Sound examples for the modular synthesizer

All 84 examples from the ModuloOne library to read, each with its note: what it shows, what to try with it and how it is built from modules and cables. First comes the beginner’s course, where you patch the cables yourself. “Open in the generator” loads an example onto the canvas, to listen to and build on.

Basic course

Twelve lessons where you patch the cables yourself. Part 1 goes in seven steps from the first tone through filter, envelope, sequencer and LFO to echo and reverb, each lesson starting with the solution of the previous one. Part 2 shows the remaining modules in five standalone lessons.

Lesson 1: A tone

Open in the generator Modules: Oscillator, Oscilloscope

New in this lesson

An oscillator produces a tone. You only hear it once a cable connects it to Main Out. The oscilloscope shows what its waveform looks like.

Tasks

If audio is still off, click “Start audio” at the top. Then drag from the oscillator’s output OUT to the input IN of Main Out (on a phone: tap OUT first, then IN). The cable is in place and a steady tone sounds.
Add a second cable from the same OUT to the oscilloscope’s IN. One output may feed as many inputs as you like.
Turn the frequency, then step through the waveforms. With “Pulse”, also turn the pulse width: the sound gets thinner and the pulse narrows on the oscilloscope.

If it stays silent

Is audio running (button at the top)? Is the cable plugged into IN of Main Out? Click a wrong cable to remove it.

In the library under “Basic course”: lesson 2 sends the tone through a filter.

Lesson 2: Filter

Open in the generator Modules: Oscillator, Noise, Filter, Oscilloscope

New in this lesson

A filter takes frequencies away from a sound. The lowpass lets the low ones through, so the sound gets darker. What lesson 1 produced is already patched; the filter and the noise are still free.

Tasks

Click the cable from the oscillator to Main Out to remove it. Then connect OUT of the oscillator to IN of the filter, and OUT of the filter to IN of Main Out.
Slowly turn the cutoff down: the sound gets darker. The oscilloscope still shows the sawtooth before the filter, Main Out the wave after it: it becomes rounder. Then set resonance to 10, and the cutoff whistles.
Noise instead of the oscillator: click the cable from the oscillator to the filter, connect OUT of the noise to IN of the filter. Through the lowpass it sounds like surf. Then set type bandpass, resonance 1, and slowly turn the cutoff: wind. It is quieter because only a narrow band gets through.

If it stays silent

Is there a cable into Main Out at the end of the chain? With the cutoff all the way down, the lowpass lets hardly anything through.

Lesson 3: notes with a beginning and an end.

Lesson 3: Envelope and VCA

Open in the generator Modules: Oscillator, Filter, Amplifier (VCA), Keyboard, Envelope (ADSR), Oscilloscope

New in this lesson

The keyboard gives the oscillator its pitch (NOTE). The tone still sounds without a break: the VCA lets it through as long as nothing is plugged into its MOD. An envelope opens and closes it on every key press.

Tasks

Connect GATE of the keyboard to START of the envelope, and MOD of the envelope to MOD of the VCA. Now it only sounds while a key is held (mouse or computer keyboard).
Attack to 1 s: the note swells. Sustain 0 and release 0.1 s: plucked. Release 2 s: it rings on.
Click the cable to the oscilloscope and patch it again from MOD of the envelope: while you play it shows the envelope’s shape. Finally, also connect MOD of the envelope to MOD of the filter: every note starts brighter.

How it works

GATE is open as long as the key is held. The envelope then rises (attack), falls to sustain (decay) and fades after you let go (release).

Lesson 4: the sequencer plays by itself.

Lesson 4: Sequencer

Open in the generator Modules: Oscillator, Filter, Amplifier (VCA), Step sequencer, Envelope (ADSR), Oscilloscope

New in this lesson

A step sequencer plays instead of the keyboard. It runs through its steps in tempo and sends NOTE and GATE on every active step. Envelope, VCA and filter are patched as at the end of lesson 3.

Tasks

Connect NOTE of the sequencer to IN of the oscillator, and GATE to START of the envelope.
Click steps to switch them on and off. Drag or use the mouse wheel over a step to change its pitch. Turn the BPM.
The scale is set to minor pentatonic: “Roll” invents new notes that fit together. Then set legato on and glide to 0.15 s: consecutive steps become one note that slides from pitch to pitch.

Tasks

Click the cable from the mixer to Main Out. Connect OUT of the mixer to IN of the reverb, and OUT of the reverb to IN of Main Out. Set the decay to 5 s: the small room becomes a hall.
Also connect GATE of the sequencer to TRIG of sample & hold, and MOD of sample & hold to MOD of the filter: every step sounds differently bright. Turn the range.
Save the patch under “My patches”. It stays in this browser.

Where to go from here

Use “Clear canvas” at the top and build your own, browse the library, or carry on with part 2 of the basic course: it shows modules that are still missing here.

Part 2, lesson 1: Distortion

Open in the generator Modules: Oscillator, Distortion, Oscilloscope

New in this lesson

Part 2 shows the modules the first part leaves out, each lesson with a small patch of its own. A distortion bends the wave, and every bend brings overtones. A sine shows this best because it has none itself. The oscilloscope “Osc” shows it before the distortion.

Tasks

Click the cable from the oscillator to Main Out to remove it. Then connect OUT of the oscillator to IN of the distortion, and OUT of the distortion to IN of Main Out and to IN of the oscilloscope “Dist”. Slowly turn drive to 100: in “Dist” the crests flatten, and step by step the sine turns into a square.
Click the display in Main Out until it says “Spectrum”. Set drive to 0: next to the tall peak of the fundamental there is only a small one. Back to 100: to the right of it a whole row grows, the overtones.
Set type to fold and slowly turn drive from 0 to 100: the crests first get a dent, then fold over several times, and a group of overtones stands as high as the fundamental. Then set type to steps, again from 0 to 100: the wave turns into a staircase that gets coarser and coarser. In the spectrum peaks appear that belong to no overtone, some even to the left of the fundamental.

How it works

Saturation squeezes the crests of the wave, fold folds them back, steps holds every value for a moment. The distortion evens out the loudness by itself. How strongly it acts also depends on how loud the sound arrives.

Part 2, lesson 2: the ring modulator multiplies two sounds.

Part 2, lesson 2: Ring modulator

Open in the generator Modules: Oscillator, Ring modulator, Oscilloscope

New in this lesson

The ring modulator multiplies two sounds. If the second one is very slow, only the volume of the first one wavers; if it is fast, new tones appear. You hear oscillator “A”. Oscillator “B” is set to 20 Hz and transposed down two octaves, so it swings five times per second.

