808/909 DIY Kick Drums?

[Simon]

A friend showed me a small DIY project that was a box with 808 and 909 Kick
Drums, it had a few different tuning knobs for the 808 and 909 Kicks. It
was triggered by either CV or MIDI, I'm not sure.

Can someone point me in the direction of DIY 808 and 909 Kick Drum
schematics (and maybe other drums like snare, hh), so I can try it myself?

Thanks
Simon
Canberra
AUSTRALIA