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Replacement rectifier diodes for 140B amp?

Started by wordsandsigns, January 19, 2023, 05:29:46 PM

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wordsandsigns

Hello!  I am working on repairing the amp in my 720A "B era" console Wurly (see https://docwurly.com/700-series-consoles-keep-em-straight-720-720a-720b-726-b/)

I accidentally shorted the rectifier diodes and blew a fuse.  I'm attaching a picture of the shorted diodes and a pdf of the amp schematic (the diodes are D63, D65, D66 and D67 on the schematic).

If I need to replace the diodes, what should I replace them with?  Anything special?  The diodes are marked "6743".

Very happy to find this forum, I've just been bugging the kind people at the Tropical Fish Vintage Wurly hotline and I think they'll be happy not to hear from me for a second  :P

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Jenzz

Hi :-)

The diodes have to handle the current of the power amp, so i would recommend something like the 1N5401 - 1N5407.

Jenzz
Rhodes tech in Germany
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wordsandsigns

Wonderful, thank you!

I replaced them with the 1N5401 and the amp is no longer blowing the fuse.   It does have some other issues which I will post in a new topic.

Thanks again!