RESISTOR TAPPING HBs--What really happens to the grounded coil?

[ViperDoc]

When resistor-tapping a humbucker (placing a switched resistor to ground on the in-between leads), the remaining single coil's ground reference is artificially lifted by the value of the resistor. Right?

What happens to the grounded coil? Is it entirely rendered to ground by the full ground connection, or does it add anything back to the split tone by virtue of the 2K2 resistance? Like is there a full-up 2K2 pot "open on the dead coil"? Or is it just the live coil lifted by the 2K2 resistor? What say you?

See scribbles here:

HUMBUCKER RESISTOR TAP.pdf

[martin manning]

What happens to the grounded coil? Is it entirely rendered to ground by the full ground connection, or does it add anything back to the split tone by virtue of the 2K2 resistance? Like is there a full-up 2K2 pot "open on the dead coil"? Or is it just the live coil lifted by the 2K2 resistor?

The grounded coil has a 2k2 load, reducing it's output significantly. The output coil is stacked on top of that reduced output.

[ViperDoc]

The grounded coil has a 2k2 load, reducing it's output significantly. The output coil is stacked on top of that reduced output.

Great, thanks Martin. So the answer is "both", but it varies depending on the ground reference resistor value/grounded coil load. So a fraction of the grounded coil's output is essentially added back to the raised single coil, and is therefore partially humbucking. I love this technique, personally. The PRS 1k1/2k2 setup on neck and bridge vintage PAF-type HB pickups respectively sounds amazing.

[martin manning]

Yes. The smaller the resistor the less hum bucking you get, and the lower the output. Do you hear more single coil-like hum with this configuration?

[ViperDoc]

Yes. The smaller the resistor the less hum bucking you get, and the lower the output. Do you hear more single coil-like hum with this configuration?

It's not too noticeable, so long as the grounding scheme is good (a la Fralin). "Nude-tapping" humbuckers has always produced meager tones and the most hum IME, so I like this approach. I tend to put it in all my harness-swapped guitars. 1/4-1/2W MF does the trick. If I can, I try using the larger CTS enclosed switch pots with the PCB-like solder lugs. The switch click is nice and stout, and they turn smoothly; although the stock PRS tone pot holes need to be reamed for the larger (than Alpha) diameter posts.

[dorrisant]

Try using a small cap to from the center tap to ground. Experiment with values.