Minimal Drum Machines

Update: For DIY kit versions of these, check out the Andromeda Mk units at ericarcher.net/products
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I'm testing the definition of "drum machine" with these fun little prototypes. Only two chips (no microcontroller). One knob (tempo). One button (reset). Sixteen rhythm presets on a DIP switch. Light reactive circuits to bend the sound.

Even though the machines can play alone, they'd rather play in a group. Thats because each machine has an infrared transmitter and receiver. This lets them form a wireless network to play at the same tempo. The IR link is limited to about 12" and does not work under bright incandescent light. (the video was shot with compact fluorescent)

At the end of the video I show how interrupting the IR link affects the sound. In theory, many of these machines could be networked.

Both machines in the video share the same sequencer design. It is based on the CD4089 "binary rate multiplier". Their sounds are different though. The unit in the foreground uses a pair of bridged-T oscillators to make clave / rimshot / bongo sounds. The unit in the back generates filtered noise bursts with a classic "swing VCA" mechanism.

Once finalized the designs are intended for use in a fun educational workshop setting.

Stay tuned.

Category:

Howto & Style

Tags:

• minimal
• drum
• rhythm
• machine
• DIY
• sequencer
• synthesizer

[asnierkishcowboy]

there seems to be a reverb on the sounds!? is that made by the units?

[EA78751]

@asnierkishcowboy spring reverb from the guitar amp

[allin1e]

This is awesome. Great work with the 40xx chips! Really impressive in itself.

[EA78751]

@allin1e thanks. Since this video was made, I've released DIY kit versions of these. They're called Andromeda Mk-1, Mk-2, Mk-3, Mk-4. Available through my website. Cheers.

[synthmonger]

have ya tried making drum synths out of a 4069 or 4011 wired as inverters in linear mode? Can get some fun overdrive sounds using a couple gates.

[EA78751]

I havent tried making drum oscillators with linear mode CD4X. Have you seen any examples of that? Arent the chips power-hungry in that mode?

[MerlinFpunkt]

very impressive!

can you do a kind of live-set with some more of these little machines?

[fromtheinsides]

wow great work man



[crazyedd123]

that's pretty awesome. imagine using that at a gig, so whenever the lights flash or dim the drum beat changes with it.

it'd be cool to see something like this developed further, like heat reacitive circuits or moisture reactive circuits

[Svargiyasangita]

Awesomness! 

[SPEEDYDUSTREAM]

I Freakin' love that IR Network Idea. Top Notch

[athask8]

so what is your sitee?

[quadcam24v]

schematics by any chance?

[SoloDaniaveces]

que crack!!! jaja que wena