4uf cap in a wah?

[AC30Dirty]

hey guys. Im currently working on a wah project. Im having a hard time finding a 4uf capacitor to use instead of a 4.7uf electrolytic cap. Im trying to take a the wah to vintage specs. I was wondering though, if I could use 4 1uf stacked metal film caps (small ones from digi-key) connected in parallel to equal 4uf here?  thanks

[Paul Marossy]

I was wondering though, if I could use 4 1uf stacked metal film caps (small ones from digi-key) connected in parallel to equal 4uf here?

Yep, you sure could.

[Connoisseur of Distortion]

what's that cap being used for??

[warioblast]

I have one half OT question 
How does it affect the tone of the wah when you put a 10uF cap instead of the 4uF cap  ?

[rockgardenlove]

Juse use 4.7 uF...It should work ok, what type of wah are you building?

[AC30Dirty]

thanks guys for the feedback! Im taking my VOX V847 wah and converting it to vintage McCoy specs based on the info I found at Fuzz Central. On the info it describes that the electrolytic cap in the circuit is a 4uf instead of a 4.7uf. Does this actually make a difference in the overall wah tone?

[Paul Marossy]

On the info it describes that the electrolytic cap in the circuit is a 4uf instead of a 4.7uf. Does this actually make a difference in the overall wah tone?

I would think not, but some people might claim to be able to hear a difference. The 10uF is reported to make it sound a little fatter, but I haven't personally tried this yet.

[R.G.]

On the info it describes that the electrolytic cap in the circuit is a 4uf instead of a 4.7uf. Does this actually make a difference in the overall wah tone?

Not really. The originals were integer-value caps because the industry used to make 1uf, 2uF, 3uF, 4uF and 5uF caps before they standardized on the EIA equal-percentages values of 1uF, 2.2uF, 3.3uF, 4.7uF, ... The tolerance of an electro is often as much as +80%, -20% as well, so getting 4.000uF in there for the cap is not going to do much.

How does it affect the tone of the wah when you put a 10uF cap instead of the 4uF cap  ?

The capacitor in question is there to act like an AC short to ground for one end of the inductor. It's designed to be less than the inductor's impedance at all frequencies of interest. We have a nominally 0.5H inductor, so at the lowest guitar frequency, its impedance is Xl = 2*pi*f*L, or 2*3.14*82*0.5 = 257 ohms. The cap's impedance there is Xc=1/(2*pi*F*C) = 1/(2*3.14*82*4.7e-6) = 413 ohms.

Oops, didn't make it quite. Doubling that to 10uF would only make it 207 ohms, still quite comparable to the inductor's impedance. So whether that cap is 4, 4.7, or 10uF will make only a subtle difference. But there is the possibility it could be audible.

The question then is what is the effect of that cap being non-ideal? I think what it does is that it widens the resonance in the low bass, and makes the tone more of a bass boost and less of a "honk". That would explain some people hearing a "fatter" tone with a bigger cap.

[warioblast]

That's what I call an ANSWER.
thx R.G 

[AC30Dirty]

thanks guys for all the feedback! It really helped alot. I'll try out some stuff and get back to you guys on this post!

[alderbody]

Doubling that to 10uF would only make it 207 ohms, still quite comparable to the inductor's impedance. So whether that cap is 4, 4.7, or 10uF will make only a subtle difference. But there is the possibility it could be audible.

I used to have a 10uF in my wah (electro or NP) and i used to like it.
One day i decided to try some different caps/values in there and soon after i went back to the "nominal" 4.7uF electro.

It just sounded the most "traditional" of all....