Here is the 1981 Patch of Shades instruction brochure:

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.

Fergus Marsh

Yesterday my multi-year saved search in eBay alerted me to the presence of an ACTUAL Patch of Shades. It had a buy-it-now of $300, so I bought it now. I guessed that the owner had no idea what previous Patch of Shades had sold for on eBay. I bought mine for $520. The next one, purchased by audities.org, a museum of electronic music rarities, fetched $1200.

 What I didn't know was that the seller was none other than Fergus Marsh, brother of Hugh Marsh, and Bruce Cockburn's stick player in the 1980s! I flipped when I saw who I had Paypalled money to on my bank statement this morning. I emailed him, and he sent a very sweet reply, even telling me which "Brucie" songs he had used the effect pedal on.

I wrote: "Holy Wow!!!!! You're Fergus Marsh?!?!?!? As in, played stick with Bruce Cockburn? I am not a big follower of stick, but you are my absolute FAVORITE stick player. Thanks so much for all the gorgeous sounds over the years!! David"

Fergus replied: "Hey David, thanks for the kind words. Just to let you know, i used the patch of shades on a couple of Brucie tunes. Down where the death squad lives was one of them. I used a flanger in the loop that engages with the wah effect. It was pleasingly nasty. ( on the bass end of the stick) Hope you enjoy it. Ferg"

 Wow!

The Foot Pedal Repair

Gosh, this took too long to get to. I did this repair on April 27, 2010, and have not written about it as promised for almost three years. Result: successful revival of weapon of sweet distraction. OK, here is the revelation:

The first photo shows the foot pad pulled off the orange housing bay, and the top part of the pad slipped out of the enclosure and placed to the left side of the enclosure. In the black enclosure is the circuit board revealed in photo 2 below.

On the the right side of photo 2, you are looking at a firm ivory colored piece of plastic with a black rectangle rubber with a conductive set of bars printed on to it. This conductive pattern is placed at a 90° angle to the gold patterned circuit board revealed on the left. The circuit board consists of two disconnected circuit patterns connected to two wires that lead back into the main Patch of Shades enclosure. When the conductive black rubber is pressed against the circuit board lines, the circuit closes, the resistance is lowered as more pressure is added. 

 Photo 3 shows why my Patch of Shades was not working. A line of corrosion had made its way across the circuit lines, interfering with the pressure pad.

 Some of the corrosion might have made its way onto the conductive pad as well.

 Water, toe sweat, circuit board cleaning fluid, manufacturing by-product? We will never know...

 Scrubbed both boards all clean with an acetone based circuit board cleaning fluid (probably not so good for the atmosphere, but cleans better than alcohol).

 The key to easily putting it all back together...hot glue gun!!!! A hot glue gun will make it easy to re-wrap each piece of faux leather tightly enough, and also makes it easy to firmly remount the pad into the orange foot pedal area. Also, hot glue, while being a good tight hold, can also be peeled off and done over easily. I took advantage of this feature of hot glue several times during this repair, as I initially did not place the conductive pad in the correct orientation with the circuit board. If you are attempting this repair, careful observation of orientation during take apart will save you trouble later on.

The reassembled but not yet glued down pad is seen in the last picture.

In my next posting (whenever that occurs), I will upload some MP3s of the sounds that the various settings on the Patch of Shades avails me.

What is it?

What's a "Patch of Shades" and why should I care? Indeed! In the early 1980's, Emmett Chapman wanted a wah style effect to use with the instrument he invented in the 1970s, the Chapman Stick. He got together with a pedal designer (whose name I do not yet know - there's a story there, too), and came up with a very unique controller for this effect. It consisted of two pieces of magnetic tape, similar to the tape used to record records at the time, in close proximity to each other that the performer pressed on with a foot or shoe or toe. This varied the resistance of the circuit and altered the sound. The effect had three functions - wah, double wah, and envelope wah. Also designed into the unit were various inputs and outputs for effects loops, dry outs, aux inputs, etc. All in all, a cool-bomb of a stomp box. I believe I read somewhere that it was introduced at the 1982 NAMM show with much fanfare and excitement (but I can't find the original web page I found that on). As I retrieve stuff from my lost archives, I will post it here to try to be a repository for all Patch of Shades information. If you are one of those rare people who actually know about who designed and manufactured the pedal, and any other details about it, please email me or comment here. My next few posts will be about my adventures taking apart, repairing and successfully putting my own Patch of Shades back together.