nb_pp new

nb_pp

Plaits Palette engines as nb voices for norns: the 96 synthesis models of Rubato Audio's Plaits firmware, four voices (palette 1 to palette 4), each polyphonic.

This is an early version. It has been tested on desktop norns and on a norns shield (Raspberry Pi 3, 32-bit).

Install

1. in matron, enter ;install https://github.com/vehka/nb_pp

2. Enable the mod in SYSTEM > MODS and restart.

3. Load any script. The mod offers to download the SuperCollider UGen it needs (0.4 MB): K3 installs it, then K3 again restarts norns. If you turn the offer down, it is still in SYSTEM > MODS > NB_PP (K3).

The download is a prebuilt UGen for 32-bit norns and shields (armv7l). On anything else (desktop norns, a 64-bit system) build it yourself. This needs cmake, a C++17 compiler and the SuperCollider plugin headers (or a SuperCollider source tree, given as SC_PATH=...); the script fetches the submodules:

~/dust/code/nb_pp/ugen/build.sh install

It compiles about 120 files, which takes a while on a norns. Restart afterwards.

Without the UGen the mod still loads; the voices are silent and the mod menu says so.

Playing

Pick palette 1..4 as the voice in any script that uses nb. The voice's params:

• style: poly, mono (one note that moves, with slew) or perc (every note is a short trigger, note length is ignored).
• model: the engine. The next four params are renamed after what the model does with them: harmonics, timbre, morph and the Palette's fourth macro (0.5 is the model's stock sound).
• decay, lpg color: the Plaits low-pass gate. A held note stays open; decay sets how it closes after release (or after the trigger, in perc). Drums and resonators have their own envelope and ignore it.
• stereo: models render a left/right pair instead of out/aux. aux mix blends the aux output in when stereo is off.
• amp, gain (into a soft clipper), pan, send a/b (for sixolet's fx mod).

Velocity is the Plaits level/accent: it opens the gate further and brighter. Turning a param changes sounding notes too.

Choosing engines

SYSTEM > MODS > NB_PP lists the models by family. Models turned off there are skipped when turning the model param.

• E2 scroll, E3 jump to the next family
• K3 toggle a model; on a family line, the whole family
• K2 back

The choice is saved in dust/data/nb_pp/prefs.data and applies to all four voices. Saved param sets are not affected: a pset that uses a model that is off still plays it.

Not here (yet)

The custom wavetables, wave terrains, chord tables and speech banks the Palette web builder makes; the Drift/Step randomizer; Sync In and through-zero FM; an attack time. Chiptune plays as a plain gated oscillator, without its own arpeggio envelope.

Development

• ugen/eurorack is the Palette source (a submodule of lylepmills/eurorack). ugen/pp_voice.h wraps one engine, ugen/PlaitsPalette.cpp is the UGen.
• After updating the submodule: python3 ugen/gen_engines.py (rewrites lib/engines.lua, keeping the order so saved params stay valid), then rebuild and reinstall the UGen. The Lua list and the UGen must come from the same submodule revision.
• The prebuilt UGen is a release asset (ugen-1), named in lib/mod.lua with its checksum. After rebuilding on a device: tar -czf PlaitsPalette-$(uname -m).tar.gz -C ugen/build PlaitsPalette.so, attach it to a new release (ugen-2) and update the URL and sha256.
• lib/deps.lua and lib/deps/ are a copy of norns-deps, which runs the install.
• ugen/build/pp_host_test plays every engine without SuperCollider and checks that it sounds, stays finite and falls silent after release.

License

MIT, see LICENSE. The Plaits Palette engines and Mutable Instruments' Plaits and stmlib code in ugen/eurorack are MIT licensed by their authors (Emilie Gillet, Lyle Mills / Rubato Audio and the Palette contributors); ugen/pp_voice.h is adapted from that repository's Seed3 voice.