This circuit is primarily based on a Harry Bissell design. I changed some values in order to make the input impedance 100k and I added a gate controlled switch, which I borrowed from the YuSynth portamento. The comparator circuit to control the LEDs which indicate the state of the portamento was my own design. This circuit allows you to adjust Attack slide separate from decay slide. It also allows you to adjust the portamento between linear slope and a slope resembling logarithmic.
above is the schematic. I know you are probably thinking, when is this guy gonna get a fucking scanner? I'm sorry, I'm broke right now.
I'm not gonna spend a lot of time how how to assemble this one. For me, I got lost somewhere along the assembly. It was just too complex and I had to rewire a bunch of connections I made. In the end, I can't remember what I got right and what I got wrong on my PCB labels. With 12 panel mounted knobs, 12 jacks, and 12 leds, it made for a lot of hook up wires. Below is the PCB without labels for hook up wires, to be amended at a later date.
So, I started etching aluminum with Copper Sulfate instead of Ferric Chloride. From what I've read, it's safer and better. I like it better too.
this is my class transfer griddle, I was attempting to make a nice transfer press out of it. It will eventually happen.
basically, you mix equal parts Copper Sulfate with table salt and add that to water. My solution was very strong because I basically mixed in as much as I could get to dissolve into the water.
This is a 2 bath system. Copper Sulfate on the left and just regular water on the right.
I believe what happens, is the copper and aluminum trade places. The copper leaves the copper sulfate mixture and solidifies, while the aluminum takes its place in the mixture, becoming Aluminum sulfate.