Home OTL Asylum

OTL, Output Transformerless Amplifier User Group.

[ Follow Ups ] [ Post Followup ] Thread: [ Display  All  Email ] [ OTL Asylum ]
[ Alert Moderator ]

RE: Did any of your changes and repairs sort it out? nt

I think yes.
In the course of making repairs after the fuse blew for the second time, which event also took out some of the filter capacitors and some of the current sharing resistors in the power supply output, I substituted carbon comp resistors with metal film resistors. Because the latter are physically larger than the originals, I more conveniently mounted them on the backside of the circuitboard. As it turns out, that was a big no-no, and was causing the noise. Whether it can be called oscillation or just noise I don't know. An EE tells me that it doesn't meet some of the definition of an oscillation, because there are many many mixed frequencies going on at the same time. Anyway, when I remounted those metal film resistors on the other side of the circuitboard, the noise is definitely reduced by at least 90%. I also found some high-voltage wiring that was weakening at its solder joints, because it's very thin gauge and flexing was weakening it. I resoldered those joints, and that helped too.But those metal film resistors were definitely the major culprit.

This post is made possible by the generous support of people like you and our sponsors:
  Schiit Audio  

Follow Ups Full Thread
Follow Ups
FAQ

Post a Message!

 Forgot Password?
Moniker (Username):
Password (Optional):
  Remember my Moniker & Password  (What's this?)    Eat Me
E-Mail (Optional):
Subject:
Message:   (Posts are subject to Content Rules)
Optional Link URL:
Optional Link Title:
Optional Image URL:
Upload Image:
E-mail Replies:  Automagically notify you when someone responds.

[ Top Top of Page ] [ Contact Us ] [ Support/Wish List ] [ Copyright © 2024, Audio Asylum, all rights reserved ]
[ General ] [ Speakers ] [ Tubes ] [ Vinyl ] [ Digital ] [ Hi-Rez ] [ Video Asylum ] [ Cables ] [ Tweaks/DIY ] [ Music ] [ Films ]