This is a KiCad project for a clone of PAiA's discontinued midi2cv8 V/Hz daughterboard. It was designed from the same schematic as the original and is being shared with you under the kind permission of PAiA. When installed, the board looks like this:
At the moment, there are three bugs in the circuit design. I am only going to build one of these things, so it's unlikely that I'll fix them, so I figured that I would leave a note about it here. These three bugs are solved by adding the wires below and bridging pin 8 of the 4051 to ground with a blob of solder. The workarounds, when in-place, look like this:
In addition, if you're adding this V/Hz daughterboard to a midi2cv8 that is already configured for V/octave CV, you'll have to change resistor *R28 (a 5.6k ohm resistor should be there), and add a new resistor to #R32 on the midi2cv8 motherboard. This wasn't obvious to me and spent a couple days trying to figure it out, so I thought I'd mention it here as well. Here are the values from page 12 of the midi2cv8 manual:
Designation | Value | Color Code A-B-C |
---|---|---|
*R28 | 2700 | red-violet-red |
#R32 | 2700 | red-violet-red |
Also, if this is the first time you're etching a board, I highly recommend tearing out a glossy page from a magazine and printing onto it for your toner transfer. Also, don't bother with clothing irons. I use an unmodified Swingline 1000L laminator. Tape up the magazine paper so it doesn't slip around, then run it through the laminator a dozen times or so. If you do it right, you'll end up with a transfer looking like this:
To get a head start, rendered PDFs for the PCB and the silk screen can be found in the rendered/
directory. If you fancy it, you can transfer toner from the silkscreen PDF to the front of a single-layer PCB for a poor man's silkscreen. It actually works really good and looks really nice!
Enjoy!