Tasks

Click the cable from “A” to Main Out to remove it. Then connect OUT of “A” to A of the ring modulator, OUT of “B” to B, and OUT of the ring modulator to IN of Main Out and to IN of the oscilloscope. The tone flutters, and on the oscilloscope the wave swells and shrinks: ten times per second, twice per cycle of “B”.
Click the display in Main Out until it says “Spectrum”: one peak. Slowly turn transpose on “B” to 0: the flutter speeds up and turns into a buzz, and the peak splits. Then slowly turn frequency on “B” to 100: the two peaks move apart, and the buzz becomes two tones. The tone of “A” would lie in between; it is missing. Set amount on the ring modulator to 50: its peak is back. Return to 100.
Set waveform on “A” to sawtooth and frequency on “B” to 440: the spectrum shows an orderly row again, as for a single tone, and the oscilloscope shows a steady, repeating pattern. Then set frequency on “B” to 300: the peaks stand irregularly, the lowest far to the left, and on the oscilloscope nothing repeats any more, the picture stays restless. The tones no longer fit together; this is how bell and metal sounds are made.

How it works

“B” turns the volume of “A” up and down, through zero. When that happens fast enough, the ear hears two new tones instead of the tone of “A”: its frequency minus and plus that of “B”, here 220 − 100 = 120 Hz and 220 + 100 = 320 Hz. If “A” has overtones, each of them becomes such a pair.

If it stays silent

At amount 100 the ring modulator stays silent as long as nothing arrives at B.

Part 2, lesson 3: the mod mixer blends and shifts control signals.

Part 2, lesson 3: Mod mixer

Open in the generator Modules: Oscillator, Filter, LFO, Mod mixer, Oscilloscope

New in this lesson

In lesson 5 an LFO had one depth for all its targets. The mod mixer sits between source and target: it weakens a control signal, inverts it, shifts it and adds a second one. You hear a sawtooth behind a filter whose cutoff the LFO “Slow” pushes up and down.

Tasks

Click the cable from “Slow” to the filter to remove it. Then connect MOD of “Slow” to A of the mod mixer, and MOD of the mod mixer to MOD of the filter and to IN of the oscilloscope. It sounds as before, and the oscilloscope draws the curve of the LFO. Slowly turn amount A to 30: the curve flattens and the cutoff travels less far; the marker at the cutoff slider shows it. The depth on the LFO stays as it is. Return to 100.
Connect MOD of “Fast” to B of the mod mixer: a fast curve rides on the slow one, and the cutoff trembles as it travels. Set amount B to 100: the trembling is as wide as the travelling. Set it to 0: it is gone.
Set waveform on “Slow” to sawtooth: the curve rises steadily and drops with a jump. Set amount A to −100: it is upside down, the cutoff jumps up and sinks slowly. Set offset to 50: the whole curve moves up, and the cutoff stays higher. Set offset to 100: the curve is cut off at the top.

How it works

The mod mixer calculates amount A times signal A plus amount B times signal B plus offset. A negative amount inverts the signal. It puts out at most as much as a single source at full depth; whatever goes beyond is cut off. With a mod mixer in front of a target, that target gets its own strength, even if the same LFO is plugged in elsewhere too.

Part 2, lesson 4: the clock sets the tempo for sequencer and envelope.

Part 2, lesson 4: Clock

Open in the generator Modules: Oscillator, Filter, Amplifier (VCA), Step sequencer, Clock, Envelope (ADSR), Oscilloscope

New in this lesson

The clock is a timekeeper without notes: it sends a pulse on every sixteenth (CLOCK) and only every nth one at two dividers (÷A and ÷B). You hear the voice from lesson 4. The sequencer still runs on its own clock at 90 BPM, its GATE triggers the envelope; the oscilloscope draws it.

Tasks

Connect CLOCK of the clock to SYNC of the sequencer: the melody runs faster, at the clock’s 120 BPM. The BPM slider on the sequencer is greyed out, its tempo now comes from outside. Turn BPM on the clock, then back to 120.
Connect ÷A of the clock to SYNC; the new cable replaces the old one. The sequencer now advances only on every fourth sixteenth, that is in quarter notes, in step with the lamp on the clock. Divider A to ÷2: eighth notes. To ÷3: the notes change across the lamp. Back to ÷4.
Click the cable from GATE to the envelope, it disappears: silence. Then connect CLOCK of the clock to START of the envelope: it triggers on every sixteenth, each note of the melody sounds four times. Swing to 66: every second sixteenth comes later, the rhythm sways; in the oscilloscope the spikes move together in pairs.

How it works

A sequencer with a cable at SYNC advances one step on every pulse, an envelope triggers on every pulse. If several sequencers and envelopes hang on the same clock, they stay together, even when the tempo changes. ÷B works like ÷A; two different dividers against each other make a polyrhythm.

If it stays silent

Without a cable at START the envelope never triggers. It needs GATE of the sequencer there, or an output of the clock.

Part 2, lesson 5: randomness from the sequencer and from sample & hold.

Part 2, lesson 5: Randomness

Open in the generator Modules: Oscillator, Filter, Amplifier (VCA), Step sequencer, Envelope (ADSR), Sample & Hold, Oscilloscope

New in this lesson

Randomness comes from two sources here. The Random slider on the sequencer makes steps drop out. Sample & hold picks a random value on every pulse at TRIG and holds it until the next one; lesson 7 showed it on the filter. You hear the melody from the previous lesson.

Tasks

Random on the sequencer to 30: about every third note drops out, in a different place on every pass. The running light keeps going, on a dropped step it is dashed. To 100: silence. Back to 30.
Also connect GATE of the sequencer to TRIG of sample & hold, and MOD of sample & hold to MOD of the filter and to IN of the oscilloscope: every note sounds differently bright, the oscilloscope draws a staircase. When a note drops out, the stair stays where it is. Then click the cable at TRIG, it disappears, and connect CLOCK of the sequencer to TRIG: now every step brings a new stair, the dropped ones too.
Smooth to 0.1: the value no longer jumps, it runs to the new one in a curve. To 0.5: the staircase becomes a wandering line, the brightness sways gently. The swings have become smaller; Range to 100 makes them larger again.

How it works

GATE only sends a pulse when a note plays, CLOCK on every step. Sample & hold picks values between minus and plus Range; at the filter they push the cutoff down or up. With Smooth the value glides to the new one. If the next pulse comes before it gets there, it glides on from where it is.

Where to go from here

That was the last lesson of the basic course. Use “Clear canvas” at the top and build your own, or browse the library: every example has a note with things to try. “Random melody” and “Filter on the clock” show more randomness.

Interactive

Instruments to play on the computer keyboard or on the screen.

Harpsichord

Open in the generator Modules: Oscillator, Filter, Mixer, Amplifier (VCA), Reverb, Keyboard, Envelope (ADSR)

What it shows

A harpsichord in two octaves: its strings are plucked, not struck. That sounds thin, bright and pointed, and every note begins with a short pluck. Two registers can be switched on and off as on the real instrument.

The keyboard plays one note at a time and without touch sensitivity. That fits here: on a real harpsichord, too, every key sounds equally loud, no matter how hard you press.

Things to try

Press “Start audio” at the top, then play on your computer keyboard, ideally short, sparkling notes.
Set level B of the mixer to 0: only the 8′ register remains, the sound turns slimmer and quieter.
Set the cutoff of the lowpass to 800: this sounds like the lute stop, a strip of felt that damps the strings.
Set the cutoff of the highpass to 20: the body comes back, and the harpsichord sounds almost like a piano.
Set the decay of envelope “Filter” to 1: the pluck turns into a long wah.

