Noise, Clock/Random Pulse, S&H/T&H, and Slew/Envelope Follower

A veritable storm of activity

Flurry collects and connects a number of practical modular synthesis tools, focussed on clocks, noises, and randomness to create a module that is rife with opportunities for exploration and experimentation.  Equally capable as a synthesis source, modulator, clock, or signal modifier;  It is bound to find a way to bring new life and dimensions to your synth patches.    

In stock


Most people consider noise to be “undesirable,” and product developers expend great effort to design circuits that minimize noise. So why make a module designed specifically to create noise?

Indeed, unwanted noise is undesirable. But not all noise is unwanted. Synthesizing the sound of wind or waves are a couple of the more obvious uses for a noise generator, but the possibilities go far beyond. The crack of a snare hit; the breathiness of a flute sound; an added sizzle to a resonant pad — all are within the sonic domain of noise.


  • 16 digital noise types, each with 2 morph parameters, one with a modulation input.
  • A clock and random pulse source with adjustable and modulatable rate.
  • Accurate pink and white noise sources.
  • Analog sample & hold and track & hold circuits with very low droop.
  • Analog slew with adjustable slew time and edge selection (rising edge, falling edge, or both).
  • Analog envelope follower.

One of Flurry’s more interesting aspects is its collection of digital noise generators, which provide a wealth of interesting noises, suitable for either audio or modulation purposes. Each noise type has its own pair of unique parameters to further dial in the desired characteristics, with the primary parameter under CV control.

But noise has many other benefits beyond simply being heard. Noise happens to make a wonderful modulator. When noise is used to modulate a filter’s cutoff frequency, or an oscillator’s pitch or pulse width, then all sorts of raspy, buzzy, gritty timbres are obtained.

Noise is also a key ingredient in sample & hold circuits — a technique most commonly used to generate stepped, random voltages. The circuit works by sampling an input signal’s voltage each time you send it a clock pulse, and holding that voltage until the next clock pulse. So, naturally, Flurry also contains the requisite clocking tools! Two of the most common destinations for the S&H output are a filter’s cutoff frequency (creating stepped, clocked timbral changes), and oscillator pitch (which produces random notes at clocked intervals).

Of course, you might not always want your voltages to change so abruptly at each clock pulse. Maybe you’d prefer they wobble about gradually and with more grace? To do that, you need a slew circuit, and once again Flurry has you covered — allowing you to select not just the slew time, but also whether the slew is applied to rising voltages, falling voltages, or both. A flick of the switch, and that Slew circuit becomes an envelope follower, enabling Flurry to generate envelopes from input signals (syncing to drum hits are a common use).

With all these features, plus the ability to create random pulses, clock to external pulses, and perform more esoteric track & hold duties, Flurry is a noise lover’s toolbox.

16 Noise Types


FLASHESRainbowAll Noise Types accessible via the MORPH knobCycles through all the Noise Types across both banksAdjusts each Noise Type’s primary MORPH parameter
REDVinylPops, clicks and hissDensityHiss
ORANGEWindSynthetic wind FXFundamentalActivity rate
YELLOWDropletsRandom FM’d wavelets RateResonance
GREENFM Regen4 Op FM patch generatorRegen RateMax base freq
CYANFM DrumBank of FM drumsDrum Sound1Bitcrush amount
BLUECymbalCymbal NoiseTuning: ±2 octHPF
PURPLEBarber PolePhased white noiseRateQ & direction
MAGENTAShortwave Shortwave emulationCarrier frequencySquelch depth


FLASHESRainbowAll Noise Types accessible via the MORPH knobCycles through all Noise Types across both banksAdjusts each Noise Type’s primary MORPH parameter
REDAmp Hum/HissAmp hum with hissHum levelCycles2
ORANGELooped WhiteTunable white noise loopTuningBuffer length3
YELLOWParticleParticle generatorDensitySpread
GREENFM Noise3 Op FM noiseFundamentalFM Index
CYANPhreakbox Phone tone generator Tone4Phone distortion
BLUECymbal 2Alternate cymbal noisePulse Width5Fundamental
PURPLENoise ChorusChorused white noiseRateDepth
MAGENTAChaosChaotic noise generatorChaos AChaos B

Select your Bank by holding the NOISE TYPE button and turning the Morph Attenuverter to the – side for Bank 1 and the + side for Bank 2.

1 Selects from Kick, Snare, Hat, Cowbell and Cymbal as you rotate the knob.
2 Clockwise from noon = 60 cycle hum + peak filter freq | CCW from noon = 50 cycle hum + peak filter freq.
3 Buffer Length increases from 256-4096 as you turn the knob. Regenerates when fully clockwise.
4 From CCW>CW: Dial Tone > 1…9 > 0 > # > * > Busy Tone > Ring Tone > A > B > C > D > FSK_0 > FSK_1
5 Pulse Width ranges from 3% to 50%

Specs + Downloads

Power116mA @ +12V
30mA @ -12V
ManualManual (v1.1 / 2023.08.23)
Manual (v1.1 / 2023.04.27)
Manual (v1.0 / 2023.03.20)
FirmwareMac / Win (1.1.1)