50's wiring - weird interaction between vol and tone

stavrose

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Hi All,

Got a weird situation going on with my 50's style wiring.

Due to the guitar being bright on the bridge I changed the volume pot to a 250k (but I left the tone pot at 500K) and I changed the cap from a .22uf to .47uf (K40Y-9).

Now, when my bridge volume is at 10 and I roll down my bridge tone to zero, the volume completely cuts out! And in general, the sweep on the bridge tone knob is pretty awful - the treble doesn't really roll off much at all until the tone is down between 3 and 5. Also, the tone control now seems to really affect volume - as I roll down the tone from 10 to 5, the volume lowers considerably. Its almost behavng like a second volume control!

I'm wondering if I did something wrong - maybe the combination of a smaller volume pot value coupled with a bigger cap value has caused this - or maybe its just one of those two factors.

Maybe I should have changed both bridge pots for 250k instead of just one...

Any thoughts?

Thx, Stavs
 

Grenville

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Interesting.

I did something similar, put a 470k resistor on my 500k pot to bring the pot closer to 250k and it has worked well with no side effects like this.
 

moreles

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Sorry I can't help -- perhaps someone here has enough electronics knowledge to assess the pssible impact of those pot/cap values. I've stopped using vintage wiring because the interactivity can yield some great sounds but is too variable and unreliable for someone like me who really doesn't want to be tweaking knobs when playing. Good luck sorting this out. The wiring gurus on this forum are great but may need pics.
 

ARandall

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Somehow you're getting a ground via the tonepot. Which means something is off there. I'd probably agree that something internally is wrong with the pot itself as the cap should filter the frequencies affected.
50's wiring will make for more interactivity between V and T, so you will find the tone control dropping volume back a fraction. But its a minimal thing.
 

Standard

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I'm far from an expert, but it sounds like possibly a faulty pot. Or possibly a grounding issue.
 


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