Volume pot question.

Started by pjones78, May 12, 2016, 09:58:00 AM

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pjones78

this may be a dumb question, but I'm scratching my head on it. I just finished building a 6 position varitone pedal with volume. Everything works great, except the volume. It doesn't have any sweep range to it. It basically goes from on to off. No change in the volume. I'm using an A100 pot with lugs 1 and 2 attached to the circuits output, lug three as ground. Is that incorrect? Or did I use the wrong pot? Its a very simple circuit, a rotary switch with my 6 caps mounted directly to them, center lug on the switch as the input/output, free legs on caps as ground. 3pdt switch with LED. Effect switching works great, no pops, rotary switch works great through the different tones. Volume, works but it doesn't at the same time, like I said. No sweep to it, just Full blast and off.

Thanks in advance if anyone is able to help me with my mess up.

M.A.P

Try to connect your volume pot like this:

Lug
1 - ground
2 - output jack
3 - output of your circuit

thermionix

What MAP says is correct, and should work like a volume pot for you.  I think you might want a higher value pot than 100 ohms, though.  Probably more like 100K-500K, maybe even more.  Depends on what you're using the pedal for.

GibsonGM

Look closer at your pot...does it say "100KA"?   100 ohms, audio taper, not as common...anyway, like Thermionix suggests - something close to your guitar pot might be a good values...250k, 500k, 1M...but try any you have, of course...
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pjones78

Gibson, mine actually say a100k.  Should I maybe re wire like M.A.P says to and move up to maybe a 250?

ashcat_lt

Is this intended to be the first thing after a passive guitar, or to come after pedals?

If it's the first thing after the guitar, it's probably better to use a bigger pot.  Otherwise, I don't think it much matters.

Definitely do wire it as MAP says.  Otherwise, it's not an actual potentiometer but a rheostat, and can't work properly.

GibsonGM

^ Yup, what he said.    Altho 100k will WORK, just not as well as with an impedance that is more "guitar like"....
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MXR Dist +, TS9/808, Easyvibe, Big Muff Pi, Blues Breaker, Guv'nor.  MOSFace, MOS Boost,  BJT boosts - LPB-2, buffers, Phuncgnosis, FF, Orange Sunshine & others, Bazz Fuss, Tonemender, Little Gem, Orange Squeezer, Ruby Tuby, filters, octaves, trems...

ashcat_lt

100K will work fine as a volume control, but it might also suck tone (specifically kill tge resonant peak at the top end) if connected directly to passive pickups.

pjones78

Thanks guys! I'm going to re-wire today with the a100k and see how it works out. When I run the pedal, it will more than likely be at the end of the chain or by itself. I don't use a whole lot of effects, usually just a comp and a chorus, sometimes an echo. I appreciate the help!