Where Modulation Connects

FAC Polyflo is an AUv3 plugin for modulating and sequencing MIDI instruments and modular gear via control voltage. It outputs MIDI and analog CV simultaneously, making it well-suited for hybrid setups that combine digital and analog equipment.

The plugin includes two LFO generators offering 10 waveforms, including classic shapes and random spline, with support for cross-modulation and syncing. It also features an envelope follower that tracks audio FX input or an external sidechain. The generated signals, together with the host clock and MIDI input, are fed into six independent FLO(W) processors.

These processors combine, shape, and route inputs using math operations, conditional logic, and comparators. Each FLO includes individual polarity, division, and multiplication controls, providing deep and flexible modulation that balances chaotic creativity with precise timing.

Each FLO processor output is connected to its own output bus, enabling easy integration with hardware via DC-coupled audio interfaces like the Expert Sleepers ES-9. For simpler setups, FLO outputs can be routed to the stereo output. FAC Polyflo can also convert MIDI notes, pitch, and control changes into control voltages, making it a powerful MIDI-to-CV solution.

If you prefer to work exclusively with software, the plugin runs smoothly in software-only environments with full MIDI support, making it equally suited for purely digital workflows.

FAC Polyflo works as both an Audio Unit FX and MIDI FX, featuring a clean, touch-optimized interface with precise control and waveform visualization. It’s available as an AUv3 for iOS (iPad/iPhone), macOS, and Vision Pro, and requires a compatible AUv3 host app to run.

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ⒶⒷ LFO Generators A, B Waveform: Includes 6 classic waveforms (Sine, Triangle, Ramp Up, Ramp Down, Square, and Impulse) and 4 random spline-based shapes (Sine, Square, Bounce, and Stair). The spline waveforms can operate in two modes. In fixed mode, they emulate traditional LFO shapes. In random mode, each target point of the curve changes continuously, creating evolving and non-repetitive modulation patterns Dual Knob: Each waveform group has its own set of parameters. For the classic waveforms, the left knob adjusts phase offset, and the right knob controls the waveform shape. For spline waveforms, the left knob sets the amount of randomness, while the right knob adjusts the overall curve tension or shape Rate: The left toggle switches between host-synced and free-running mode. In sync mode, the right control sets the tempo-relative rate, for example, 1/4, 1/8, or 1/16 notes. In free mode, it sets the LFO frequency in Hertz
Ⓒ LFO Cross Modulation and Sync Routing Toggle: Enables one LFO to modulate or control the phase of the other one. Set to OFF to disable cross-modulation Dual Knob: The left knob sets the amount of frequency modulation, where the source LFO affects the speed of the target LFO. The right knob sets the amplitude modulation amount, controlling how much the source LFO affects the output intensity of the target Hard Sync: Forces the target LFO phase to reset at each zero-crossing of the source LFO, ensuring precise synchronization. The optional Smooth mode applies the source LFO's phasor as an amplitude window contour, softening transitions for more natural, fluid modulations	Ⓓ Envelope Follower Source Toggle: The envelope follower can track either the input signal of the audio FX or the sidechain signal (if provided by the host). Note: This option is unavailable in the MIDI FX extension Gain: Level of the envelope signal Dual Knob: Each knob defines the rate at which the envelope rises or falls The envelope follower is available in each FLO processor, either as a classic envelope for smooth, controlled modulation, or as a raw, untreated audio signal for more aggressive, unprocessed dynamic tracking
Ⓔ FLO Processors The six independent processors all have the same controls: ① Top Toggle: Displays the FLO's index number and an optional title. Tap to activate or mute the processor instantly ② Left Slider: Adjusts the output level of the processor. This controls the intensity of the signal being generated ③ Center Waveform: Displays a real-time visual representation of the processor’s output ④ Right Slider: Controls the offset of the processor’s output, enabling you to shift the range of modulation up or down. Use it in conjunction with the overflow parameter available on the right-bottom toggle ⑥ ⑤ Left Bottom Button: Provides a short summary of the sources and operations configured in the processor. Tap to reveal the floating inspector view, giving you access to advanced settings for deeper customization ⑥ Right Bottom Toggle: Provides context-specific (signal or gate) options. It includes overflow control with three options: limit, fold, or wrap signals to handle extreme signal ranges, and chance (stochastic gate) to introduce random variation to the gate/trigger signals MIDI Output: In the top-right of the center view, a MIDI button opens a pagesheet to set the global destination for all FLO MIDI outputs LEVELS: On the left side of the center view, you also have a global level control to set the level of all FLO processors at once MAIN CV: On the right side of the center view, there is a button that opens a popover, allowing you to activate the output of any FLO to the stereo output of the plugin. Select the FLO (1–6) you want to output to the Left channel and the FLO you want to output to the Right channel. This comes as a complement to the 6 output buses (multi-out). Ensure your outputs are routed to a DC audio interface in your host. See note below.
Ⓕ Host Transport Bar Play Sync Toggles the start/stop of the generators based on the host transport bar's play status, ensuring the generators are perfectly aligned with your project’s playback	Ⓖ Preset Button Ⓗ Info Button Preset manager (Tap or long press) Review the app, Tip Jar to support FAC, documentation...

