Does a resistor in series with a pickup change the tone?

[Pete Stevens]

I've read that every resistor has some parasitic capacitance and therefore has the ability to filter high frequency signals. I wondered if that would matter in practical terms in guitar wiring. I'm specifically interested in the effects on tone of regular 250k or 500k audio pots wired as a simple blend pot without a lug going to ground.

 

[ToneFiddler]

Re: Does a resistor in series with a pickup change the tone?

I've read that every resistor has some parasitic capacitance and therefore has the ability to filter high frequency signals. I wondered if that would matter in practical terms in guitar wiring. I'm specifically interested in the effects on tone of regular 250k or 500k audio pots wired as a simple blend pot without a lug going to ground.

short answer:
yes, a resistor in series with a pickup will change the tone. i will kill treble.
BUT NOT because of the parasitic capacitance of the resistor. it's insignificant.
It'S because of the High Impedanz of passive Pickups.

 

[Teleplayer]

Re: Does a resistor in series with a pickup change the tone?

The series resistance of a blend control has two effects:
1) It isolates the resonance of the pickup from the guitar cable capacitance and also isolates it from the other pickup. When the pickup is isolated from the cable capacitance and also the inductance of the other pickups, the pickup resonates at its self-resonance frequency. The self-resonance frequency is higher than the loaded resonance frequency, which you may hear as being brighter, or sometimes you hear it as a loss of treble depending on various factors.
2) You are also losing treble because the capacitive loading of the the guitar cable together with the additional series resistance of the blend control acts as a low-pass filter.

 

[Bronze Buzzard]

Re: Does a resistor in series with a pickup change the tone?

Don't get too caught up in the snake oil, yo. Try it a couple of ways until it suits you.

Don't ever forget that the end result is about sound, and beauty is in the eye of the beholder.

Does is sound good?

 

[beaubrummels]

Re: Does a resistor in series with a pickup change the tone?

I had a ‘52 Tele style blend pot in my Tele for a while and it didn’t lose treble or affect the sound negatively when turned to different positions. It worked like a charm, as expected. I think I used a no-load so when it was on it was fully on? It’s been a while.

 

[freefrog]

Re: Does a resistor in series with a pickup change the tone?

I'm specifically interested in the effects on tone of regular 250k or 500k audio pots wired as a simple blend pot without a lug going to ground.

Even without a lug to ground, normal pots used as blenders still put a massive amount of resistance between each pickup and the output.

I post below a simulation showing the resonant peak of two 6k Strat PU's in parallel (red curve) vs the same thing through a regular 500k pot wired as a blender (in grey).



The output level is +/- 6dB lower through the blender. To obtain the same thing from the 2 PU's in parallel without blender, I'd have to lower the overall volume pot to 80% (with a linear 250k volume control).

NOTE -If you want a blender which is not actiing as a volume control permanently lowered, you need a dual control like this: https://www.stewmac.com/electronics/components-and-parts/potentiometers/alpha-blend-pots.html

FWIW.