FET10e Channel Noise - 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 12th October 2010, 06:03 PM   #1
diyAudio Member
 
Join Date: Oct 2010
Cool FET10e Channel Noise

Hello all! New user looking for assistance troubleshooting a fet10e. Recently right channel began "making noise". Narrowed down with O-scope to sinusiodal inputs resulting in 1/2 wave rectified output. Further checking, it appears the output transistors Q8, Q9 are not biased on (comp1 voltage is ~0.4v, while on good channel it is around 0.88v). I suspect component hfe drift, possbily requiring adjustment of pot or component replacement.

Anyone have any suggestions? Thx.
  Reply With Quote
Old 12th October 2010, 07:54 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
Q8 and Q9 ?

on which schematic ?

this one ?
Attached Images
File Type: jpg 1.jpg (68.4 KB, 78 views)
__________________
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 12th October 2010, 11:23 PM   #3
diyAudio Member
 
Join Date: Oct 2010
Default FET10e Channel Noise

Yes, thats the one! S5541098.
  Reply With Quote
Old 12th October 2010, 11:48 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
can you use that pic and write measured voltages in few critical places

the more the merrier
__________________
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 14th October 2010, 12:32 AM   #5
diyAudio Member
 
Join Date: Oct 2010
Default Troubleshoot FET10e

OK, much easier for me to make a little spreadsheet. See if you see what I am thinking - Q7...
Attached Files
File Type: txt Voltagestxt.txt (1.0 KB, 20 views)
  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
Noise on R-channel NAD C370 sandeman Solid State 4 25th July 2008 04:32 PM
Right Channel Noise cwoodall Solid State 4 29th June 2006 07:25 PM
TDA1541 - noise in one channel? phofman Digital Source 4 1st April 2006 08:34 AM
Noise in one channel of Ono Netlist Pass Labs 6 6th March 2006 03:19 PM
strange noise from right channel keyser Everything Else 15 2nd May 2005 11:14 PM


New To Site? Need Help?

All times are GMT. The time now is 02:06 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