A little over a month ago, we featured a project from [Igor] who built 64 bits of DRAM from scratch using discrete components. Jokes about memory pricing aside, he did have a use case for such a small amount of memory — he is using it in a custom-built drum machine. But featuring the memory build and not the drum machine was perhaps putting the cart before the horse, so in this video, [Igor] shows off the construction of each part of his impressive 16- or 64-step sequence drum machine.
This isn’t Igor’s first drum machine, either, although his previous build was a bit more limited. It had fewer steps in the sequence and didn’t quite have the range of his newer model. The upgraded version can play more steps but also includes force-sensitive drum pads based on piezo sensors and more voices (drums) as well. Each voice is built electronically using various op-amps and passive components, and [Igor] has the schematics for each of them, as well as every other part of the drum machine, for those looking to recreate any part of this on their own. There’s a lot going on in this lengthy video as well, so for the musically inclined, it’s worth taking a look in full.
Now that our horse is in the correct position in front of the cart, it’s worth going back and looking at the memory build if you missed it when it first ran. A small amount of memory makes the machine programmable rather than just playable, and truly expands the capabilities of a machine like this in the recording studio.
Is it named Grogu?
Somebody clearly used all the wires in their Radio Shack 150-in-1 kit as a kid.
Man, all those unlabeled, identically-sized blue buttons take me back. That thing reminds me of every stereo remote control from the early 1990s.
Hell yes. From experience, those piezo circuits are surprisingly hard to get right. Let alone everything else.
It would be nice if I could know how the few memory cells encode how force from the piezos are put into each beat. Three quarters of an hour is too much of my time. Some drum machines have an accent which is one more bit per note but a variable is the question. Generally drum machines are programed and not real time records from heads and sticks or pads.