Moln

norns
#1

Moln

Polyphonic subtractive synthesizer

IMG_3510

Moln is a script showcasing a rudimentary polyphonic synth built using the R engine.

Requirements

Norns with R engine installed in the ~/dust/code/r folder
MIDI device
Grid (64/128/256) (optional)
Arc (optional)

Documentation

moln

  • ENC1 adjusts main output level.
  • ENC2 changes filter cutoff.
  • ENC3 changes filter resonance.
  • KEY2 momentary toggles fine parameter control.
  • KEY3 triggers a random note.
  • MIDI device plays notes.
  • GRID plays notes too.
  • ARC changes filter cutoff (ENC1) and filter resonance (ENC2).

More parameters are available. Details in README

Note: Moln is built from general purpose R modules making it a performance intensive script. Polyphony has been lowered from 4 to 3 voices for v1.1.0 due to performance issues/CPU-spikyness. Initiatives have been taken to optimize the linux kernel used for norns. I expect to be able to raise polyphony again in the future (Polyphony is easily changed by editing a constant in the script).

Download

Moln v1.1.1
Github

20 Likes

Norns: R engine
#2

@jah i love your intense low-fi screen interfaces

6 Likes

#3

R engine has been moved from we repo to: https://github.com/antonhornquist/r

I’ve updated the Moln script which now assumes R engine is installed in ~/dust/code/r folder

3 Likes

#4

this is a great sounding engine!

1 Like

#5

tried this tonight, and love it!
sounds really good, and its very playable. :slight_smile:

1 Like

#6

Sounds awesome!
How are pitches laid out on Grid? It’s different that EarthSea and we’ll tuned to itself but I can’t figure it out.

1 Like

#7

Thanks.

For 16 columns wide grids this is used:


(this is from an addition by @ppqq to the old hello gong script)

For 8 columns wide:

which is the same but padded 4 cols to right.

I’m mostly using an external MIDI device (the OP-1) to play this script, though.

3 Likes

#8

I’m seeing ~ 15% CPU with a CM3+. I like the harmonics at high filter resonances.

0 Likes

#9

FYI. The CPU% reported in the norns UI is an average of all cores. Scsynth runs on one core and IIRC Moln used ~40% with 3 voice polyphony. The problematic bit, though, is CPU utilization spikes that cause xruns to happen, which is why I currently keep this script at a low default polyphony. These kinds of spikes occur due to various reasons. They have have in experimental tests been mitigated by @rick_monster ie. by changing linux cpu_governor to performance and lowering the priority for USB devices. These kinds of optimizations may end up in a future norns kernel, but it was too early to include them for norns 2.0.

0 Likes