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Hoffman Amps Forum image Author Topic: Smoking 5F1 :help:  (Read 10670 times)

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Offline sluckey

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Re: Smoking 5F1 :help:
« Reply #50 on: September 26, 2014, 01:32:37 pm »
You have to look at the layout pic to see all the stuff Pete is suggesting. He modified the NFB circuit so he could put a bypass cap on the cathode of V1B. He also put a bypass cap on the cathode of V1A. Both of those bypass caps will significantly increase the gain of both halves of the 12AX7.

In addition, he's suggesting tweaking the 680Ω resistor he added to the NFB circuit. Making it larger will lower the NFB which will also increase gain.
A schematic, layout, and hi-rez pics are very useful for troubleshooting your amp. Don't wait to be asked. JUST DO IT!

Offline Stankfut

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Re: Smoking 5F1 :help:
« Reply #51 on: September 26, 2014, 01:50:17 pm »
Okay, that helps. I did look at the layout....that's the problem! I understand schematics a little better than layouts, so I couldn't quite picture what the changes were doing. Thanks!

 


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