Ferry Island Modular Four Seas

Name: Four Seas
Brand: Ferry Island Modular

Four-dimensional wavetable oscillator

26 HP Eurorack module

A four-dimensional Eurorack wavetable oscillator with four related outputs, three-dimensional wavetable navigation, independent wavetable and frequency spreading, oscillator modulation, synchronization, and audio- or LFO-rate operation.

Features

Four independent outputs are organized as two independently rate-selectable pairs.
Three-axis navigation through an 8×8×8 wavetable space.
Independent X, Y, and Z spread controls derive three additional wavetable positions from the main position.
Up to twelve selectable three-dimensional wavetable banks.
Eight ratio sets distribute the oscillator across four related pitches.
Audio Input 1 is normalled to Audio Input 2 when Audio Input 2 is unpatched.
Selectable smooth interpolation or stepped movement between wavetable positions.
Open-source firmware and support for user wavetables created with Harbor.

Controls & Jacks (51)

Output 3 Modulation Amount— Sets how strongly the signal from Audio Input 2 modulates the phase of output 3.
X Wavetable Spread— Offsets additional wavetable positions along the X axis so the four outputs can read related positions from the wavetable space.
X Position— Sets the base X coordinate within the 8×8×8 wavetable space and acts as an offset to incoming X-position CV.
Z Wavetable Spread— Offsets additional wavetable positions along the Z axis so the four outputs can read related positions from the wavetable space.
Y Position— Sets the base Y coordinate within the 8×8×8 wavetable space and acts as an offset to incoming Y-position CV.
Coarse Tune— Provides coarse tuning of the oscillator's main pitch.
Z Position— Sets the base Z coordinate within the 8×8×8 wavetable space and acts as an offset to incoming Z-position CV.
Frequency Spread— Sets bipolar frequency spread according to the selected ratio: counter-clockwise produces subharmonics, the center provides gentle detuning,
Output 1 Sync Type— Cycles synchronization of output 1 among hard reset, first-quarter soft reset, and flip or waveshape-reversal sync; its illumination indicat
Y Wavetable Spread— Offsets additional wavetable positions along the Y axis so the four outputs can read related positions from the wavetable space.
Audio Output 2— Sends oscillator 2 at audio rate or, when selected for its pair, at an LFO rate.
X Position CV Attenuverter— Bipolarly attenuates the signal at the X Position CV Input before it is added to X Position.
Audio Input 2— Accepts an audio signal for phase modulation of output 3; when unpatched, it receives the signal normalled from Audio Input 1.
Z Position CV Input— Adds a −8 V to +8 V control voltage to the Z-axis wavetable position.
Audio Output 3— Sends oscillator 3 at audio rate or, when selected for its pair, at an LFO rate.
Tuning Lock— Locks the coarse and fine tuning controls to prevent accidental pitch changes.
Audio Input 1— Accepts an audio signal for phase modulation of output 1 and is normalled to Audio Input 2 when that jack is unpatched.
Y Position CV Input— Adds a −8 V to +8 V control voltage to the Y-axis wavetable position.
Outputs 1–2 LFO Mode— Cycles outputs 1 and 2 through normal audio-rate, slow LFO, and glacial LFO frequency ranges.
Z Position CV Attenuverter— Bipolarly attenuates the signal at the Z Position CV Input before it is added to Z Position.
Sync Input 1— Receives a synchronization signal for output 1.
Frequency Spread Mode— Selects one of eight frequency-spread ratio sets: just intonation, normal harmonics or subharmonics, Pythagorean fifths, subharmonic superpa
Y Position CV Attenuverter— Bipolarly attenuates the signal at the Y Position CV Input before it is added to Y Position.
Audio Output 1— Sends oscillator 1 at audio rate or, when selected for its pair, at an LFO rate.
Output 1 Modulation Amount— Sets how strongly the signal from Audio Input 1 modulates the phase of output 1.
Wavetable Bank— Selects one of up to twelve three-dimensional wavetable banks.
Outputs 3–4 LFO Mode— Cycles outputs 3 and 4 through normal audio-rate, slow LFO, and glacial LFO frequency ranges.
Sync Input 3— Receives a synchronization signal for output 3.
Z Wavetable Spread CV Input— Adds a −8 V to +8 V control voltage to the Z-axis wavetable-position spread.
Linear FM Input— Accepts audio or CV for linear frequency modulation through the FM attenuverter; the expected range is −8 V to +8 V.
Output 3 Sync Type— Cycles synchronization of output 3 among hard reset, first-quarter soft reset, and flip or waveshape-reversal sync; its illumination indicat
Bank CV Input— Accepts control voltage that is added to the Wavetable Bank setting.
Y Wavetable Spread CV Input— Adds a −8 V to +8 V control voltage to the Y-axis wavetable-position spread.
X Position CV Input— Adds a −8 V to +8 V control voltage to the X-axis wavetable position.
X Wavetable Spread CV Input— Adds a −8 V to +8 V control voltage to the X-axis wavetable-position spread.
Audio Output 4— Sends oscillator 4 at audio rate or, when selected for its pair, at an LFO rate.
Frequency Spread CV Input— Accepts a −8 V to +8 V control voltage for frequency spread through the adjacent attenuverter.
Output 1 Oscillator Modulation— Cycles output 1 modulation among traditional thru-zero phase modulation, phase-distortion waveshaping, and fixed-point scalar-underflow or F
Output 3 Oscillator Modulation— Cycles output 3 modulation among traditional thru-zero phase modulation, phase-distortion waveshaping, and fixed-point scalar-underflow or F
V/Oct Input— Provides 1 V/octave pitch control over a ten-octave tracking range; the expected input range is −3 V to +7 V.
Linear FM Attenuverter— Bipolarly attenuates audio or CV from the Linear FM Input before it modulates oscillator pitch.
Fine Tune— Provides fine tuning of the oscillator's main pitch.
Wavetable Smoothing— Toggles interpolation between wavetable positions; enabled produces smooth morphing, while disabled produces stepped transitions. Bank chang
Frequency Spread CV Attenuverter— Bipolarly attenuates frequency-spread CV before it is added to the Frequency Spread setting.
X Position CV Level— Visualizes the resulting X-position CV contribution after attenuation.
Y Position CV Level— Visualizes the resulting Y-position CV contribution after attenuation.
Z Position CV Level— Visualizes the resulting Z-position CV contribution after attenuation.
X Wavetable Spread CV Level— Visualizes the X-axis wavetable-spread CV value added to the panel control.
Y Wavetable Spread CV Level— Visualizes the Y-axis wavetable-spread CV value added to the panel control.
Z Wavetable Spread CV Level— Visualizes the Z-axis wavetable-spread CV value added to the panel control.
Frequency Spread CV Level— Visualizes the attenuated frequency-spread CV added to the Frequency Spread setting.

How-To Guides

Build a playable wavetable voice

Explore the interactive Four Seas panel on BleepDex — tap any control to learn what it does.