Morley PWV Wah Volume Modding!

[trevorus]

I just got one, and I am looking to make this thing a bit more adjustable. The low end of the wah travel is a bit too dull and muffled, but the top end is pretty nice. That's really my only complaint. The volume sweep is perfect.

To get adjustability, would it be best to do the potentiometer on the photoresistor side, or the LED side? Any suggestion are welcome!

[Cliff Schecht]

Got a schematic?

[trevorus]

[Seljer]

Do a search on here, I can't remember who did some experimenting to find out what things to change to make his Morley wah sound better

[5150]

1: Contact Morley.  They have schematics on their site, and their tech support guys are some of the nicest I've ever talked to.  They'll gladly give out tweak suggestions, explanation as to what components do what, and even LDRs for their pedals if you think something is 'funny'.
2: If I'm not mistaken, that's an electro-optical pedal - moving the LEDs and LDRs towards and away from each other will change the maximum light contact, which changes the location of the extreme ends of the pedal.
3: In addition to the above, if you actually look at the aperture between LEDs and LDRs (its movement because of the pedal controls how much light goes through, which in turn controls how much the LDRs behave in the circuit, replacing the typical potentiometer setup) it'll be somewhat like (rough sketch)

|--------------\
|                    |_______
|                    _______|
|                    |
|--------------/
     
                   ^
which, obviously, can create a small 'hump' at the point indicated by the ^ (that's not actually on the pedal, I'm putting it there for clarification).  The simplest solution to this is to widen the gap to the right of that 'hump' at the ^ and then fasten some tape diagonally to create an arrow-like, parabolic, or logarithmic (depending on your patience level) shape, and tweak it around a bit until it sounds natural.

Jeff

[Meanderthal]

 Yeah, there's no pot to replace for a different taper. The only problem(and if it works for ya, who cares?) with messing with the hole in the cardboardish  divider thing is once you butcher it , it's permanent. It'll be black tape forever. But, yeah, that is what determines the sweep- the shape of the hole(which, btw, is the same for the volume part of the circuit). Personally, I widened the open end of the slot a little, and that was enough to make me happy with it...

[5150]

You could also cut out the entire section around that, a nice big rectangle of plastic, that would preserve that original hole and leave you with a LOT more black tape to use (but still 100% replaceable).  There is, however, no point that I can see to it, as it isn't that special a hole anyway - that 'hump' annoys the hell out of me, but now that mine's gone I have a killer wah to play with.

Jeff