C[omp]ute

From: andrew cooke <andrew@...>

Date: Tue, 4 Aug 2026 09:42:01 -0400

I've just recorded a track with two voices, using Paraphonic mode on
the Neutron.  You can hear it at
https://soundcloud.com/andrew-cooke-4/unremitting-transfer-4

The process was a little frustrating, so I am writing this as a
reference that might help others.  The lessons learned were:

1 - Trust your ears.  If you listen to the linked track I think it's
pretty clearly two voices without any odd glitches.  It took a lot of
playing around to get that far and there were times when I was trying
to convince myself I had things working despite it not sounding quite
right.

2 - Configure Neutron explicitly.  I am using SuperCollider and the
code for this piece includes:

	~neutron.restoreDefaults.
        setParaphonic.   // must be done before key priority
	setSplitMode(57, true).
        setRetrigger(false).
        setKeyPriority(\low).
        setAssign(\modWheel).
	setOsc1Bypass.
        setOsc2Bypass.
	setOsc1Range(\eightFoot).
        setOsc2Range(\eightFoot).
        setVcfMode(\low).
	allNotesOff;

Pretty much all of these are Midi sysex calls that configure the
machine.  Since most are hidden this saves a lot of frustration.

3 - There's only so much Midi information you can expose/use.  You can
set each oscillator using note on/off, you can get some kind of
triggering associated with those notes, and you can send something
else (probably CC1 / mod wheel) to the assign output.  That's two
frequencies, one trigger, and one extra parameter.

In unremitting transfer 4 I used the extra parameter as a trigger for
the upper voice.

4 - Without keyboard split it's difficult to know what note will be on
what oscillator, which in turn makes it difficult to have two coherent
voices.  The corresponding restriction is that the two voices must
cover separate ranges.

5 - The implicit trigger (inferred from on/off notes) can either be on
every note, or only when you transition from 0 to 1 or more notes.
Either would have worked here, I think (upper voice could be triggered
from all notes, or lower voice from 0 to 1 each bar).  Then "assign"
can provide the other.

I am using lazy/legato triggering for the lower voice, which means
that the lower voice note must be on for all four upper voice notes
(or a later upper voice note retriggers the lower voice).

6 - Given the above you can configure an upper and a lower voice, each
with a separate envelope, using default routing for one and attenuator
1 for the other.  For the record, my patches are:

  osc mix -> oscilloscope (with osc mix this lets you check osc/voice
                           consistency)
  osc 1 (upper) -> att 1 in
  osc 2 (lower) -> vcf in
  (vcf -> overdrive -> vca w env 1 is normalled)
  assign -> env gate 2 (trigger upper voice env)
  env 2 -> att 1 cv (apply env to upper voice)
  att 1 -> att 2 in (use att 2 knob for relative level of upper voice)
  vca -> sum 2 a (lower voice)
  att 2 -> sum 2 b (upper voice)
  sum 2 -> delay in (apply delay to both)

lfo, noise and sample+hold are not used (although noise seems to bleed
through into overdrive if it's turned up).

7 - I don't understand why key priority is necessary in paraphonic
mode with a max of two notes on at any time, but it seems to affect
things!

Andrew