Floating FLO Processors Inspector View: Tap the summary button Ⓔ⑥ on any FLO processor to reveal the floating inspector view. This gives you access to the following options, which help you create different modulation or sequence outputs using operations with either 1 or 2 operands: 9 Operations Single Signal Input, Create a gate from Input, Sum of two inputs, Subtract two inputs, Multiply two inputs, Average of two inputs, AND of two gated inputs, OR of two gated inputs, XOR of two gated inputs 18 Source Operands LFO A Output, LFO A Phazor, LFO A Clock, LFO B Output, LFO B Phazor, LFO B Clock, ENV Follower, ENV Follower Raw, HOST Phazor, HOST Clock, MIDI CC Input, MIDI Note Input, MIDI Pitch Input, FLO Outputs (All minus current) Operand Modifiers Polarity, Phase Inversion, Level, Threshold, Rate Divider/Multiplier. Some modifiers are only available for specific operands and operations, such as thresholds for the gate comparator Output Options: Gate: Trigger Rise, Trigger Fall, Trigger Both, Gate + Polarity, and Chance (Stochastic Gate) Signal: Limit, Fold, or Wrap Slew Limiter: Smooths fast signal changes for a softened modulation response. 5 positions: OFF, Fast, Medium, Slow, and Slowest Range: Defines the level of the processor output, either in volts or decibels. This helps to limit the modulation range and provides better control over depth and offset parameters. The default range is 5V or -6dB Display Unit Toggle: Display the voltage or percentage unit value for the depth and offset controls Name: Provides an optional name for the FLO processor MIDI Output Options: MIDI CC: Select the MIDI Control Change destination for the processor output MIDI NOTE: Select the MIDI Note destination for the processor output

MIDI DEVICES: If your host does not provide a MIDI output connection to the plugin you can use an external or virtual MIDI device. Connecting to these devices via a plugin may cause timing jitter and latency due to the way the host handles synchronization and routing. Reducing the audio buffer size (64 samples) may help minimize timing fluctuations. For best results, always use the host’s built-in MIDI output routing when available

MULTIPLE OUTPUTS: Each FLO processor sends its audio to a separate output bus, labeled FLO 01 to FLO 06. In total, Polyflo offers 6 outputs via multi-output buses and 2 via the main stereo output.

HOST ROUTING: The plugin sends audio through these additional output buses, but routing is entirely handled by the host. It’s up to the host to receive these buses and provide a way for you to route them to mixer tracks or audio interface outputs. Check your host’s documentation for specific instructions on working with AUv3 multi-output plugins. AUM on iOS and Ableton Live on macOS provide an easy way to route bus outputs to audio interface outputs.

WARNING: FAC Polyflo outputs Control Voltage (CV) signals, which are low-frequency or DC. Only route these signals to a DC-coupled audio interface (e.g., Expert Sleepers ES-9, UAD Apollo, MOTU... See the list of available DC-coupled interfaces). Do not connect the output signal to speakers or AC-coupled inputs, as this can damage your system or hearing. FAC Polyflo is not liable for any damage to your equipment or materials

As with all FAC products, the interface has a unique sober look and provides a great user experience. The value of each knob can be monitored at any time. The knobs are very responsive, natural and follow a specific curve according to the parameter type

Preset Management

FAC Polyflo also comes with factory presets to provide you a source of inspiration to satisfy your needs in any situation you might require

The preset button provides common management features: loading, organization, saving, importing and exporting. The left and right arrows allow fast navigation shortcuts among all the presets (factory + user), a short press on the center label provides a detailed list of all the available presets, select the one you want to work with. On the other hand a long touch (hold) provides contextual operation