Would this wah mod work? Plz hlp

[TKS]

      I have modified my vox v847 and I really like its sound but I turn my guitars tone control down when I use the wah.  I was wondering if it would be possible to add a passive (guitar style) tone control to the inside of my wah so I dont have to keep turning my guitars tone all the time.  Would the following schem work for this?  Am I completely wrong?  I am very new to this stuff and would like some feedback from people with more experience in this area.  Thanks

[lumpymusic]

      I have modified my vox v847 and I really like its sound but I turn
my guitars tone control down when I use the wah.  I was wondering
if it would be possible to add a passive (guitar style) tone control to
the inside of my wah so I dont have to keep turning my guitars tone all the time. ...

It would be simple enough to try. I think I would expect some volume loss.
Make up for that by reducing the size of that initial 68k resistor, maybe to
47k. Lowering that R would probably also lower the input impedance,
causing a little loss of treble, just what you appear to be seeking.

Alternative approach, raise the value of the input cap from .01 to 0.1
(just add some caps in parallel to test).
That might let a little more bass pass through and give the
overall effect of shifting the tone response down, perhaps
de-emphasizing the treble. I think I'd expect an increase
in volume with that mod.

The inside of a wah is a huge playground. You could mount
a weed-eater in there and still have room to experiment
with component values.

Lumpy

[Paul Marossy]

I think your idea would work OK. The only thing that might be an issue is a little bit of signal loss. If that happens, I think I would try changing the 470 ohm resistor on the emitter of the first transistor to maybe a 430 ohm or a 390 ohm or maybe even stick a 1K trimpot there. That way, you could keep the 68K resistor in place and make up for any signal losses by increasing the gain of the first transistor a little bit. I don't think it would change the feel of the pedal quite as much as changing the 68K input resistor to a 47K would.

[lovric]

that sure is a LPF and will work.  try bigger pot, in fact try the combination of a pot and cap that sits in your guitar since that combo is already in signal line  .

[lacto]

If you like the tone you achieved from your modifications I would be concerned about fooling with it. I consider the wah circuit to be fairly sensitive to most any component changes. What's so bad about having to adjust your guitar tone control? I am curious about this, please let us know how it works out.

[Paul Marossy]

that sure is a LPF and will work.  try bigger pot, in fact try the combination of a pot and cap that sits in your guitar since that combo is already in signal line

That might kill the tone a little too much, I would think.

What's so bad about having to adjust your guitar tone control?

If he's like me, he doesn't want to have to think about it. I would want it to be automatic when I switch on the wah pedal.

[aron]

I would certainly try it. I think it would be very much like turning your tone control on your guitar down.

[Paul Marossy]

Yeah, I think it's a good idea for those who would find it useful.