How it works

NOTE goes to two sawtooth oscillators, one on the note and one an octave higher. The mixer combines them, the highpass makes them thin. GATE starts two envelopes: a very short one opens the lowpass for the pluck, the other lets the volume fade. Release is the damper when you let go.

Two registers

A harpsichord has several strings for each key; each row is called a register or choir. The names come from the organ: 8′ (eight foot) sounds at the pitch you play, 4′ one octave higher.

Here each register is a sawtooth, and the mixer is the stop: level A for 8′, level B for 4′. The 4′ is detuned by 4 cents, because two choirs of strings are never tuned exactly alike.

Since the harpsichord knows no touch sensitivity, adding registers used to be the way to play loud and soft: whole sections change their strength at once, which is called terraced dynamics.

Electric piano with tremolo

Open in the generator Modules: Oscillator, Amplifier (VCA), Reverb, LFO, Keyboard, Envelope (ADSR), Mod mixer

What it shows

An electric piano from the seventies: bell-like on the attack, soft as it fades, with the typical tremolo. The keyboard plays one note at a time and without touch sensitivity, so the strip stands in for your touch: the further right, the harder and more biting each note sounds.

Things to try

Press “Start audio” at the top, then play on your computer keyboard.
Strip all the way left: a gentle, round tone. All the way right: the notes bark on the attack.
Set the LFO’s depth to 0: the tremolo is off. Set its frequency to 7: it flutters.
Set the decay of envelope “Mod 1” to 1: the bite lingers longer.
Turn on “Hold”: notes keep ringing after you let go, as with the pedal down.

How it works

NOTE goes to two oscillators. The first bends the frequency of the second through its FM input, which makes the sound bell-like. Two VCAs in a row set how strongly: “Mod 1” with a short envelope, “Mod 2” with the strip. After oscillator “Carrier” come the VCAs “Amp” for the volume and “LFO” for the tremolo.

Touch and tremolo

On a real electric piano, the harder you strike a key, the brighter the note. Here the strip sets that: it is patched into the CV of VCA “Mod 2”. At 0 this VCA lets nothing through and a pure sine remains; at 1 you get the full bite.

The LFO makes the tremolo. It swings between −1 and +1; the mod mixer takes a quarter of that and adds three quarters on top. So the volume swings between half and full. Straight into the VCA, the LFO would also pull below zero, and the note would pulse twice as fast.

Grand piano

Open in the generator Modules: Oscillator, Filter, Mixer, Amplifier (VCA), Reverb, Keyboard, Envelope (ADSR)

What it shows

A concert grand across two octaves: every note is bright when struck and grows darker as it dies away. A second envelope that controls only the filter takes care of that. “Hold” on the keyboard is the sustain pedal. The keyboard plays one note at a time and without touch sensitivity, every key sounds equally loud.

Things to try

Press “Start audio” at the top, then play on your computer keyboard. Even a held note dies away, as on a real grand.
Tap a key briefly, once without and once with “Hold”: without, letting go damps the note; with it, the note rings out as if the pedal were down.
Set the decay of envelope “Filter” to 2: the note stays bright longer. At 0.2 it turns dull at once.
Lower the filter’s cutoff: the grand is now behind a curtain.
Set the reverb’s mix to 0: the hall is gone, leaving a dry studio.

How it works

NOTE goes to a sawtooth and a triangle, the mixer combines them. GATE starts two envelopes, one at the VCA for the volume and one at the filter for the tone color. Both have sustain 0, so a note dies away even while the key is held; release sets how quickly the damper stops it when you let go.

Why the note grows darker

A struck string vibrates in many overtones at once. The high ones lose their strength faster than the fundamental, which is why a piano note sounds bright and brilliant at first and then rounder and rounder.

Here envelope “Filter” does this: on the stroke it opens the filter to almost 2 kHz and closes it to 1 kHz within 0.8 s. Envelope “Amp” takes 2 s to let the volume fall. With a single envelope for both, the note would get quieter evenly, but not darker.

Für Elise, tap along

Open in the generator Modules: Oscillator, Filter, Amplifier (VCA), Step sequencer, Keyboard, Envelope (ADSR)

What it shows

The notes of “Für Elise” are stored in the sequencer, the rhythm is up to you: each key press fetches the next note. It does not matter which key.

Things to try

Press “Start audio” at the top, then tap one key of your computer keyboard in the rhythm of the tune. The running light in the sequencer shows where you are.
Alternate between two keys and press the next one before letting go of the previous one: the swaying figure E–D♯–E is tied, the envelope does not strike again.
Hold a key for a long time: the note keeps sounding softly until you let go.
Change the BPM of the sequencer: nothing changes, the tempo comes from the keyboard.
Set the octave of the sequencer’s root note from 4 to 5: the same tune, an octave higher.

How it works

The keyboard’s GATE goes to two destinations: to the envelope, which opens the note as long as the key is held, and to the sequencer’s SYNC. Each key press moves it on by one step; its own clock rests. The sequencer’s NOTE sets the pitch, the keyboard’s NOTE stays unused. All 32 steps are switched on, because an empty step would only repeat the previous note when tapped. To make the theme fit, the second swaying figure lacks its upbeat.

Glockenspiel

Open in the generator Modules: Oscillator, Ring modulator, Amplifier (VCA), Reverb, Keyboard, Envelope (ADSR)

What it shows

A glockenspiel made of metal bars: bright and clear when struck, then a long, pure ring. It plays two octaves high, from C5 up. “Hold” is on, because a struck bar rings out freely no matter how long you press the key. The keyboard plays one note at a time and without touch sensitivity.

Things to try

Press “Start audio” at the top, then play on your computer keyboard, ideally with short taps.
Turn “Hold” off: now letting go damps the bar, like a hand gripping it.
Set the ring modulator’s amount to 0: a pure sine remains, more flute than metal. At 100 the fundamental disappears and the sound turns crooked.
Change the transpose on oscillator “B”: the glockenspiel becomes a cowbell, a gong or a toy.
Set the decay of envelope “B” to 2.5: the metal rings as long as the fundamental.

How it works

NOTE goes to two oscillators; the second is tuned almost four octaves higher. The ring modulator combines the two into the metallic overtones. Two envelopes share the work: the short one lets the overtones fade, the long one the whole note.

Why it sounds like metal

A string vibrates in whole-number multiples of its fundamental, which sounds harmonic. A metal bar does not: its strongest overtone lies at 2.76 times the fundamental, and we hear that as metal.

The ring modulator multiplies two notes. What comes out is their sum and their difference. Oscillator “B” sits at 3.76 times the fundamental, so the difference lands exactly at 2.76 times, the sum at 4.76 times. At amount 50, half of the fundamental remains.

VCA “B” before the ring modulator lets the overtones fade in just under half a second; after that almost only the fundamental is left. A real bar sounds the same way: bright at first, then pure.

