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Old 7th April 2004, 06:38 PM   #1
00940 is offline 00940  Belgium
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Default 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 ? :

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Old 7th April 2004, 10:32 PM   #2
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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.

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Old 7th April 2004, 10:51 PM   #3
EC8010 is offline EC8010  United Kingdom
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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).
The loudspeaker: The only commercial Hi-Fi item where a disproportionate part of the budget isn't spent on the box. And the one where it would make a difference...
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