Joranalogue Flow 3
Auto-dynamic 2-pole state variable filter with self-modulating envelope follower
6 HP Eurorack module
Flow 3 is a 6 HP auto-dynamic 2-pole state-variable filter offering simultaneous lowpass, bandpass, and highpass outputs. Behind its compact panel sits a novel state-variable topology with core integrator saturation for a clean yet distinctive sound, plus an exceptionally smooth resonance that easily reaches self-oscillation — at which point temperature-compensated, precisely calibrated tracking turns it into a quadrature sine/cosine oscillator with tight 1 V/oct pitch tracking. The ace up Flow 3's sleeve is its auto-dynamic nature: a combined decay generator/envelope follower controls the filter frequency over an adjustable polarised range, letting it modulate itself from either external triggers or by following the input signal's amplitude envelope (or both simultaneously). This makes heavy-hitting analogue kick drum patches trivial, and the Linkwitz-Riley response at minimum resonance lets Flow 3 act as a clean dual-band spectrum splitter (crossover).
Features
- 2-pole state-variable filter topology with simultaneous LP2 / BP2 / HP2 outputs
- Core integrator saturation for clean yet distinctive analogue character
- Smooth resonance reaching self-oscillation
- Temperature-compensated 1 V/oct pitch tracking in oscillator mode
- Quadrature sine/cosine outputs at self-oscillation (HP2 = 0°, BP2 = 90°, LP2 = 180°)
- Initial filter frequency range 22 Hz to 22 kHz
- Frequency down to 22 mHz (45 s period) with negative Freq CV — voltage-controlled quadrature LFO
- Combined decay generator and envelope follower drives self-modulating filter behaviour
- Decay range 100 ms to 3 seconds, exponentially-decaying (convex) curve
- Two-stage envelope follower attack — slows on steady signals to reduce ripple, fast on transients
- Envelope output 0 to +12 V, independent of Range polariser setting
- Range polariser ±1 V/oct for positive or inverted envelope modulation depth
Controls & Jacks (14)
- Initial Freq — Sets the initial filter frequency prior to envelope modulation, from 22 Hz to 22 kHz. With negative CV applied to the Freq CV input, frequen
- Resonance — Controls a feedback path from the filter output back to the input, emphasising the filter frequency. Reaches self-oscillation at the top of
- Range — Polariser that sets the depth of envelope-driven frequency modulation. Centre is zero, full clockwise is +1 V/oct maximum, full counter-cloc
- Decay — Sets the decay slew rate of the combined decay generator / envelope follower from fast (bottom) to slow (top), with a 100 ms to 3 second ran
- Auto — Toggles the envelope follower function. When enabled, the signal input's amplitude envelope automatically modulates the filter frequency thr
- Freq CV — Exponential 1 V/oct frequency CV input. Accepts negative CV down to frequencies of 22 mHz (period ~45 seconds) for quadrature low-frequency
- Res CV — Resonance CV input. +5 V corresponds to maximum resonance.
- Decay CV — Decay rate CV input at approximately 1 V/oct. Each additional volt halves the decay time, allowing decay rates beyond the slider range.
- In — Signal input. DC-coupled to the filter; the connection to the envelope follower is AC-coupled (rejects below 16 Hz). Send triggers here to p
- Trig In — Trigger input that fires a +10 V peak envelope with fast 1 ms attack and adjustable decay. Schmitt trigger with +2 V low / +3 V high logic t
- Env Out — Output of the combined decay generator / envelope follower. Always positive, between 0 V and +12 V. Amplitude is independent of the Range kn
- LP2 — 2-pole lowpass output, -12 dB/octave above the cutoff frequency. Self-oscillates with a 180 degree phase shift.
- BP2 — 2-pole bandpass output, -6 dB/octave attenuation slope on either side of the filter frequency. Self-oscillates with a 90 degree phase shift
- HP2 — 2-pole highpass output, -12 dB/octave below the cutoff frequency. Self-oscillates with a 0 degree phase shift.
How-To Guides
- Bass Drum Synthesiser
- Auto-Dynamic Filter Sweep
- Quadrature Sine VCO
- Linkwitz-Riley Dual-Band Crossover
- Accented Resonant Pings
Explore the interactive Flow 3 panel on BleepDex — tap any control to learn what it does.