Jazz organ

Open in the generator Modules: Oscillator, Mixer, Amplifier (VCA), Distortion, LFO, Keyboard, Envelope (ADSR), Mod mixer

What it shows

A jazz organ in the style of the Hammond: three sine tones as drawbars, the percussion on the attack, a slight shimmer as from a rotating speaker and the modulation strip as expression pedal. A distortion at the end roughens it like an overdriven amplifier. The keyboard plays one note at a time, chords are not possible.

Things to try

Press “Start audio” at the top, then play on your computer keyboard. Play the keys connected: the percussion sounds only on the first note.
Drag the strip to the left: the organ gets quieter as with the expression pedal. All the way left, some sound remains.
Change the levels of the two mixers: they are the drawbars (see the note “Drawbars”).
Set the base level of VCA “Perc” to 0: the attack loses its “click”. Set the decay of envelope “Perc” to 1: the slow percussion.
Set the LFO depth to 0: the shimmer disappears. Frequency at 0.8: the slowly rotating speaker.
Set drive on the distortion to 0: the organ without distortion, made of pure sine tones.
Set drive on the distortion to 100: the organ turns brighter and rougher.

How it works

NOTE goes to four oscillators, each transposed differently. The mixers add up three of them. The fourth runs through a VCA of its own whose envelope has no sustain: it sounds only briefly on the attack, and that is the percussion. Envelope “Amp” starts without swelling and ends almost at once, like an organ. The LFO moves the pitch of all four a little. After VCA “Amp” the distortion (saturation, drive 40) squeezes the peaks of the wave flat. That gives the pure sine tones new overtones. Through the mod mixer, the strip sets the volume at Main Out; its offset keeps it from vanishing completely.

Drawbars

Mixer 1: A is 16′ (an octave lower), B is 8′ (the fundamental). Mixer 2: A brings both together, B is 5⅓′ (the fifth above). The percussion is 2⅔′ (an octave and a fifth above).

All three at full gives the jazz setting “888”. 8′ alone sounds like a flute; without 16′ the tone gets thinner.

Church organ

Open in the generator Modules: Oscillator, Filter, Mixer, Amplifier (VCA), Reverb, Keyboard, Envelope (ADSR), Mod mixer

What it shows

A church organ to play yourself: three stops, a large church as reverb and the modulation strip as expression pedal. The keyboard plays one note at a time, chords are not possible; the fullness comes from the reverb.

Things to try

Press “Start audio” at the top, then play on your computer keyboard. After you let go, the room rings on for seconds.
Drag the strip to the left: the organ gets quieter as with the expression pedal. All the way left, some sound remains.
Change the levels of the two mixers: they are the stops (see the note “Stops”).
Set the reverb’s mix to 0: this is how the organ would sound without the church.
Turn the filter’s cutoff up: the pipes sound sharper.

How it works

NOTE goes to all three oscillators, each transposed differently. The mixers add them up, the filter takes the edge off the square waves. The envelope lets every note swell briefly, like a pipe starting to speak. Through the mod mixer, the strip sets the volume at Main Out; its offset keeps it from vanishing completely.

Stops

Mixer 1: A is the 16′ subbass (an octave lower, a soft triangle), B is the 8′ principal (the fundamental). Mixer 2: A brings both together, B is the 4′ octave (an octave higher).

8′ alone sounds plain, with 4′ brighter and stronger, with 16′ fuller in the bass – like pulling the stops.

Play it yourself

Open in the generator Modules: Oscillator, Filter, Amplifier (VCA), Keyboard, Envelope (ADSR), Sample & Hold

What it shows

A simple synthesizer to play yourself: keyboard, oscillator, filter, VCA and one envelope. On top, Sample & Hold rolls a slightly different brightness for every keystroke.

Things to try

Press “Start audio” at the top, then click the keys or play on your computer keyboard (the layout is shown below the keys).
Change the waveform: sawtooth sounds bright, sine soft.
Turn the filter’s cutoff and resonance.
Lengthen attack and release: notes swell in and ring on.
Play keys connected (legato): only the first stroke restarts the envelope.

How it works

NOTE sets the oscillator’s pitch, GATE holds the envelope open while a key is down. The sound runs through filter and VCA to Main Out.

One output, two destinations

The envelope opens the VCA (volume) and the filter (brightness) at the same time: every note starts loud and bright and grows darker while held.

To hear it: click the cable from the envelope to the filter’s CV and it disappears. The notes then no longer grow darker while held.

Every keystroke different

The keyboard’s GATE also triggers Sample & Hold. On every keystroke it holds a new random value that shifts the cutoff by up to 590 Hz: the same note sounds duller one time, brighter the next. At the filter’s CV it adds to the envelope. Even played connected, every key rolls anew, although the envelope does not restart.

To hear it: set the range on the Sample & Hold to 0, and all keystrokes sound alike again. At 100 the difference gets large.

Synth bass

Open in the generator Modules: Oscillator, Filter, Mixer, Amplifier (VCA), Distortion, Keyboard, Envelope (ADSR), Mod mixer

What it shows

A bass from the analog synthesizer: round at the bottom, with a squelchy filter on the attack. A distortion at the end roughens it. It plays one octave low, from C2. The strip is a pitch bend: it pulls the note up or down by up to a whole tone and springs back when you let go. The keyboard plays one note at a time and without touch sensitivity.

Things to try

Press “Start audio” at the top, then play on your computer keyboard.
Play legato: glide lets the notes slide into each other, and the envelopes do not restart.
Hold a note and drag the strip, then let go.
Set the filter’s resonance to 15: the attack quacks like an acid bass.
Set level B of the mixer to 0: the sub drops out and the bass turns thin.
Set amount A of the mod mixer to 100: the strip bends a whole octave.
Set drive on the distortion to 0: the bass without distortion, cleaner and quieter.
Set drive on the distortion to 100: the bass turns brighter and rougher.

How it works

NOTE goes to two oscillators: a sawtooth on the note, a square one octave lower. The mixer combines them, the filter darkens them. The short envelope “Filter” opens the filter on every attack, “Amp” sets the volume at the VCA. After the VCA the distortion (saturation, drive 60) squeezes the peaks of the wave flat. That adds new overtones that the filter can no longer remove.

Pitch bend with the strip

The strip is set to ±1: the middle is 0, left −1, right +1. “Spring back” is on, so it jumps to the middle when you let go.

At IN of an oscillator, ±1 would already be a whole octave. The mod mixer takes 17 % of it, a little over two semitones, as far as the wheel on many synthesizers.

Both oscillators hang on the same mixer, so saw and sub bend together and do not drift out of tune against each other.

Vibrato by hand

Open in the generator Modules: Oscillator, Filter, Amplifier (VCA), Reverb, LFO, Keyboard, Envelope (ADSR), Oscilloscope

What it shows

A solo sound played with the keyboard’s modulation strip: the further right the strip stands, the stronger the vibrato and the brighter the sound.

Things to try

Press “Start audio” at the top, then play on your computer keyboard and drag the strip with the mouse.
Hold a note and slowly move the strip to the right: the vibrato grows like a violin’s.
Turn Spring back on: vibrato and brightness last only while the strip is held.
Lengthen Glide: the notes slide into each other.
Change the LFO frequency: the vibrato gets faster or slower. Depth limits its strength.

