 2013, 04:33 PM   #3
diyAudio Member
 
Join Date: Mar 2013
Location: Pottstown
What would be the basic diagnostic procedure to determine the cause of the buzz?
  Reply With Quote
Old 10th March 2013, 04:42 PM   #4
diyAudio Member
 
jacco vermeulen's Avatar
 
Join Date: Oct 2004
Location: At the sea front, Rotterdam or Curaçao
Send a message via Yahoo to jacco vermeulen
Lytic can oil-exchange.
__________________
The buck stops Here
  Reply With Quote
Old 10th March 2013, 07:48 PM   #5
Zen Mod is offline Zen Mod  Serbia
diyAudio Member
 
Zen Mod's Avatar
 
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
or just oil-in-can exchange ?

__________________
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 10th March 2013, 10:35 PM   #6
diyAudio Member
 
Andersonix's Avatar
 
Join Date: Jan 2004
Location: Silicon Valley
If it's a weak PS cap and a single PS for a stereo amp, why is only one channel buzzing?
  Reply With Quote
Old 10th March 2013, 10:37 PM   #7
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 time for overall electrolytic caps change

you're having some caps on pcbs , too
__________________
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 10th March 2013, 11:00 PM   #8
diyAudio Member
 
jacco vermeulen's Avatar
 
Join Date: Oct 2004
Location: At the sea front, Rotterdam or Curaçao
Send a message via Yahoo to jacco vermeulen
Quote:
Originally Posted by Andersonix View Post
buzzing?
The Model 1A doesn't have a single PS, has a bridge rectifier and two cans for each channel.

(Model 3 has a "single" PS, power supply of the 1A, but piggy-back cans)

Papa no need no helper slaves, only small foilies and a stnkg big SideReal.
__________________
The buck stops Here

Last edited by jacco vermeulen; 10th March 2013 at 11:06 PM.
  Reply With Quote
Old 10th March 2013, 11:26 PM   #9
diyAudio Member
 
Join Date: Mar 2013
Location: Pottstown
So the first thing to try is the electrolytics? I assume original replacements are unavailable, but are there good current options?
  Reply With Quote
Old 10th March 2013, 11:31 PM   #10
Zen Mod is offline Zen Mod  Serbia
diyAudio Member
 
Zen Mod's Avatar
 
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
just to be sure that your specimen is intact ( ref factory ) , it's good to have some pics posted

sorry - I'm thinking better when aided visually



( after dozen of years of constant service , it's not unusual to have dying caps)
__________________
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
Adcom GFA-555 Left Channel Buzz Dudeman258 Pass Labs 18 14th March 2013 02:25 PM
Forte 1a hooch2259 Pass Labs 4 8th February 2013 01:26 AM
Adcom GFA-555 Left Channel Buzz Help Dudeman258 Solid State 0 6th May 2011 09:29 PM
NAD 310 buzz in left channel Rodmunch Solid State 2 22nd March 2009 12:58 AM
Forté 1A - buzz problem!!! lukesound Pass Labs 3 20th February 2009 10:43 AM


New To Site? Need Help?

All times are GMT. The time now is 08:08 PM.


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