Fender 6G6 (A or B)

[Mark]

I think you'll find the taper of the pot is important. The pot should have a full range. The treble and bass pots in my 6G7a Bandmaster are brillant.

[LarryLarry]

This seems like the right place to ask, so here I go. Can one of you fine builders confirm or correct my initial wiring of the 70k tap for a 6G6B?

[Mark]

I bought one of those pots as a spare if one should go in my amp.

I'd imagine after measuring 350K across the pot, you'd then measure 70K from the tap to one end of the pot would confirm you have the 0.003uF cap in the right place.

Have you tried this?

[LarryLarry]

I get a reading of 45k across the outer 2 terminals on the pot. Either that is pretty far out of spec, or the point at which it reaches 70k during the sweep occurs when it should. Not sure about the CW / CCW deal...

[Mark]

I've looked at my replacement pot (same as your pot) and measured it.

Your wiring appears to be incorrect.

Looking at the back of the pot the first terminal on the left goes to the bass pot (the tap is off this side of the pot.)

The second terminal (starting from the left side) goes to the volume control.

The third terminal goes to the 250pF treble cap.

The further-most right terminal has the 0,003uF cap to ground attached.

I hope this helps your build.

P.S. The taps on my pots measure 47K and 58K agreed it isn't 70K, the pots themselves measure 370K and 392K. That's sloppy 50's tolerances for you.

[LarryLarry]

Thanks Mark, I will re-wire and proceed.

It's .005 to ground, not .003, correct? I'm using a .0047 anyway...

[Mark]

I've checked the circuit diagram and the value is 0.005uF. I would go with a 0.0047uF cap.

I wouldn't imagine that you would hear much difference between how you had the treble pot wired and how it should be wired.

The taper of the pot is another thing to consider, these new pots have 10% of the pot value at 50% rotation of the pot. I'm led to believe the older pots had 30% of the pot value at 50% rotation of the pot. I will have to check this out though.