Gear whoring

Vox Clyde McCoy (Mod) Wah


 I started this project after breaking my V847a, the traces on the cheap PRC PCB lifted after attempting to replace the transistors.

So i figured id etch myself a PCB and make my own Clyde, with a few extra features.

My plan included

  • Vintage clyde layout
  • True bypass switching + LED
  • Sweep cap rotary switch (to allow adjustment of the sweep range.)
  • Vocal pot (To allow adjustment of the accent, changing from a wah to woh sound.)
  • Gain/bass control (To allow for more low end/allow me to add a gain boost with the pedal on.)
  • Mid control (To make the sweep smoother)

Heres the original clyde schematic
http://fuzzcentral.ssguitar.com/mccoy.php

I tried to recreate this as true as possible, while being on a restricted budget. I used the inductor from the V847a,  etched my own PCB freehand with sharpie, and ordered my parts from Musikding.de, i went with regular metal film resistors, 2 generic axial 22uf caps (mojo), i used a polarised 4,7uF electrolyic in place of the non polarised 4uf (hey, theyre hard to find!), the other 2 caps were SMF.

Here’s my ugly looking PCB after etching. (PCB etching tutorial)

After this i drew up my design with DIY Layout Creator.

Heres the result.

So it’s a bit untidy and hard to read, but its just an overview.

Next thing is to drill and arange all my parts.

Looks nice, i should point out before i go any further i had a bit of trouble later on in the build getting a wah sound from the pedal. What i didnt realise is the hot pins from the regular vox inductor are set diagonally and i only had 2 holes for the inductor. So i jumpered the cold pins to the hot pins and all was well.

The enclosure was drilled, and the pots were wired up as well as the board was soldered together.

Hmm, no PCB standoff, itd short out in the enclosure, and its pretty untidy.

Foam, pink tape and plastic tie tags. Solution to everything (especially pink tape).

Here’s a close up of the rotary. I used a 2 pole 6 throw plastic rotary so i could mount all the caps to the switch rather than having more mess inside the pedal.

This may be a little hard to understand so heres a GIF explaining the wiring a bit better.

On each rotation of the switch the 2 throws opposite will be connected to the poles. So youd just have to orientate the caps so it goes PCB -> pole 1 -> throw -> other throw -> poles 2. Check it out with a multimeter if you dont follow, you need to make sure none of the legs of the caps touch each other, any of the throws besides the ones theyre soldered too or the main poles, which can be a bit tricky to do, use some electrical tape/heatshrink

This is a huge improvement over the V847a, i tend to just set and forget it for the best all around tone for both cleans and gain. Maybe trimmers wouldve been a better idea, i dunno, but it wouldnt be as cool.

Notes
On my original design I wanted to use a potentiometer to dial between the treble and bass frequencies (or between 2 capacitors in paralell), though it didnt seem to go to plan. I believe the resistance from the pot was causing some problems, i only seemed to get a wah sound at either extreme of the pot rotation. So i swapped it for a rotary switch which works much nicer.

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2 responses

  1. Charles england

    hey, thanks for putting up a non working layout.
    you have the power going into the base of Q1 and the input going into the collector
    Please correct this, your layout is wrong…..

    August 27, 2013 at 1:39 pm

    • Sorry it took a while to get back to you aha. The transistors aren’t labelled as so it depends on what transistor your using. Using a 2n5712 transistor here, the orientation is correct for this transistor. You will have to figure out your own orientation with a schematic.

      October 3, 2015 at 9:07 am

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