These are great. They’re four modules – bass drum, snare, hi-hat and clap – based around an adaptation of Tom Whitwell’s (Music Thing Modular) Radio Music.
It’s synthesis rather than samples, and each module can morph between four sounds, including all the in-between stages, across X and Y axis under voltage control. There’s a software editor to program sounds via the SD card.
I got a partial kit from Thonk – they only do partial and full kits, no PCB/Panels alone, as they don’t distribute the firmware, so you have to have a pre-programmed Teensy on each module.
These were a very easy through-hole build (minus the single SMD voltage regulator, but nothing challenging there) with a handful of resistors and caps, and the only components in the BOM I had to order in were the 50k Pots and the DIP-8 MCP6002 op-amps (I fudged an SMD MCP6002 onto a DIP-8 adapter to test them while I was waiting for RS Components to deliver them).