Wiring problem 1HB, 1 single coil, volume, no tone control

AustrianJohn

Guitar has 1 single coil, 1 humbucker, 1 volume control, no tone control. Wiring diagram used is this: https://guitarelectronics.com/1-humbucker-1-single-coil-3-way-toggle-1-volume-00/

Instead of controling the volume, the pot acts like a tone control.

I've checked the wiring and solder joints, all looks fine. Everything is correctly earthed.

Humbucker is Iron Gear Blues Engine. Black and shield earthed, green and white connected and taped, red to switch.

Any ideas?

Funkfingers

A photograph of your actual wiring would be helpful.

What resistance value is the pot?

It is possible that repeated heating with a soldering iron has damaged the innards of the pot.

AustrianJohn

https://www.dropbox.com/s/1eknwwskfltts0y/wiring.jpg?raw=1

Pot is B500K

If all else fails I'll replace the pot.

FelineGuitars

Most likely the back of the pot is either not connected to earth or that the tag that is supposed to be connected to earth is not actually connected.

Also

The barrel jack is a stereo one .

Check you have the right tags connected .

AustrianJohn

Thanks for your suggestions @Funkfingers @FelineGuitars ;

I've replaced the pot with a new A500K. Will check out the jack wiring later.

Funkfingers

Looked at the photograph. Unfortunately, the bits that I needed to see heard obscured behind other bits. 

ICBM

FelineGuitars said:

Most likely the back of the pot is either not connected to earth or that the tag that is supposed to be connected to earth is not actually connected.

+1

A common failure point is the rivet where the ground terminal is attached to the trackboard, often strained when the terminal is bent back to solder it to the casing. Squeezing the rivet hard with some fine-nose pliers will often fix it.

FelineGuitars said:

The barrel jack is a stereo one .

Check you have the right tags connected .

On this type of jack, if it's not being used for stereo or an active circuit battery switch, always connect *both* the ring and ground connections to ground - this greatly increases the reliability of these unreliable jacks by almost guaranteeing that the ground contact can't fail... leaving only the tip contact as the weak point.

AustrianJohn

The jack is broken, there is no signal at the tip. I'll replace it tomorrow.

Dave_Mc

ICBM said:

On this type of jack, if it's not being used for stereo or an active circuit battery switch, always connect *both* the ring and ground connections to ground - this greatly increases the reliability of these unreliable jacks by almost guaranteeing that the ground contact can't fail... leaving only the tip contact as the weak point.

Does that apply to all stereo jacks? I just kept the stereo jack in my Jackson when I converted the active EMGs to passive Alegrees, if it helps I can rewire the unused contact to ground as well...

ICBM

Dave_Mc said:

Does that apply to all stereo jacks? I just kept the stereo jack in my Jackson when I converted the active EMGs to passive Alegrees, if it helps I can rewire the unused contact to ground as well...

Yes, although with a standard open-frame type the improvement is smaller since they’re less unreliable in the first place.

But basically, you can always connect unused contacts to whatever they’re in parallel with to gain a ‘backup’ connection in case the first one gets dirty/corroded/stressed and isn’t making a reliable contact.

AustrianJohn

Replaced the jack, wired as @ICBM suggested. Volume pot now controls the volume. 

Dave_Mc

ICBM said:

Dave_Mc said:

Does that apply to all stereo jacks? I just kept the stereo jack in my Jackson when I converted the active EMGs to passive Alegrees, if it helps I can rewire the unused contact to ground as well...

Yes, although with a standard open-frame type the improvement is smaller since they’re less unreliable in the first place.

But basically, you can always connect unused contacts to whatever they’re in parallel with to gain a ‘backup’ connection in case the first one gets dirty/corroded/stressed and isn’t making a reliable contact.

Thanks