Euclidean Patch

This patch uses Euclidean sequencing to randomly select different note sequences and to trigger all of the amplitude envelopes for the patch.
Euclidean sequencing allows you to generate complex polyrhythms with just a few simple turns of a knob. The sequence length and pattern density are the only controllable parameters of the sequencer. Four Casio CZ-inspired oscillators serve as the sound sources for this patch.

External Audio Path:
Main audio outputs are on channels 1 and 2.

Internal Audio Path:
• Four CZ oscillators are each routed to their own channel of a Shaped Dual Envelope VCA.
• The four synth voices are mixed together into a Valley Plateau reverb.
• Oscillators 1 and 2 are tuned a perfect fifth apart.
• Oscillators 3 and 4 are also tuned a perfect fifth apart and one octave above oscillators 1 and 2.
• The oscillator pairs (1+2 and 3+4) are hard-panned left and right and share the same channel on the mixer, creating a wide and unpredictable stereo image.

Internal CV Path:
• A master 8-step sequencer generates three channels of raw voltages, which are fed into two separate 4:1 sequential switches.
• The outputs of the switches are sent through an offset, attenuator, and quantizer, giving the user control over note offset and sequencer range.
• The switches are modulated by a Deviant module, which randomly selects between the sequences.
• Each sequence is routed to its own oscillator pair (1+2 and 3+4).
• Two cross-modulated LFOs control the waveshape and phase modulation of the CZ oscillators.
• A Euclidean sequencer triggers both channels of the Deviant, as well as all four amplitude envelopes for the oscillators.

MetaModule Knob Mappings:

Knob Set 1 (Macros):
A - Note density voice
1 B - Note density voice
2 C - Note density voice
3 D - Sequence length
1 E - Sequence length
2 F - Sequence length
3 U - Amplitude decay voice
1 V - Amplitude decay voice
2 W - Note offset sequence
1 X - Attenuator sequence
1 Y - Note offset sequence
2 Z - Attenuator sequence 2

Knob Set 2 (Mixer):
A - Volume
1 B - Pan
1 C - Volume
2 D - Pan
2 E - Reverb dry/wet
F - N/A
U - N/A
V - N/A
W - N/A
X - N/A
Y - N/A
Z - N/A


Euclidean.yml (19.4 KB)
Euclidean.vcv (4.6 KB)

2 Likes

Great patch- thanks!

This is a beautiful patch. The stereo and two-octave range give it a real sense of space, and the CZOsc sounds are so cool and make me want to play around with that module myself.

I might be misunderstanding something but the rhythms didn’t sound like Euclidean patterns to me, so I checked and it turns out that the Topograph that’s doing the trigger sequencing is not in Euclidean mode — it’s in “Henri” mode, in which it reads from the preset pattern map from the Grids firmware (but I think reads from it in a different way than Grids? the manual isn’t entirely clear).

You can switch it to Euclidean mode from the options menu, and that also sounds very nice but to me a bit more random and less composed. Or try “Olivier” mode for something sparser. The original Henri is definitely my favorite.

1 Like