How it works

The keyboard gives the oscillator its pitch (NOTE) and opens the envelope (GATE). The LFO swings all the time, but only the strip at its DEPTH input lets it act: at 0 no vibrato, at 1 as much as the Depth control allows. The oscilloscope shows the LFO after the strip.

One strip, two destinations

The strip’s MOD output goes to the LFO’s DEPTH (vibrato) and to the filter’s CV (brightness).

To hear them separately: click a cable and it disappears. Ctrl+Z brings it back.

Honky-tonk piano

Open in the generator Modules: Oscillator, Filter, Mixer, Amplifier (VCA), Reverb, Keyboard, Envelope (ADSR), Mod mixer

What it shows

An out-of-tune saloon piano as in a Western: every note comes from three oscillators, just as a piano key strikes three strings. The strings are no longer in tune with each other, and their beating makes the wobbly “honky-tonk” sound. The keyboard plays one note at a time and without touch sensitivity, every key sounds equally loud.

Things to try

Press “Start audio” at the top, then play on your computer keyboard. A held note first drops quickly and then rings on quietly; when you let go, it stops.
Drag the strip all the way to the left: the piano is freshly tuned. To the right it gets more and more out of tune.
Set the envelope’s sustain to 0: held notes die away completely.
Lower the filter’s cutoff and turn the resonance back: the old saloon piano becomes a soft one.
Raise the reverb’s mix: the saloon becomes a large dance hall.

How it works

NOTE goes to all three oscillators. Through one mod mixer each, “1” and “3” also get a small part of the strip, one upwards, one downwards (share +2 and −2 %), up to 24 cents. The envelope opens VCA and filter on the stroke and quickly closes them down to a remainder: every note starts bright and loud and rings on darker and quieter.

Beating

Two notes of almost the same pitch alternately reinforce and cancel each other: the volume pulses. At A4 with 14 cents apart, almost four times a second, faster higher up. With three strings, three pairs beat at once, the outer pair twice as fast – hence the restless wobble.

Mixer “Submix” for bass drum and hi-hat (hi-hat at level 55, a little to the right with pan R 30) forms a subgroup. Its output goes to B of the mixer before Main Out; A gets the snare from the reverb.

To hear it: set level B of that mixer to 0, and only the snare remains. One control turns bass drum and hi-hat down together, their balance stays the same.

Four on the Floor

Open in the generator Modules: Oscillator, Noise, Filter, Mixer, Amplifier (VCA), Distortion, Step sequencer, Envelope (ADSR)

What it shows

A drum kit made only of an oscillator, noise and envelopes: bass drum and hi-hat, each with its own sequencer. The bass drum on every quarter note gives the pattern its name; a distortion folds its wave and gives the hit overtones. With snare, reverb and two mixers it is next to it as “Drum Kit”.

Things to try

Click the cable from envelope “Kick” to the oscillator to remove it: the pitch no longer falls, and the bass drum loses its punch.
Set drive on the distortion to 0: the bass drum without distortion, just the low sine.
Set drive on the distortion to 100: the sine folds over several times, and the hit turns bright and sharp.
Set type on the distortion to saturation: the peaks are squeezed flat instead of folded over, as in the “Drum Kit”.
Set the decay of envelope “Hi-Hat” to 0.2: the closed hi-hat becomes an open one.
In sequencer “Hi-Hat”, switch off all steps except 3 and 7: the hi-hat sits between the bass drum hits, and the rhythm starts to swing back and forth.

How it works

Bass drum: a sine at 55 Hz runs through a VCA. Its envelope (decay 0.09 s, sustain 0) is patched to two targets: at the oscillator’s IN it raises the note by an octave to 110 Hz on every hit and lets it fall to 55 Hz within 90 ms, at the VCA it turns it into a short hit. The falling pitch gives the bass drum its punch. After the VCA the distortion (fold, drive 60) folds the sine: while the hit is loud its peaks fold over and overtones appear, in the tail the pure sine remains. Hi-hat: of the white noise, a highpass at 6000 Hz lets only the hiss through, and an envelope with 40 ms decay switches it. Both sequencers run at 120 BPM with eight steps, the bass drum on every quarter note, the hi-hat on the sixteenths in between: it pauses on the bass drum beats, together the two would be too loud. The mixer combines both, the hi-hat at level 70 and a little to the right (pan R 30).

Gated snare

Open in the generator Modules: Noise, Filter, Amplifier (VCA), Reverb, Step sequencer, Envelope (ADSR)

What it shows

The drum sound of the 80s: a snare in a large reverb that a gate cuts off hard (gated reverb).

Things to try

Set the release of envelope “Gate” (at the VCA after the reverb) from 0.03 to 1: the gate closes slowly, and the reverb dies away naturally.
Set the gate length to 50 %: the gate closes earlier, and only a short hiss is left of the reverb.
Set the reverb’s mix to 0: only the dry snare, louder but short and thin. It is the cut-off room that makes the sound.

How it works

White noise through a highpass at 900 Hz, plus a short envelope (decay 0.2 s) at VCA “Snare”: that is the snare. It runs into a reverb with 2.5 s decay and mix 70 %. Behind it sits VCA “Gate” as the gate. Its envelope is set to sustain 1: it opens fully while the sequencer gate is open and closes within 30 ms afterwards. Both envelopes hang on the same gate. On beats 2 and 4, legato ties two steps each, and the gate stays open for 0.31 s. For the single hits a sixteenth before 3 and 1 it closes after only 0.16 s, so the cut can be heard by comparison.

Cowbell (808)

Open in the generator Modules: Oscillator, Filter, Ring modulator, Amplifier (VCA), Step sequencer, Envelope (ADSR)

What it shows

A cowbell modelled on the TR-808: two square waves whose product sounds metallic.

Things to try

Set the amount of the ring modulator to 0: only the square wave at 540 Hz, a plain beep.
Set the amount to 100: pure ring modulation, the root is missing, and the sound turns hollow and tinny.
Set the cutoff of the filter to 2600: the band-pass moves up to the high partials, and the bell gets brighter.

How it works

Two square waves at 540 and 800 Hz, the frequencies of the 808. The 808 mixes the two; here the ring modulator multiplies them at 70 %. This creates the sum (1340 Hz) and the difference (260 Hz) with their overtones, which are not harmonically related: the metallic ring. The remaining 30 % let the 540 Hz square wave through dry and keep the root. As on the 808, a band-pass shapes the sound: around 1000 Hz it lets the sum and the root through and damps the drone of the difference and the high partials. The envelope (decay 0.25 s) at the VCA turns the steady tone into single hits, seven in 16 steps.

Phasing (after Steve Reich)

Open in the generator Modules: Oscillator, Mixer, Amplifier (VCA), Step sequencer, Envelope (ADSR)

What it shows

Two voices play the same pattern, one slightly faster. They slowly drift apart and come back together after 20 s, and new rhythms keep appearing in between.

