Nota Operator

Nota Operator is a four-operator FM (frequency-modulation) synthesizer. Each operator is a sine-based oscillator; wiring one operator to modulate another’s pitch produces the bright, metallic and bell-like timbres FM is known for.

Template page

This is the exemplar device page — its structure (Overview → Interface → Parameters → Tips → See also) is the template every instrument and effect page follows. Swap the screenshot in and verify the parameter table against the build.

Overview

Four operators (labelled A–D) each produce a tone. An algorithm decides which operators you hear (carriers) and which modulate the pitch of another (modulators). Modulating a carrier with a higher-ratio operator adds harmonics; more modulation depth = brighter, harsher tone.

Signal flow, at a glance:

Operators (A–D) ─▶ Algorithm routing ─▶ Filter ─▶ Amp/output

Interface

The device card has a left tab-rail:

• OPS — the four operators as rows: waveform, frequency ratio, fine tune and level, alongside a live harmonic spectrum of the current patch.
• ALGO — the algorithm picker (drawn as routing sketches), the full routing diagram, and per-operator carrier/modulator envelopes.
• FILTER — a low-/high-/band-pass filter with an interactive response curve.

Parameters

Per operator (A–D):

Parameter	Range	What it does
Wave	sine …	Operator waveform.
Ratio	coarse	Frequency as a multiple of the played note.
Fine	±	Detune in cents around the ratio.
Level	0–1	Output (carrier) or modulation amount (modulator).
Attack Decay Sustain Release	ADSR	The operator’s amplitude envelope.

Global:

Parameter	Range	What it does
Algorithm	1–11	Which operators are carriers vs modulators.
Feedback	0–1	Self-modulation of the feedback operator — adds grit.
FM Depth	0–1	Master scaling of all modulation.
Filter Type	LP / HP / BP	Post filter shape.
Freq / Reso	—	Filter cutoff and resonance.
Glide	0–…	Portamento time between notes.
Vel → FM	0–1	How much note velocity opens up modulation.
Key → Level	±	Level tracking across the keyboard.
Mono	on/off	Monophonic mode with legato under glide.
Volume	0–1	Output level.

Tips & recipes

• Bell: two operators, a carrier modulated by an inharmonic ratio (e.g. 1 : 3.5), short-to-medium decay, no sustain.
• Bright pluck: high FM Depth with a fast modulator envelope so the brightness decays faster than the tone.
• Add movement with a touch of Feedback and a slow modulator envelope.

See also

• Nota Volt — virtual-analog synth, for subtractive tones.