PO33 WEB manual

Everything the drum machine does, key by key. It has 16 synthesized sounds, a 16-step sequencer, 16 chainable patterns and 16 effects to play live.

Getting started

1. Press Play or the space bar. Demo pattern 1 starts. Browsers only allow audio after you touch something, so your first press also switches the sound on.
2. Look at the display: the top left says STEPS, and below it is the sound you are editing, KICK 1. The first time, the machine starts with the Tonic kit; after that it opens with the last kit you picked with the KIT button.
3. Tap keys 1–16. Each one is a step in the bar. Tapping a lit step turns it off; tapping an empty one turns it on.
4. Press Sound, tap another number (for example 2, Snare 1) and press Sound again. Now the steps you tap belong to the snare.
5. Turn knob A to change the sound's pitch and knob B to change its character (morph).
6. Hold FX and press a number to throw in an effect while it plays.
7. Want other sounds? Press KIT at the bottom of the board to switch between five kits, or press the button next to it (it shows the slot number) to put any of the 80 sounds in the selected slot, or record your own with the mic. See Sound kits and Recording with the mic.
8. Want a melody on top? Press SYNTH at the top of the board: it is a second machine, a synthesizer in the style of the OP-1, that plays in time with the drums. For bass lines, press BASS: a third machine in the style of the TB-303. See Three machines in sync.
9. Press App at the top of the board to install the machine on your phone or computer and play offline. See Install.

The panel

The layout copies the PO-32: three function keys across the top next to the two knobs, and a column of functions to the right of the 16 numbers.

Each number has two printed labels: above it, the sound it triggers (the selected sound is highlighted), and below it, its number and the effect it applies in FX mode. Along the top and bottom edges of the board there are a few extra controls:

How modes work

The machine is always in one of five modes, and the mode decides what the 16 numbers do. The mode name shows at the top left of the display.

Sound, Pattern, BPM and FX work two ways:

• Short press: the mode stays on. Press Sound and let go: you stay in SOUND. Press it again to go back to STEPS.
• Hold: the mode lasts while you hold. Hold Sound, tap a number (or turn a knob) and let go: you return to the mode you were in. This is the quick way, just like on the Pocket Operators.

Switching modes cancels any step lock, stops building the pattern chain and turns off any effects.

The display

The display has five areas, top to bottom:

1. Status line. The mode on the left, followed by a blinking REC when recording is on. On the right, the current pattern and tempo, for example P01 118.
2. Large text. The main thing for the mode: the sound name, the pattern chain, the tempo or the active effect. When you move something, it briefly shows the value you are changing (for example PITCH +3).
3. Small text. The detail. In STEPS and SOUND: sound number, pitch in semitones and morph from 0 to 100 (01 PITCH +0 MOR 20). In BPM: swing and volume. In PATTERN: what the next tap will do.
4. Strip of 16 cells. In STEPS, SOUND, BPM and FX these are the 16 steps of the selected sound: a block is a hit, a block with a hole in the middle is a locked hit, and a low line is an empty step. The small dash moving above them is the playhead; if it blinks over a step, that step is locked and being edited. In PATTERN these are the 16 patterns: block = pattern with content, line = empty pattern, mark above = in the chain (the one playing blinks).
5. Oscilloscope. The waveform of whatever is playing. At rest it is a dotted line.

The lights

Every key has a light at its top left. What it means depends on the mode:

Programming steps

A pattern has 16 steps: four beats of four sixteenth notes. Steps 1, 5, 9 and 13 fall on the beats.

1. Choose the sound: Sound + number.
2. In STEPS mode, tap the steps where you want that sound. Tap again to remove it.
3. While the machine is stopped, adding a step plays the sound, so you hear what you are programming.
4. Switch sounds and repeat. Each sound has its own row of 16 steps in the pattern, and they all play together.

Sounds

All 16 sounds are synthesized on the fly, with no recorded samples. This table is the Pocket kit; the other kits are in Sound kits. Knob A moves the pitch up to 12 semitones (one octave) either way. Knob B (morph) changes each sound's character in its own way:

The closed and open hats choke each other, like on a real kit: a closed hat cuts off an open hat that is still ringing.

Sound kits

The real PO-32 can load new sounds from a computer. Here, the KIT button at the bottom left of the board opens a menu that swaps all 16 sounds at once. Each kit shows its color and style. There are five kits:

All kits are synthesized live, like the rest of the machine. Tonic and Rhythm use a re-creation of the Microtonic engine (see below); the others are approximations inspired by those devices.

• Patterns don't change. They store steps by key number, so the same pattern plays different sounds in each kit, like loading a new sound pack on the PO-32. Switching kits is a quick way to hear a beat in a new way.
• Each kit remembers its own settings. Pitch and morph for each sound are saved per kit, so going back to a kit brings back your tweaks.
• When you switch, the display shows KIT and the kit name, and you hear the selected sound.
• Each kit has its own sound character. A mix color runs over the whole drum machine: Pocket is fat and punchy, Rhythm warm and dark, Tonic clean and punchy like the PO-32, Arcade crunchy 8-bit and Analog warm with big lows. The same beat sounds clearly different on each kit.
• Each kit has its own accent color. The board stays black, but its details (pads, holes, trace dots, the playhead glow and the Manual and kit buttons) change color: gold for Pocket, green for Rhythm, blue for Tonic, purple for Arcade and orange for Analog.