Things to try

Set the BPM on sequencer “B” from 126 to 120: both run in step, and the pattern stands still.
Set the same sequencer to 121: the voices move apart by only one sixteenth every 15 s.
Set pan A and B of the mixer to M: both voices come from the centre, and the drifting apart is harder to follow.
Set the transpose on oscillator “B” from 7 to 0: both voices sound at the same pitch and merge, and only the wandering pattern is heard.

How it works

Two identical chains of sequencer, oscillator (triangle), envelope and VCA. Both sequencers play the same pattern of five notes in eight steps: C, E, G, A, E. One runs at 120 BPM, a pass takes 1 s; the other at 126 BPM, 0.95 s. Every second it gains 0.4 steps: one sixteenth every 2.5 s. After 20 s it is a whole pass ahead, and both line up again. Transpose 7 raises the second voice by a fifth so that the two can be told apart. The mixer combines them, A on the left, B on the right (pan L 60 and R 60): with headphones the pattern wanders between your ears.

Polyrhythm 3 against 4

Open in the generator Modules: Oscillator, Noise, Filter, Amplifier (VCA), Clock, Envelope (ADSR), Sample & Hold

What it shows

Three against four: the tom hits three times while the block hits four times, both evenly spaced. Only the clock controls them, no sequencer. Every two seconds both meet on the same beat, and the hi-hat ticks the sixteenths in between.

Things to try

Set ÷A on the clock to ÷6: the block hits only twice, and three against four becomes three against two.
Set ÷A to ÷4: block and tom move in step, and the polyrhythm is gone.
Set swing on the clock to 66: the hi-hat swings and the block stumbles, because every second one of its hits falls on a delayed sixteenth. The tom on the quarters stays straight.
Set the range on Sample & Hold to 0: the hi-hat sounds the same on every hit.

How it works

The clock counts sixteenths, six per second at 90 BPM. ÷B (÷4) sends every fourth one to envelope “Tom”, ÷A (÷3) every third one to envelope “Block”. After 12 sixteenths, the least common multiple of 3 and 4, both are back at the start together. Unlike in “Phasing”, nothing drifts; the pattern repeats exactly. CLOCK sends a pulse on every sixteenth to envelope “Hi-Hat” and to Sample & Hold, which rolls a new cutoff for the high-pass each time. The tom is built like the bass drum in “Four on the Floor”: on each hit the envelope raises the pitch by an octave and briefly opens the VCA. The block uses the same noise as the hi-hat, but through a band-pass: it lets only a narrow band around the cutoff through, and with the short hit it knocks like wood.

Polyrhythm 5 against 4

Open in the generator Modules: Oscillator, Noise, Filter, Amplifier (VCA), Step sequencer, Clock, Envelope (ADSR)

What it shows

Five against four: the tom hits five times while the melody plays four notes. The tom is on the quarter notes, the melody runs across them. Every three seconds a figure of the melody starts on a tom hit, and the hi-hat ticks the sixteenths.

Things to try

Set ÷A on the clock to ÷4: melody and tom move in step.
Set ÷A to ÷3: four notes against three hits, as in “Polyrhythm 3 against 4”.
Set ÷A to ÷12: each note lasts three quarter notes, a three over the four-beat bar. The melody now takes six bars.
Set VCA “Hi-Hat” to 0: without the grid the melody seems to float freely above the tom.

How it works

The clock counts sixteenths, almost seven per second at 100 BPM. ÷B (÷4) sends every fourth one to envelope “Tom”, ÷A (÷5) every fifth one to SYNC of the sequencer, which then advances one step. Its eight steps are two figures of four notes, first A minor going down, then C major going down. Each figure lasts 20 sixteenths, as long as five tom hits. 20 is the least common multiple of 4 and 5, so every figure starts together with the tom. The tom is built as in “Polyrhythm 3 against 4”: on each hit the envelope raises the pitch and briefly opens the VCA. CLOCK sends a pulse on every sixteenth to envelope “Hi-Hat”, noise through a high-pass.

Pumping pad

Open in the generator Modules: Oscillator, Filter, Amplifier (VCA), Step sequencer, Clock, Envelope (ADSR), Mod mixer

What it shows

A pad that pumps in time with the bass drum: on every hit it ducks away and swells back up before the next one. In club music a compressor controlled by the bass drum does this (sidechain), here an inverted envelope. “Breathing filter” shows the same trick, there in time with the melody.

Things to try

On the mod mixer, set amount A from −100 to 0: the pumping stops, the pad stands still and covers the bass drum.
Set the decay of envelope “Pump” to 0.15: the pad only ducks briefly and springs back.
Set ÷B on the clock to ÷8: bass drum and pumping only come on every half note, and the groove gets heavy.

How it works

The clock runs at 124 BPM; the rhythm needs no sequencer. ÷B (÷4) sends a pulse on every quarter note to two envelopes: “Kick” shapes the bass drum as in “Four on the Floor”, “Pump” rises to 1 in 10 ms and falls back within 0.35 s. The mod mixer inverts it (amount A −100 %) and lifts it (offset 100 %): VCA “Pad” receives 1 − envelope, so the pad is open until the bass drum hits. ÷A (÷16) advances the sequencer once per bar: two bars of A minor, then F, C and G. The two sawtooth waves are a fifth apart and slightly detuned against each other, which makes the pad wide.

Tension (homage)

Open in the generator Modules: Oscillator, Noise, Filter, Mixer, Amplifier (VCA), Step sequencer, Envelope (ADSR)

What it shows

Tension from two notes: a low swing a semitone apart, with quiet noise underneath like distant surf.

Things to try

Set the FM depth to 0: a pure sine. On small speakers the low note can hardly be heard any more.
Set level B on the mixer to 50: the noise comes to the front.
Set BPM to 160: the swing gets faster, and the tension rises.

How it works

The delay keeps writing the sound into a memory and reads it back out after the set time. The value from Sample & Hold at the MOD input shifts this time by up to half. It jumps instead of gliding, and the read position jumps with it: when the time gets longer, the delay reads a piece that was already heard once more; when it gets shorter, it skips one. The pitch of the echoes stays the same. It only changes while the time glides. The scope shows the jumps as a staircase.

The distortion after the delay rounds the sum of tone and echoes to fixed heights. At feedback 50 every echo is half as loud as the one before and spans only half as many heights: 8, 4, 2, 1. Whatever lies below half a step drops out: there is no fifth echo. It also holds every value for a moment, at drive 50 a good 5000 times per second, and thereby adds side tones next to the harmonics.

Long arc

Open in the generator Modules: Oscillator, Filter, Mixer, Amplifier (VCA), LFO, Step sequencer, Envelope (ADSR), Sample & Hold

What it shows

The sequencer with 256 steps, its greatest length: a figure travels over the degrees C, A♭, F and G and only then starts again. Three sources move the filter at the same time.

Things to try

Set BPM to 120: the arc then lasts 32 instead of 19 seconds.
Click the three cables at the filter’s MOD input one after another: each takes away one movement. Ctrl+Z brings them back.
Set level B of the mixer to 0: the quiet sine tone underneath drops out.

How it works

Each block of 64 steps sits on its own degree (0, −4, −7, −5 semitones). At the filter, envelope (attack), LFO (slow drift) and Sample & Hold (a random value per note) add up.

Warbling tape

Open in the generator Modules: Oscillator, Amplifier (VCA), Delay (echo), LFO, Step sequencer, Envelope (ADSR)

What it shows

A worn tape echo: a slow LFO moves the delay time a little. Only the echoes waver in pitch, the attack stays clean.

Things to try

Set the LFO depth to 10: the tape wobbles clearly.
Set the LFO frequency to 5 Hz: the echoes flutter.
Set feedback to 80: every round wobbles differently, the echoes blur.

How it works

The LFO at the delay’s MOD input pulls the time of 0.35 s back and forth by ±3.5 ms, so at 0.5 Hz the echoes waver by about ±19 cents. The direct signal bypasses the delay path.

Harmonics and noise colors

Open in the generator Modules: Oscillator, Noise, Mixer, Distortion, Oscilloscope

What it shows

Two views of the same sound: the wave shows how the signal moves within 30 milliseconds, the spectrum which frequencies it is made of. The oscillator at the top, the same tone after the distortion in the middle (see the note “Distortion”), the noise below, each with one scope per view.

Things to try

Set the oscillator waveform to sine: a single peak remains in the “Osc” spectrum, the fundamental, and the wave turns round. A sine has no overtones.
Set the waveform to square: every second peak is missing, only the odd multiples remain (3, 5, 7 times). With triangle: the same ones, but much quieter, and the sound turns soft.
Set the oscillator frequency to 110: the pattern of peaks moves one octave to the left as a whole.
Set A on the mixer to 0 and B to 100, then the noise color to pink and to brown: the spectrum tilts down to the right, and the noise gets quieter and duller. In the wave, the scribble turns into a line that slowly wanders up and down.
Click the display in Main Out until it says “Spectrum”: it shows what arrives after the mixer, the peaks of the tone on top of the noise. The mixer changes what you hear and this display; the scopes sit before it.

How it works

A tone with a fixed pitch is made of sine tones: the fundamental (220 Hz here) and overtones at 2, 3, 4 times its frequency (440, 660, 880 Hz …). The waveform sets how loud each overtone is. A sawtooth has all of them, getting evenly quieter towards the top. In the spectrum, frequency runs to the right, the vertical lines sit at 100, 1000 and 10,000 Hz, and every octave is equally wide. Noise never repeats, so it shows no peaks but an area. White has the same energy at every frequency, pink the same in every octave, brown falls off even more steeply and rumbles like surf.

Distortion

The distortion sits between oscillator and mixer; the “Dist” scopes show the tone after it. At drive 0 the sound passes almost unchanged.

Things to try

Set the oscillator waveform to sine, then drive to 50 and to 100: in the wave the crests flatten, in the spectrum peaks grow at 3, 5 and 7 times the fundamental. Step by step the sine turns into a square.
Set type to fold, drive 100: the crests fold over several times instead of flattening: within every half-wave the wave swings up and down several times. The peaks at 7 to 13 times stand as high as the fundamental. Turn drive back slowly: the peaks rise and fall in turn.
Set type to steps, drive 70: the wave turns into a staircase. Far to the right of the fundamental, peaks appear in pairs that sit on no multiple: tones that do not belong to the overtone series.

How it works

The distortion bends the wave, and every bend brings overtones. Saturation and fold bend top and bottom alike, so only odd multiples appear, as with the square. Steps holds every value for a moment; its peaks depend on the rate of that holding, not on the pitch. Even at drive 0 the curve is not perfectly straight: from a sine a small peak at 3 times remains.

Phaser from notch filters

Open in the generator Modules: Oscillator, Filter, LFO, Oscilloscope

What it shows

Three notch filters in a row each cut a notch into the sawtooth. The LFO moves all three up and down together; the sound sweeps and swooshes like a phaser.

Things to try

Set the LFO depth to 0: the notches stand still, leaving a calm sawtooth with a slightly different color. Only the movement makes them clearly audible.
Click the cables from the LFO to “2” and “3” to remove them: only one notch moves, the effect gets weaker.
Set the LFO frequency to 1 Hz: the sweep turns into a bubbling.

How it works

A notch filter removes the frequencies around its cutoff and leaves the rest almost unchanged. Q sets the width of the notch; the bandwidth is roughly cutoff divided by Q. The three sit at 300, 600 and 1200 Hz, an octave apart. The LFO is plugged into all three MOD inputs and moves the notches once in just under 7 s between a quarter and 1.75 times their cutoff and back; they stay an octave apart. In the spectrum three valleys wander through the overtones. A real phaser forms its notches differently, from allpass filters and the dry signal, but sounds similar.

Robot voice

Open in the generator Modules: Oscillator, Filter, Ring modulator, Amplifier (VCA), Distortion, Step sequencer, Envelope (ADSR), Sample & Hold

What it shows

The ring modulator multiplies the melody with a low square wave, which turns it into a buzzing, metallic tone. A resonant filter shapes it into sounds like syllables, Sample & Hold picks a new one for each note. The distortion (type steps) at the end turns the wave into a staircase and thereby adds highs that the filter no longer removes.

Things to try

Set the ring modulator’s amount to 0: only the sawtooth remains and the melody becomes clear.
Change the frequency of oscillator “Mod” (square) from 30 to 150 Hz: the voice turns more metallic.
Set the range of Sample & Hold to 0: all syllables sound the same.
Set drive on the distortion to 0: the highs drop out, the voice sounds duller.
Set drive on the distortion to 100: it now holds only 600 values per second. The buzz turns coarser, the tones break off abruptly.

How it works

The square wave contains only odd harmonics (30, 90, 150 Hz …); each one puts sidebands around the melody, and the pitch blurs. The filter acts like a mouth, Sample & Hold opens it to a different width on every note.

The distortion after the VCA rounds the finished voice to fixed heights and holds every value for a moment, at drive 50 a good 5000 times per second. The edges of this staircase are tones far above the filter’s cutoff. Because the distortion sits after the filter, they stay; before the filter hardly any of them would be heard.

Signals made visible

Open in the generator Modules: Oscillator, Filter, Amplifier (VCA), LFO, Step sequencer, Envelope (ADSR), Oscilloscope

What it shows

Control signals are normally invisible; you only hear what they do. Three oscilloscopes show the slow LFO, the envelope of every note and the spectrum of the finished sound.

Things to try

Change the LFO frequency: the wave in the roll view gets tighter or wider, the filter moves faster.
Change the envelope’s decay or sustain: the spikes in oscilloscope “ADSR” change shape.
Turn the cutoff: high overtones vanish from or appear in the spectrum.
Click a display: wave → roll → spectrum.

How it works

The sequencer plays the oscillator (sawtooth), the filter shapes the tone, the VCA the volume. The envelope opens the VCA on every gate, the LFO moves the filter frequency. An output may have several cables: LFO and envelope also go into an oscilloscope, which changes nothing about the sound.

