Engl Z5 Footswitch clone.

This has to have been my most difficult project so far and the one of the first i did. It was a big PITA but hey, at least i learned about JK flip-flops.

I'm sure if you're interested in this, you have come across the schematic from House of Engl Amps USA or whatever the site is called, well... it's wrong. And it's responsible for me wasting a lot of time with the first version of the footswitch, that i wont be posting here. It sucked but it was a learning tool.

Eventually what changed everything was a good friend letting me take apart a real Z5 footswitch that i photographed inside and outside and dissected to allow me to finally make my own copy.

This is the original PCB design, it's not properly scaled (the distance between leds and switches) but the connections are correct. There's a capacitor and the socket missing, those were on another small board on the socket itself, but you can figure that out from the schematic, it has everything there.

Once i had this i had to reverse engineer it back to the schematic:

IC2 is wrongly marked, it's a 74HCT109, pay attention to the T, because the 74HC109 wont work without modification to the circuit. I'll fix the schematic later.
The main difference between this and the schematic available on the net are the Zener diodes that in the other schematic are nowhere to be found.

Having this, and having no way to get or make such a big PCB, i had to make another layout:

There are a few components near LD7 and LD8, a couple of transistors and resistors, that are nothing more than a way to have two leds each for the Contour and Master A/B. I didn't use this possibility, i didn't even place those components, but if you use this schematic, pay attention that some of those holes might serve the function of connecting to the components, but also to continue the opposite track.

Here is the final result:




Now that i had the internals all working, the look was also important, so i used a technique used by some people (and by me this time) to transfer ink from a laser printer to circuit boards. I printed the design onto the back sheets of labels. They are very smooth and shinny, they don't let the toner stick to them but they are also make what's printed very fragile... After printing, use a clothes iron to transfer the design to the box:

And here it is completed, next to a few other pedals i'll post about later.