diyAudio (
-   Tubes / Valves (
-   -   How to check output transformers ? (

00940 7th April 2004 06:38 PM

How to check output transformers ?
I've been given a pair of output transformers by a friend. Is there a quite easy way to test them ? I've no oscillope at home, just a dmm. All procedures I found on the web take for granted that the xformers are still on the amp.

They're quite small, coming from a stereo amp with just a pair of EL84. There are four wires coming out of each xformer.

Btw, would someone know from which brand are tubes with this marking ? :

fdegrove 7th April 2004 10:32 PM


The CV letter code FB is probably STC in Footscray.

KB I see alot on CV valves but I don't know what it stands for.


EC8010 7th April 2004 10:51 PM

I'm afraid your output transformers are traditional 3W single-ended transformers and are probably terrible. On the other hand, if you want to experiment and learn, then they are ideal. Try looking at the Mullard 3-3 circuit. The winding with the higher resistance is the primary, and goes between HT and anode. The (much) lower resistance winding is the loudspeaker output (probably 4 Ohm).

All times are GMT. The time now is 01:07 AM.

vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2015 DragonByte Technologies Ltd.
Copyright 1999-2015 diyAudio

Content Relevant URLs by vBSEO 3.3.2