Tonic and Rhythm: the Microtonic engine

The real PO-32 Tonic doesn't play recordings: its sounds are synthesized by Sonic Charge's Microtonic. Tonic and Rhythm run on a re-creation of that engine, built from the formulas Sonic Charge publishes: an oscillator with a pitch sweep, filtered noise with its own envelope, Microtonic's distortion curve, an EQ and a level in dB.

• Tonic uses real Microtonic factory sounds, placed in the PO-32's slot order. The PO-32's own factory kit isn't published, so these are the closest factory sounds, not exact copies.
• Knob B morphs between two sounds, like on the PO-32: the name says which ones. Shaker/Zap is a shaker on the left and a zap on the right, Hi-hat goes from closed to open, Clave/Cow from claves to cowbell, Tom/Kick 3 from tom to kick, Tamb/Crash from tambourine to crash. Every slot starts fully on the left.
• One voice per column on Tonic, as on the hardware: keys 1, 5, 9 and 13 share a voice, and so do 2/6/10/14, 3/7/11/15 and 4/8/12/16. A new hit in a column cuts the one that is ringing, and if two keys of the same column play on the same step, only the lower-numbered one sounds. Keep the kick and the bass on different steps.
• Rhythm is built on the same engine with the PO-12's character: a low-passed kick with a little drive, a trashy snare and a darker, warmer mix. The PO-12 mixes recordings and synthesis and its sounds aren't published, so this kit is an approximation.

Mixing your own kit

Any of the 16 slots can hold any of the 80 sounds, so you can replace sounds in a kit or build a mix from several kits.

1. Select the slot you want to change: Sound + number. The button at the bottom right of the board shows the slot number (for example 06) and the sound in it.
2. Press that button. A menu opens with one tab per kit and its 16 sounds in a 4×4 grid, laid out like the keys. Tap any sound: it goes into that slot only and you hear it. The menu stays open so you can try others; close it with ×, Esc or by tapping outside.
3. Repeat for other slots. The display confirms each change with SLOT 06 and the sound's name.

• An edited kit shows a star, for example Tonic *. Each kit keeps its own mix, and the other kits stay as they were.
• To go back to a kit's original 16 sounds, open KIT and tap ↺ Reset at the bottom of the list twice (the first tap asks you to confirm). It only appears when the kit has changes.
• A new sound in a slot starts with its default pitch and morph.

Editing a drum sound

Every drum sound can be reshaped with four knobs, in the style of the OP-1.

1. Select the sound (Sound + key), press the slot button at the bottom right of the board and choose ✎ Edit this sound at the top of the menu.
2. An editor opens over the top of the board. The keys below stay playable, and tapping another key switches the editor to that sound.
3. Turn the four knobs. You hear the change right away and the display shows the value.

• An edited sound shows a star next to its name in the editor.
• ↺ Reset puts that sound back the way it came with the kit.
• Edits are saved per kit and per key. Knob B (morph) still works on top of them. Swapping the sound in a key from the slot menu clears its edits.
• Close the editor with × or Esc.

Recording with the mic

Like the PO-33 K.O!, you can sample any sound with your phone's or computer's microphone and play it from any key.

1. Select the key you want to record onto: Sound + number.
2. Press the slot button at the bottom right of the board and open the Mic tab.
3. Tap the red button to turn the mic on. The first time, the browser asks for permission.
4. Hold the red button and make your sound: a voice, a clap, a pot lid. The bar shows the level and the display shows REC MIC 01 with the time. Let go to stop (it stops by itself after 4 seconds).
5. The recording goes onto that key and plays back. Record again to replace it.

• Cleanup is automatic. Silence at the start and end is cut and the volume is matched to the other sounds. If it was too quiet, the display says TOO QUIET.
• 16 mic slots. The Mic tab shows them in a 4×4 grid with their length. Tap a recording to put it on the selected key (any kit, any key), or tap an empty slot to record there next. The dashed slot is where the next recording goes.
• Knobs: A changes the pitch (it plays the recording faster or slower) and B shortens its tail.
• Saved on your device. Recordings stay in this browser or app and work offline. They are never uploaded.
• The mic turns off as soon as you close the menu or leave the Mic tab.

Tip: use headphones or stop the beat while you record, so the drums don't end up in the recording.

Three machines in sync

PO33 WEB is really three machines wired together: DRUMS, a pocket drum machine, SYNTH, a synthesizer in the style of the OP-1, and BASS, a bass line machine in the style of the TB-303. They run on one clock, like devices synced with a cable, so they always stay in time. The steps below use SYNTH; BASS works the same way.

1. Build a beat on DRUMS and press Play.
2. Press SYNTH at the top left of the board (or the M key). The board turns into the synth and the drums keep playing.
3. Press Play. The display says NEXT BAR and the Play light blinks amber: the synth waits and joins exactly at the start of the next bar. Press Play again before then to cancel.
4. Program or play your melody while the beat runs. Switch back and forth as much as you like.

• