EDDY

The panel

Black Silver

Click any knob, jack, button or the screen. Everything shown is at its default setting, with a sample loop on the screen. Eddy comes in two panels, silver and black: Rack picks one from its own dark-panel setting, and you can force either from the module's right-click menu.

How it works

Inside Eddy is a single loop of values, like a tape loop that holds numbers instead of sound. It is not eight sequences. Every output is a different place to listen to the same one.

• The loop is 2 to 64 values long (LENGTH), each one a voltage somewhere between the lowest and highest the outputs can reach. Eddy starts with a fresh random loop, different every time you add one to a patch.
• The head is the place the last STEP landed on. TAP 1 always reads it, so TAP 1 is the newest value.
• On each STEP the head moves on one place (forwards, unless you choose another direction). With a chance set by DRIFT, the value it lands on is pulled toward a new random value. Otherwise it is left alone, so the loop plays again exactly as before.
• The other seven taps read the places the head visited a few steps earlier. TAP 2 plays what TAP 1 played a few steps ago, TAP 3 what TAP 2 played, and so on. SPREAD sets how many steps apart they are.

Why it is interesting. With DRIFT at zero the loop is locked, and the eight taps are one pattern heard at eight different delays: a canon. Turn DRIFT up and the pattern slowly mutates as it circulates, and because the taps read it at different times they each catch it at a different stage of change. That is the eddy: one current, tapped many times.

The knobs

DRIFT: how often the loop changes

The chance, on each step, that the value landing at the head is changed. At 0% the loop never changes: it repeats exactly, for as long as you like. At 100% every step changes a value, so (with a large jump) there is no memory at all and every output is pure turbulence. In between is the useful part: a loop that mostly holds its shape but keeps quietly mutating. The default is 20%.

How far a change goes is a menu setting, Drift jump size. A change pulls the value toward a fresh random one by that share of the way. Gentle (10%) gives small nudges, so the loop slowly warps. Full (100%) replaces the value completely: occasional big leaps. The default is Medium (50%).

LENGTH: how long the loop is

From 2 to 64 steps, in whole steps (the knob snaps). The default is 16. Short loops repeat quickly and sound like riffs; long loops take longer to come round, so the taps feel less related. The screen draws exactly this many bars.

Shortening the loop does not throw anything away. The values past the end are kept, so lengthening it again brings the old pattern back.

SPREAD: how far apart the taps sit

SPREAD is proportional to LENGTH. At 0% the taps are one step apart: a tight canon, where the eight outputs are almost one shimmering voice. At 100% they are spaced evenly round the whole loop, LENGTH divided by eight steps apart, so the eight outputs are related but distinct. The default is 50%.

Below a LENGTH of 8 there is not room for eight different places, so the taps are one step apart and wrap round the loop: with a LENGTH of 4, TAP 5 plays the same as TAP 1.

Where each tap sits, counted in steps behind TAP 1:

Direction

By default the head walks forwards through the loop. DIR, the fourth knob, changes the way it travels, and it has a CV input, so a stepped source can change direction as the music goes. The loop itself is the same either way: only the order it is read in changes. The default is Forwards. The knob snaps to the fifteen directions below, the same fifteen, in the same order, as Shoal and Fluke: Forwards · Reverse · Pendulum · Random · Drunk · Pong · Tide · Shuffle · Pools · Stride · Gravity · Converge · Diverge · Skitter · Anchor. With CV, 0 V is Forwards and +10 V is Anchor, so each direction takes about 0.7 V.

The taps follow the head. Each tap plays the place the head was on a few steps ago, in whatever order it has been moving. So in every direction the eight taps play the same path, each a little later, and SPREAD still sets how much later. Changing direction does not move the head: it carries on from where it is, the other way. RST still goes back to the start of the direction's own cycle in every direction (the first place; the middle for Diverge; the first place of the order for Shuffle). DRIFT still changes the place the head has just landed on.

Step, Reset and Reseed

Still

STILL has a latching button and a gate input. While either is on the loop stops dead: STEP does nothing, so every tap holds its voltage and DRIFT cannot act. It is exact, and it stays that way for as long as you like. Let go and the loop carries on from where it was. The button lights, and the screen gets an amber outline, while Eddy is still. RST and RSD still work while Eddy is still.

The IN jack

Patch a voltage into IN and DRIFT stops pulling toward a random value: it pulls toward your voltage instead. Each time DRIFT changes a step, the value at the head moves toward whatever is at IN at that moment, by the Drift jump size (Full replaces it exactly with the incoming voltage). So the loop gradually absorbs a melody, an LFO or a sequencer that you feed in, and keeps it as it circulates. Unpatch IN and DRIFT goes back to random.

IN is read through the output range: a voltage inside the range comes out of the taps as itself, and a voltage outside it is held at the edge. With the default ±5 V range, IN accepts ±5 V. If Quantise is on the taps still snap to the scale. IN reads the first channel of a polyphonic cable.

Gate expander

Eddy Gates is a small module (4 HP) that gives each of Eddy's eight taps a gate output. The quickest way to add it is Eddy's right-click menu: Add gate expander on the right. You can also add it from the module browser, under Ormer Modular, and place it directly to the right of Eddy, touching it. There is nothing to patch between them: Eddy hands it the eight taps itself. Move it away and the gates go quiet.

Each gate is high (10 V) while its tap is above the threshold. The threshold is in volts, across Eddy's output range: with the default ±5 V the knob runs from −5 to +5 V and sits at 0 V in the middle, and if you choose another range the knob and its readout follow it, so the middle of the knob is always the middle of the range. Gates read the tap before quantising, so they never flicker between notes. With the toggle set to TRIG, each gate instead gives a short 1 ms trigger on every step that lands with its tap above the threshold, so you can choose between an open gate and a stream of triggers. A step where the tap is below the threshold fires nothing, and neither does a frozen Eddy (STILL): no steps, no triggers. A tap that holds the same value, as in a locked loop, still fires on every step.

Sample and hold

With a gate on a voice, a tap's pitch can still change when the gate does not, which you hear in the release of the note before. Right-click Eddy Gates and choose Sample and hold the taps to fix it at the source. Eddy's TAP outputs are then held by their own gates: TAP 1 by GATE 1, TAP 2 by GATE 2, and so on, and the polyphonic cables carry the held voltages too.

• Sample on the gate takes the tap's voltage as its gate rises (in TRIG mode, as each trigger fires) and holds it until then. The pitch changes only when a new note starts.
• Track while high follows the tap while its gate is high and holds the last voltage while it is low. Steps that stay above the threshold still change the pitch, but nothing changes during the gap or the release.
• Off (the default) sends the live taps.

The held voltages are the ones Eddy would have sent, so Quantise and the output range apply. The gates themselves are not affected. It only works while the expander is attached.

Ideas. Send GATE 1 to an envelope for an accent that follows the pitch pattern, and GATE 5 to a second voice. Raise THRS and the gates thin out, so the busy taps become sparse rhythms. In TRIG mode each gate is a clocked stream of triggers that thins out as you raise THRS, handy for drums.

Quantising

By default Eddy's outputs are raw CV, bipolar unless you choose a unipolar range: any voltage between the lowest and highest, for pitch, filters, panning, anything. Switch Quantise on (right-click menu) and every output snaps to the nearest note of a scale, at 1 V per octave, which turns Eddy into an evolving melody generator. Scale and Root in the same menu choose the notes. Quantise is off by default, and the scale is the same table Shoal uses.

Scales: Chromatic, Major, Natural minor, Harmonic minor, Dorian, Phrygian, Lydian, Mixolydian, Major pentatonic, Minor pentatonic, Blues, Hirajoshi and In-Sen. The default is Natural minor; Root is any of the twelve notes, and the default is C.

The output range matters here. The outputs swing 5 V either side of zero by default, which is ten octaves. For melodies you will usually want less: choose ±1 V for two octaves, or ±2 V for four, in the Output range menu. The five unipolar ranges (0 to 1, 2, 3, 5 or 10 V) keep every note at or above 0 V, which suits a bass line or an oscillator that tracks upwards from C.

Patching and CV

Eddy has no audio. It reads control voltages and puts out control voltages. Triggers and clocks are read as a rising edge above about 2 V, so any standard gate, trigger or clock works. Every input reads the first channel of a polyphonic cable only. The outputs are single-channel, unless you choose a polyphonic routing in the menu.

Ideas. Clock STEP from a clock divider and send TAP 1 to a pitch input with Quantise on. Send the other taps to filter cutoff, pan or a second voice to get related lines. Patch a slow LFO into the DRIFT CV so the pattern alternately holds and melts. Use RST from a bar-length pulse so the loop always begins in the same place.

Eddy keeps its loop, its position and all its settings in the patch, so a saved patch comes back playing the same pattern.

Right-click menu

Installing

Eddy is free through the VCV Library, for Mac (Apple Silicon or Intel), Windows and Linux.

1. Add Eddy to your account on its VCV Library page.
2. In Rack, log in from the Library menu and choose Library > Update all. Rack downloads Eddy and any other plugins you own.
3. Restart Rack if it asks you to, then add Eddy from the module browser, under Ormer Modular.

Eddy needs Rack 2.

Troubleshooting

Nothing moves.

Eddy has no clock of its own. Patch a clock or trigger into STEP. Check that STILL is off (its button is dark and nothing high is patched to its jack): while it is on, STEP does nothing.

The loop never changes.

DRIFT is at zero, STILL is on, or the jump size is very small. Turn DRIFT up, switch STILL off, or press RSD for a brand new loop.

The pattern never repeats.

DRIFT is high. At 100% with a Full jump size there is no memory at all. Turn DRIFT down: the lower it is, the longer the loop holds its shape.

Some of the taps give the same voltage.

With a LENGTH below 8 the taps wrap round the loop and meet each other (with 4 steps, TAP 5 is the same as TAP 1). Raise LENGTH, or raise SPREAD to move the taps apart.

The taps sound like one voice.

SPREAD is low, so the taps sit one step apart. Turn SPREAD up to space them evenly round the loop.

The first step after RST seems to repeat.

By design: a reset puts the loop on its first place, and the next STEP stays there, so a reset arriving with a clock plays the first step rather than skipping it.

The notes are not in the key I expect.

Check Scale and Root in the right-click menu, and that Quantise is on. Eddy sends 1 V per octave, so the oscillator needs 1 V/oct tracking. A tuning offset on the oscillator only transposes the notes.

The pitch range is far too big.

The outputs swing ±5 V by default, which is ten octaves. Choose a smaller Output range in the right-click menu.

A tap jack gives a polyphonic cable.

Poly output routing is on in the right-click menu: the last jack of each group (TAP 2, 4, 6 and 8 for Pairs; TAP 4 and 8 for Split; TAP 8 for All 8) carries its taps as one cable. The single jacks still work, so patch those instead, or set the routing to Off.

The pattern plays in a different order from before.

Check the DIR knob and its CV jack. Only the order the head moves in changes: the loop itself is the same.

Lengthening the loop brought back old values.

By design: shortening the loop keeps the values past its end, so lengthening it again returns them. Press RSD to replace them all.

DRIFT pulls the loop somewhere I did not expect.

Something is patched into IN, so DRIFT pulls toward that voltage instead of a random one. A steady voltage there pulls every changed step toward it. Unpatch IN to go back to random.

The gates do nothing.

Eddy Gates only works when it sits directly to the right of Eddy, touching it. Check the threshold too: at 100% no tap can be above it, and at 0% every tap is.

The panel won't change colour.

Use the module's right-click Panel menu. If it is set to Follow Rack setting, Rack's View > Use dark panels if available decides.

Specifications

Eddy's engine is original. It uses no third-party code. Eddy is closed-source and proprietary, and free to use.