Wah Grounding

[petemoore]

  I have wah buzz noise.
  Both my signal jacks are connected to the case, all grounds tested.
  I can't figure out why it's so noisy.
  I have two added mod pots, one for input and one for gain IIRC.
  BCxxx transistors DPDT bypass, 200k black pot..battery for supply tests.
  I can't use it like this.
  I don't see grounds marked by the signal jacks on the schematic, and remember diddling with a wah forever a long time ago, then testing to find it was using insulated jacks.
  http://www.geocities.com/CollegePark/Library/1355/voxwah.gif
  At one point both jacks got smashe-footed, so I replaced them, somehow I ended up with a purple and white wire, [ring and sleeve of jack] showing a ground connection, I can't say it isn't through the jack, I'm wondering what the purple and white wires go to...suppose I'll have to lift up and look under the board.