Neptune Audio to CV/Gate Combi

Wednesday, August 25th, 2010 | 7:55 am and filed in Tutorials, Record.


Propellerheads Reason 5 and Record 1.5 are finally released, and one of the things that many fellow tweak heads are curious to try is the Neptune pitch correction device in Record 1.5. Among the general pitch quantization and voice synthesis features, Neptune has a pitch-to-cv feature and an envelope follower which correspond to the ‘pitch’ and ‘amplitude’ CV output jacks.

The envelope follower is fairly straightforward and the CV generated from this output tracks the levels of the audio signal being processed through Neptune. The Pitch CV output does not conform to the standard Note CV scaling, so connecting this directly to the Note CV inputs of Reason synthesizers does not work properly. The good news is that there is a work around to creating an audio to cv/gate.

The typical Note CV is a unipolar value that corresponds to the MIDI protocol with the lowest value being zero (C-2) and the highest being 127 (G8). Neptune’s Pitch CV output is bipolar with the zero value being in the middle of the MIDI scale. The Audio to CV-Gate combinator patch uses a Thor Polysonic synthesizer to convert the value to conform to the Note CV system.


The archive includes the combinator patch which must receive audio from a monophonic source. The Spider Splitter A outputs should be connected to synth or sampler Note CV inputs, and the spider splitter B outputs are the Gate CV outs. Also included in the archive is a .record session that demonstrates a vocal track driving a Malstrom, a Thor, and a Subtractor - Record 1.5 and Reason 5 are required.

Analog Pitch Follower

There is also a solution to convert audio signals to cv/gate signals without using a Thor synth, and this patch, called Analog Pitch Follower [Send FX] | peff.cmb, is included in the Record 1.5 Effects Bank refill. This combinator is located in the Effects \ Pitch Processing \ Special Effects directory, and it includes ID8 sound modules triggered by the Neptune Pitch and Amplitude CVs.

The easiest way to use this is to add it on the FX bus, then route a send from a vocal source on the FX sends. This patch can easily be modified with other synth and sampler devices by inserting them in the combinator sub-rack and routing the audio outputs to the Spider Merger inputs.

Usage Tips

These patches were both created using a microphone and my voice as the control signal. With the Thor version of the converter, one issue to deal with is the envelope follower sensitivity. I recommend gating the mic signal using the Record Main Mixer dynamics section. Set the Gate with a threshold around -20 dB FS, range to -40 dB, and Fast mode enabled. This will prevent subtle noises from accidentally triggering note events.

Polyphonic patches do not play well with these audio to cv/gate configurations, so either set the device to mono (on Thor), or set the polyphony to 1, or enable Legato (Malström). These measures will set the synth or sampler to work properly when driven by the audio to cv/gate configurations. For smoother pitch transitions, set the portamento to a fairly high value. The pitch gliding then creates a ‘theremin like’ feel, as you play the synth using your voice.

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