Eigendrums

Yesterday I thought about a drum machine:

  • Sits on top of a Shruthi analog filter board (for those who are cheap, there would be a soopacheap filter board with just an output jack, an output amp and a simple 5V supply).
  • 3 sound channels (boom, ti, tchak)
  • 8-bit Sample playback (samples stored in the MCU flash)
  • 2 Step sequencer + 2 gated envelope routable to sample pitch, cutoff, resonance, VCA and CV 1/2 channels.
  • Programmed with 2 rows of 4 knobs (!)

Now about the programming method… This will be a radical departure from the x0x thing everybody is doing. Each knob will control the mixing amount of 8 basic drum patterns containing positive and negative velocities. We mix, we sum, and everything with a velocity below a threshold gets dropped. The 8 patterns assigned to each knobs are such that they provide the most efficient basis for representing drum patterns (hence the name). Several bases would be provided - each extracted from a corpora of tracks of a given genre. So it would be more like a “sculpture” / “subtractive” way of programming drum patterns than the “element by element” / “additive” way typical of x0x drum machines. I think this would be great for live transformation of patterns.

Worth exploring?

The Return of the Rhythm Box!

Ill buy one!

edit: now that i had a bit time thinking about that thing i must admit: this is genious.

sounds very interesting!

seems like fun!
count me in!

This is good idea.

I’d need to see a video of that in action before I’d buy one (I can’t quite visualise how the programming would work from the description) but it definitely seems like an experiment that’s worth doing.

Sounds madness.

Really liking the idea the the semi modular approach.

Klee meets drum machine… Nice!

Yes very interesting concept !
count me in of course :slight_smile:

i want it for the 25 of December :smiley:

does sound interesting :slight_smile:
count me in too!

Oh and a mode in which velocities are interpreted as probabilities :slight_smile:

go for it!
(please)

Please 4 sounds: Kick Snare Hithat closed, and hithat open I’ll start to build a pad controller with FSR immediatly!

@EATYone
Just Polychain 2 together :wink:

Maybe an eEprom for more sounds on the 3 Channels - or will there be a “Eigendrums L” a la RX21L . . . .?

lol i’ve got a RX21L and search for cheap and more comon RX21…Good tools for circuit bending it is :))))

certainly not an I2C one because it is so slow… No idea how fast we could go by playing several samples at the same time from an SPI eeprom (and not sure how to do the DAC/eeprom arbitration correctly). Played back from internal flash, with a 64k part split into 16k of code and 48k of data, this gives 21 100ms samples at 22kHz.

Hey EatyOne,

i owned a RX21L loooooong ago, alongside with a DX27S, TX81Z, HR16 and the glorious ATARI 520ST running Notator. Im a child of the 90s i guess…

I will buy it!

a - please make it swing to (mpc60 style)!

I love the “pattern morphing” and auto-generated pattern ideas.
This is the type of drum computer/sequencer I dream of.

I assume we’d have to have a Shruthi control board for this, but could this ever expand to a standalone drum machine add-on? Or is that what we’re talking about, here?

Maybe I should back-up: you’re thinking of having three Shruthi-generated (analog-style) sound-sources, plus a lo-fi sample channel, or will this be all-sampled coming from the MCP?
This would be amazing if the sound palette could be expanded to include 8-bit samples and analog (or FM) -style drum synthesis.

I’d take the sequencer concept as a standalone product. Add a couple more CV/Gate outs and you have a killer modular interface.