This gadget was designed as part of etching and PCB design workshop at PIFcamp 2017 by Staš Vrenko and Vadim Vooku Petrov. During the workshop participants learned to design a circuit in KiCAD and later etched and built the board. In this instructable the etching process will be skipped (there are plenty on Instructables, check this one).
The circuit is based on the schematic of a classic APC, with two additional CV inputs, that you can connect to different CV sources (0 - 9 V) for example: Baby10 sequencer, 40106 oscillators, 4040 frequency dividers… We also tested the device with some “proper” synths, like Moog Werkstatt, and gained extended control over the sound.
Step 1: Parts List & Layout
1 x PCB (use the PCB Layout in the next step) + drill the holes (1mm drill (max) + 2,5 mm for the potentiometer mounting holes)
2 x IC 555 timer
2 x 8-pin IC holder
5 x 1K resistor
2 x 500K LIN pot
1 x 10nF ceramic capacitor
1 x 100nF ceramic capacitor
1 x 10uF electrolytic capacitor
1 x LED
1 x audio jack
1 x 9V battery clip or power adapter
socket Header pins (female or male)
2 x jumper wires for bridges (blue lines on the assembly manual)
NOTE: The PCB is designed for a specific potentiometer shape, but you can also wire up different ones.
Step 2: Circuit Layout for Etching
The dimension of the board is 40 x 50 mm, you can use a 100 x 160 mm Euro-standard PCB and make eight individual PCB from one.
Make sure you print out the proper size!
For drilling the holes use a 1mm drill (max) and a 2,5 mm for the potentiometer mounting holes.
Step 3: Use of Voltage Control Pins
The PIFAPC 9000 uses header pins (use male or female) located at the top of the PCB as two individual CV inputs, from 0 - 9V (max). You can connect them to different devices with a (header) jumper wire. To close the circuits the ground (one both devices) must be connected. There is also a ground connection on the PCB for that purpose.