Plinky 4hp Expander (2 of 3, white/blue LEDs) - Black

The Plinky Expander is a 4 hp eurorack module which provides MIDI input and output (on TRS MIDI type A connections), a USB B port for MIDI, and four -5 to 5V CV outputs for the Plinky's LFOs (A, B, X, Y). If you plan on racking your Plinky, this is, in my opinion, a fairly essential accessory.

I built these expanders using PCBs ordered from JLCPCB, using the open source schematics and bill of materials found on the Plinky GitHub. The materials are sourced from Thonk (3.5mm jacks, some headers) and Mouser (everything else).

The modules are set up to be powered from the Plinky via a 16-pin ribbon cable (included). They can also be powered via a separate 10-pin ribbon connection. (I'm not sure why you would do this, but I figured additional flexibility never hurts.)

I did not solder the jumper that allows for the USB port to provide power to the Plinky and Expander, as this requires an additional modification of the Plinky PCB (that I cannot make), but if you are comfortable making that modification, connecting the jumper pads (JP 3 on the main PCB) should be easy.

Please note: installing the 16-pin ribbon to the Plinky requires disassembling the face plate of the Plinky and reassembling it once the ribbon cable is connected. This involves removing the knobs and nuts surrounding the jacks; there is no soldering or desoldering required. There is not enough clearance in the pass-through for the cable header to reach the appropriate terminal without first removing the face plate.

The modules use LEDs to provide visual feedback for the LFOs. Each expander has a different arrangement of LED colors; please, refer to the title of the post and pictures for the expander colors used in this listing. The first color is used for positive voltages; the second color is used for negative voltages.

I'm not a pro builder, but I've got a decent amount of experience.

Along with the ribbon cable, I will also include Befaco Knurlies for racking the expanders.