Curiouser and curiouser

My new Patch of Shades is not like my "old" Patch of Shades, it turns out. Somewhere between the manufacture of PoS #45 and PoS #103, the design changed quite a bit. Different circuit board, different IC layout, possibly different ICs, different input and output jacks, though we may never know if the chips are DIFFERENT, since the early models have sanded off part numbers for the key chips. The chips on #103 are NOT sanded.

#103 arrived pretty much non-functional, but only because the pressure pad was not working. As readers of this blog may know, pressure pads are something we know a little about. However, the pressure pad on #103 was totally unlike that described in previous blog posts. 

It was, in fact, more similar to what I originally thought the PoS pressure pads were like, before I took my first one apart. The intertwined fingers circuit board was the same, but the contact surface was indeed like the piece of magnetic tape I imagined when I first got my PoS. However, it was completely non-conductive, infinite ohms at all points. I called my friend Yona (lightatplay.net). He suggested checking the circuit board by shorting it with tin foil, and he also mentioned graphite being used as a variable conductive material. The foil completely shorted the circuit, but, by taking a #1 pencil, and coating the plastic sheet with the black paint on it with graphite, I was able to return the pressure pad to functionality. I erased some of the graphite, and I also added some paper padding to lift the plastic away from the circuit board, and put some foam padding above it, to make more pressure necessary to manipulate the sound.

The new PoS is still a little overly sensitive, but a few more tweaks and it ought to be dialed in perfectly. In fact, now that I know about the graphite effect, I am going to reopen my #45, and make that pad a little more sensitive as well. I may also add some padding to it, too, for easier articulation.