Clock with swing

Open in the generator Modules: Oscillator, Noise, Filter, Amplifier (VCA), Step sequencer, Clock, Envelope (ADSR)

What it shows

One clock module drives kick, bass, hi-hat and melody. Swing delays every second sixteenth, the kick on the quarter notes stays straight.

Things to try

Swing: 50 % straight, 66 % like triplets, 75 % dotted.
Change the BPM on the clock: all voices follow.
Set ÷A to ÷4: the melody walks in step with the kick.
Set ÷B to ÷16: the kick only hits on the downbeat.

How it works

CLOCK sends a pulse every sixteenth to sequencer “Bass” and envelope “Hi-Hat”, ÷A every third one to sequencer “Lead”, ÷B every fourth one to envelope “Kick”. Swing only moves every second sixteenth, and the quarter notes never fall on one. The melody’s 8 steps take 24 sixteenths, the bass needs 16. Only after three bars do both meet again on the downbeat.

Vowel filter

Open in the generator Modules: Oscillator, Filter, Amplifier (VCA), Step sequencer, Envelope (ADSR), Sample & Hold, Oscilloscope

What it shows

A highpass and a lowpass in a row let only a narrow band through, similar to a vowel. Sample & Hold moves the lowpass on every note, so each one sounds like a different vowel.

Things to try

Set the highpass cutoff to 20 Hz: the sound gets fuller and the vowel character fades. In the spectrum, low harmonics join on the left.
Set the resonance of both filters to 12: the vowels get clearer and start to whistle.
Set smooth on Sample & Hold to 0.3: the vowel moves on to the next one during the note instead of jumping.
Set the range of Sample & Hold to 0: always the same vowel.

How it works

The highpass removes what lies below 320 Hz, the lowpass what lies above 1100 Hz. With resonance each edge gets a peak, similar to the formants of the voice. Depending on where the lowpass sits, a different harmonic stands out. The scope after the lowpass shows the spectrum: the harmonics form a hill that changes shape with every vowel.

From buzz to clang

Open in the generator Modules: Oscillator, Ring modulator, Distortion, LFO, Oscilloscope

What it shows

The ring modulator multiplies the tone of oscillator “A” by oscillator “B”. The LFO pulls “B” from 40 to 160 Hz in ten seconds and then jumps back. At the bottom it buzzes, at the top it clangs like metal, and in between one sound tips over into the other. At the very bottom the same sound runs through a distortion (see the note “Distortion”).

Things to try

Set transpose on “B” to −24: the sweep now runs from 10 to 40 Hz. At the bottom the buzz turns into a flutter, and the bulges in the “Ring” wave grow wide.
Set the waveform on “A” to sine: the “Ring” spectrum keeps two peaks that move apart, at 220 Hz minus and plus the frequency of “B”. Without overtones it hardly clangs.
Set the amount on the ring modulator to 50: the tone of “A” stays audible, and its peak stays in the “Ring” spectrum between the pairs.

How it works

Multiplying means: “B” turns the volume of “A” up and down, through zero, twice per cycle. The “Ring” wave shows the tone of “A” in bulges. Up to about 15 bulges per second the ear hears them one by one; above that they blur into a rough buzz. In the spectrum every partial of “A” becomes a pair, the partial minus and plus the frequency of “B”. When the pairs lie close together, they rub; when they move apart, the ear hears separate tones. They no longer belong to the overtone series of 220 Hz, which is why it sounds metallic. The LFO's sawtooth at the IN of “B” raises it evenly by two octaves; this input cannot do more than one octave up and one down.

Distortion

The distortion sits between the ring modulator and Main Out; the “Dist” scopes show the sound after it. At drive 0 the sound passes almost unchanged.

Things to try

Set the waveform on “A” to sine, then drive to 50: the “Ring” spectrum shows two peaks; in the “Dist” spectrum new ones grow to their left and right.
Set drive to 100: in the “Dist” wave the bulges turn into a square wave, all blocks equally high, only of different widths. The spectrum fills up. It gets louder as well; level makes up for that.
Set type to fold, drive 100, and transpose on “B” to −24: where the bulge in the “Ring” wave is high, the “Dist” wave swings tightly packed, at its edges loosely.

How it works

From a single tone the distortion makes overtones. After the ring modulator, however, several tones are present at once, and then combination tones appear as well: sums and differences of the tones and their multiples. Two peaks quickly turn into dozens. Saturation also lifts quiet passages until they stand as high as the loud ones: that is why the bulges disappear, and why it gets louder. Fold turns the wave over the more often, the higher it swings: the overtones swell and fade with the bulge.

Wandering melody

Open in the generator Modules: Oscillator, Filter, Mixer, Amplifier (VCA), Delay (echo), Step sequencer, Envelope (ADSR)

What it shows

One sequencer clocks the other: the GATE of sequencer “Bass” is plugged into the SYNC of sequencer “Lead”. The melody only advances on bass notes and therefore shifts against the bar.

Things to try

Switch a step in sequencer “Bass” on or off: the melody wanders in a different pattern.
Change the BPM on sequencer “Bass”: both follow.

How it works

The bass plays 3-3-2 twice, six notes per bar. The melody has eight notes, so it starts two notes later every bar and is back at the beginning only after four bars.

Two stages

Open in the generator Modules: Oscillator, Amplifier (VCA), Delay (echo), LFO, Step sequencer, Envelope (ADSR), Sample & Hold

What it shows

Two VCAs in a row: the first shapes each note with the envelope, the second chops it with LFO and chance. The same envelope also controls Main Out and so cuts off the echoes between the notes as well.

Things to try

Click the cable from the envelope to Main Out: the echoes ring into the gaps.
Set the LFO frequency to 2 Hz: slow pulsing instead of flutter.
Set the range of Sample & Hold to 0: all notes pulse the same.

How it works

At the MOD input of VCA “2”, LFO and Sample & Hold add up, giving a different pattern on every note. Main Out comes after the delay, so the envelope there also hits the echoes.

ModuloOne is a modular synthesizer that runs in your browser: connect modules with cables and hear what comes out. Every example is just a starting point: on the canvas you can repatch everything, save it as your own patch and share it as a link. To the generator

Sound examples for the modular synthesizer

Basic course

Lesson 1: A tone

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If it stays silent

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Lesson 2: Filter

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If it stays silent

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Lesson 3: Envelope and VCA

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How it works

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Lesson 4: Sequencer

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If it stays silent

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Lesson 5: LFO

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Lesson 6: Stereo echo

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Lesson 7: Space and chance

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Part 2, lesson 1: Distortion

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Part 2, lesson 2: Ring modulator

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If it stays silent

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Part 2, lesson 3: Mod mixer

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Part 2, lesson 4: Clock

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If it stays silent

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Part 2, lesson 5: Randomness

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Where to go from here

Interactive

Harpsichord

What it shows

Things to try

How it works

Two registers

Electric piano with tremolo

What it shows

Things to try

How it works

Touch and tremolo

Grand piano

What it shows

Things to try

How it works

Why the note grows darker

Für Elise, tap along

What it shows

Things to try