Capacitors and Pickup frequency response

[db3266]

I'm trying to decide whether or not to make some more changes to the wiring of my Telecaster harness. I think the bridge pickup is bright, too bright for what I play (I always think bridge pickups are too bright on any guitar). I have a 0.022 cap installed.

I have three options.

1. Install a larger cap, maybe a 0.033

2. add a resistor as per the Bill Lawrence schematic, which will tame the highs off the bridge.

3. add more capacitance into the circuit when the bridge pickup is engaged, ie, I could have a 0.022 in the normal position which will be used for neck and middle position, then add another cap (wired to the switch) with a value of my choosing, so that when the bridge is engaged, both caps are used.

I dont know what the trade off is between adding a resistor or adding an extra cap? I read that capacitors change the frequency range of the entire pickup, I'm really not sure what that means?

 

[freefrog]

Adding a resistor will give a "rounder" frequency peak, as if you lowered your tone pot. Il will sound softer and more open.

Adding a cap of really small value will shift down the frequency of the resonant peak, as if you used a longer cable. The resonance will take a "narrower" place in the frequency spectrum than with a lowered tone pot and might become nasal in some cases.

I don't comment the idea to mount a tone cap of a larger value: experiences about that appear to differ so widely that any comment becomes risky (you have no idea how it's dangerous to evoke the tonal FX of caps for the humble typical anonymous forumer; LOL).

If you want to try the second trick (small cap in parallel with the pickup), I recommend you to try Styroflex caps of really low values: 120pf, 220pf, 270pf, 330pf and so on. Beyond 1000pf, the sound might become unnatural. And FWIW, each time you add 150pf in parallel with the PU, it's as if you added 1m to your guitar cable (if it's made of typical wire).
Styroflex caps are not expensive, BTW.

Hope to be useful. I'll try to post screenshots showing what I explain later today.

 

[freefrog]

OK. Below is the frequency response of a pickup (FilterTron style) without tone pot (in white), with a tone pot @ 5 (in green), then with a 3300pf cap in parallel with the pickup (in blue).

The green line is what you'd obtain with an added resistor.

The Blue line is the kind of tone obtained with a cap paralleled to the pickup - and it matches 22m of typical cable in this case!

 

[db3266]

thanks.
I think I might try the resistor option.

 

[jamman]

Way over my head , But I'd try a .033 or .047 cap 1st. Just easier to do and undo if it doesn't get you where you like it . I tend to go for the simple first ,test , and then see how I feel about the change . It's in the ears , for me .