What to do with Push-Pull pot in 5F8/6A

[ellum68]

I'm proud to say my little novice hands managed to assemble a properly functioning 5F8A Twin. I used a push-pull pot on the normal volume control, but am not sure what to do with it. Does anyone have a suggestion for a simple mod to put it to good use?

[MWJB]

2nd stage cathode bypass cap in parallel with the 820ohm resistor at V2 pin3? Bridge the switch contacts with a 100K resistor. Gives a gain boost, use a .68uf to 25uf cap

[JoeM]

MWJB has a good idea, I'd use a 1uf, but that's just my taste. Maybe something in the NFB might work too.

[ellum68]

Seems like I've done alot of talkin' to you lately MWJB, lol. I think I see what you're talking about. I see this same idea in the Tweed Super and Bandmaster. So I take one leg of the cap and drop it to pin 3 of V2 and then run it up to a switch lug, stick a 100k resistor between the switch lugs, and then finish by taking my other switch lug to a ground? This sound like the "Fat" switch in my Vibro-King that I've heard about.

[MWJB]

You got it, yes it is commonly called a "fat" switch. The 100K accross the switch reduces any popping, when you throw the switch, that you might otherwise get.

[loudthud]

The switch could be used to disconnect the unused channel at the mixing resistor. This gives a gain boost of about 6dB.

[pdf64]

A 'bright' switch, or to bring in an additional bright(er) cap.

[ellum68]

I finally got around to doing it, lol. I went with .25uf. It works like a charm!

[Gtr_tech]

A 25u you mean?

[ellum68]

Yes 25uf. My mistake