Let's Get Technical > Troubleshooting Problems
4ohm Resistor Across C131 & D38 ?
red2203stack:
Thanks for the welcome rnolan. I previously emailed MJMP about an effects return jack. The one part I can't find anywhere. Will ask him if he's ever seen this. Thanks again
MarshallJMP:
Yep seen this before, ADA used a different brand of transformer (Taiwanese) and this one put out more voltage to the filaments and also to the 5V regulators. I think they put it in there so the 7805 won't heat up as much, you will get a voltage drop over the resistor so the 7805 get's a lower voltage which results in less heat in the 7805.
red2203stack:
Oh ok, that explains it. Thanks for the reply MJMP. I Replaced the 6 diodes with new 1n4007's and changed the 2200uf & 3300uf caps. Now i'm gonna have to wait on a new 4ohm resistor, closest i have is 5.6ohm. The original was 5w ceramic wirewound. Is that the best option for that?
Dante:
You guys talk funny
MarshallJMP:
--- Quote from: Dante on January 09, 2019, 10:07:22 PM ---You guys talk funny
--- End quote ---
;D :thumb-up:
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