Little losses on 5 f1 negative feedback

[john_t]

I am a little losed on my Hoffman style 5f1 build. In particular the Negative feedback. I see the schematic has the secondary of the output transformer to the cathode of the preamp tube and to the tip of the speaker jack. I can not see or visulize it on the layout photos. Am I missing something


Thanks John.

[Willabe]

Look in here;

http://el34world.com/Hoffman/files/Hoffman_5F1.pdf

http://el34world.com/charts/Schematics/files/fender/Fender_champ_5f1_schem.pdf

http://el34world.com/charts/Schematics/files/fender/Fender_champ_5f1-layout.png

                       Brad   

[john_t]

Yeah, that's my problem I see the negative feedback going from the board to pin 8. On the layout diagram. I  don't see or understand the conection between the ot tranny  to the  jack tip to pin 8 I see in the schematic

[sluckey]

Oops! Looks like Doug forgot the 22K NFB resistor on the layouts. I'll call his attention to it.

[EL34]

Sorry guys.
I had the note on the board but forgot to add the resistor


I'll fix the layout diagram
thanks for the heads up

[EL34]

I fixed the layout on the 5F1 and 5F2A

You have to hit refresh on your browser to see the new version

http://el34world.com/Hoffman/files/Hoffman_5F1.pdf

http://el34world.com/Hoffman/files/Hoffman_5F2A.pdf


You can just attach the 22k to the existing lug and use some heat shrink and a wire to reach the speaker jack
I will add one more lug to the existing layouts for new boards

[sluckey]

Doug, you may want to mention NFB near the speaker jack on page 2 also.

[EL34]

will do, thanks

[EL34]

I uploaded new PDF files for 5F1 and 5F2A this morning
Page 2 shows has a feed back note at the speaker jack


I also uploaded new BOMs for 5f1 and 5F2A


Go here to get all the new files
http://el34world.com/schematics.htm


make sure you hit refresh on your browser after clicking on the links


Thanks for the heads up guys