Home OTL Asylum

OTL, Output Transformerless Amplifier User Group.

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

Re: DIY

All the tube sections in each phase of the output circuit are in parallel with each other and driven by a single driver tube section. One of the later mods to the output circuit includes the installation of very low value resistors, one in series with each plate or cathode of each output tube. (I think Ralph finally settled on installing them on the plate side of the circuit.) If you have these resistors installed in your amplifier, and if you can detect a voltage across one of these resistors, you could calculate current using Ohm's law. Since the tube sections are in parallel, you would unavoidably be measuring the total current, but if there is no detectable voltage across a given plate resistor, that would indicate that the tube under test is a "dead" short. So you cannot use this method to tell whether one tube vs another is current hogging, but it might work to tell you that a given tube is kaput. I am feeling insecure in writing this without having looked at the schematic in months, so if Ralph or anyone else thinks I am wrong, please do jump in and say so.

This post is made possible by the generous support of people like you and our sponsors:
  Analog Engineering Associates  

Follow Ups Full Thread
Follow Ups
You can not post to an archived thread.

[ 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 ]