Noise when volume pot turned off

[Shreddiekrueger]

Hi all,

I've recently built my first warmoth tele. I have a single humbucker and volume pot, and I'm pretty sure the wiring is correct. The humbucker works as it should with the pot turned up, but with the pot turned off I have a fairly loud hum similar to as if the instrument cable was disconnected entirely from the jack.

I'm sure its some kind of ground issue, but all of my grounds (from humbucker, jack, and volume pot) are soldered to the back of the volume pot. I did have some trouble soldering to the back of the pot, is it possible the heat damaged the pot?

 

[line6man]

A properly wired single volume pot will short the output at 0 Ohms. If you are still able to hear noise, that would indicate the pot is not grounded properly, and thus, is only placing a series resistance between the pickup and output, until the pickup is effectively removed from the circuit. This is equivalent to an infinite output impedance at the jack.

Double check to be sure that the third terminal of the pot is grounded, and that all ground points make 0 Ohm continuity. If that fails, check the resistance of the pot at the "0" setting. It should read 0 Ohms.

 

[lafromla1]

I had a volume pot that was heat damaged when I had someone else solder it.  Sounded like the same issue you are having.  I just replaced the pot and soldered it myself, now it works fine.....and now I do all my own wiring  :icon_thumright:

 

[Torment Leaves Scars]

Do you have a tremolo on the guitar?  Reason I ask is because I had some static from my volume pot, and it wound up being because I didn't have a ground wire going to the tremolo.  :help:

 

[line6man]

Do you have a tremolo on the guitar?  Reason I ask is because I had some static from my volume pot, and it wound up being because I didn't have a ground wire going to the tremolo.  :help:

Again, a properly wired volume pot will provide a 0 Ohm impedance at the output when rolled all the way down. This means there is no current flow at the output, and the gain stage you have the guitar plugged into cannot conduct. In reality, the impedance is actually fractions of an Ohm, to perhaps a couple of Ohms, depending on the series resistance of your cable, but the voltage and current induced into the cable by outside sources is not enough to cause an audible signal for a gain stage to conduct and amplify, and in any case, would exist beyond the output of the guitar. It is highly unlikely that any noises caused when a properly wired volume pot is rolled all the way down could be related to the presence or lack of a bridge ground.

Of course, this brings me back to the theory that the volume pot is not properly shorting the output.

 

[Torment Leaves Scars]

Do you have a tremolo on the guitar?  Reason I ask is because I had some static from my volume pot, and it wound up being because I didn't have a ground wire going to the tremolo.  :help:

Again, a properly wired volume pot will provide a 0 Ohm impedance at the output when rolled all the way down. This means there is no current flow at the output, and the gain stage you have the guitar plugged into cannot conduct. In reality, the impedance is actually fractions of an Ohm, to perhaps a couple of Ohms, depending on the series resistance of your cable, but the voltage and current induced into the cable by outside sources is not enough to cause an audible signal for a gain stage to conduct and amplify, and in any case, would exist beyond the output of the guitar. It is highly unlikely that any noises caused when a properly wired volume pot is rolled all the way down could be related to the presence or lack of a bridge ground.

Of course, this brings me back to the theory that the volume pot is not properly shorting the output.

What was happening with mine was that I would get static from my volume pot when the volume was turned up (obviously), but what was really weird is that whenever I literally just touched the knob with my finger, the static would disappear.

 

[iamdavidmorris]

Just some basic things to check here, but if all your grounds are together, I assume that means they also touch the ground wire(s) from the pickup, the bridge, and the output jack.  Also, make sure none of your wires are accidentally touching something they shouldn't.

 

[Jusatele]

don't turn off the pot

 

[line6man]

but what was really weird is that whenever I literally just touched the knob with my finger, the static would disappear.

That's not weird at all, it's very normal.

 

[Torment Leaves Scars]

but what was really weird is that whenever I literally just touched the knob with my finger, the static would disappear.

That's not weird at all, it's very normal.

Why does this happen?

 

[Cagey]

Tone worms don't like to be touched while they're mating.

 

[line6man]

but what was really weird is that whenever I literally just touched the knob with my finger, the static would disappear.

That's not weird at all, it's very normal.

Why does this happen?

Because you are grounding your body, which is otherwise, a big antenna.

Also, toneworms don't like to be touched while mating. :blob7: