tuning a wah for humbuckers vs. single coils

[powerplayj]

I noticed that on Geoffrey Teese's site, some Teese wahs were recommended for single coils while others worked better for humbuckers.  Since these are totally different wahs, I assume the difference must be in the inductor or pot since most of the other components can be tuned with a trimmer or switching mechanism.  Does anyone know what component is the most critical for determining how well a wahs works with either pickup type?

http://www.realmccoycustom.com/

[powerplayj]

weekend bump

[Paul Marossy]

Actually, IMO, it would be as simple as adjusting the sweep cap to compensate a certain type of pickup. I would personally make the sweep cap maybe 0.022uF for single coils and leave it at 0.01uF for humbuckers.

[Gringo]

Being able to control the gain  helps when using hot humbuckers, to avoid unwanted clipping when hitting hard.

[jonathan perez]

if you want to control the gain/bass, youd have to replace the 570-470 ohm resistor with the appropriate pot/resistor.

i agree with mr. marossy, but if you think .022 might be too much, then .015 or .012 will do as well.

but the inductor and pot dont make single coils sound fatter, thats for sure.

another thing to keep in consideration are the transistors. a pair of bc239c trannies are PERFECT for higher output pickups, or if youre into metal like me. 

on the other hand, something like a bc109 will have lower "gain", but a sweeter sound to it. much more useful when relying on a "true" toned wah (but any pair of bcworkalikes will do), for something that can be versatile for switching between a humbucker and single coil equipped guitar.

i bet teese's wizard wah would sound killer with single coils. i admit, i love the wizard wah to death. theres a part of me that wants to have that dual inductor, to switch between his and, say, a halo inductor...

but, ive got 6 wahs that all sound totally different...so...no need to destroy anything...why am i ranting?

[Paul Marossy]

the inductor and pot dont make single coils sound fatter, thats for sure.

Yep, that's true.

want to control the gain/bass, youd have to replace the 570-470 ohm resistor with the appropriate pot/resistor

That's another thing to try as well. People seem to have ahard time getting that resistor replacement just right, though.

with mr. marossy, but if you think .022 might be too much, then .015 or .012 will do as well.

Yeah, that depends on how thin you want your single coils to sound. I like a fatter, beefier tone myself.

but, ive got 6 wahs that all sound totally different...so...no need to destroy anything...

You, too?! 

[Eb7+9]

I can't say I have any idea what's specifically going on in the Teese wahs ... but, I did some analysis on the classic unbuffered VOX wah topology recently (them long rainy winter days) and noticed how PU inductance affects the mixing ratios taking place at the front of the loop - well, hot dang! ... if you model the PU as a simple voltage source you won't see any of this ...

In principle to get the wah sound on a single-coil using a bucker you'd have to set up a "desired" profile based on a specific single-coil pu driving/loading the circuit and then tweak circuit values to match profiles for a higher inductance/DC-resistance PU ... using first-order AC analysis to establish the transfer ratio values leading to the summing node (i) coming from the input and (ii) coming from the return path in the loop (Zin looking at the input of the loop is around 39k) ... obviously, these ratios would have to match if the overall filter responses are to be identical - that's in theory ...

If your wah is designed around this classic topology you can always try tweaking your way there by replacing the input 68k and feedback 1k5 with trimpots (100k/5k) ...

~jc

[Paul Marossy]

If your wah is designed around this classic topology you can always try tweaking your way there by replacing the input 68k and feedback 1k5 with trimpots (100k/5k) ...

My only comment is that it seems that when you alter that 68K input resistor too much, it messes with the volume of the wah circuit when it's engaged vs. bypassed. I guess if you do both of them, you ought to be able to find a good compromise.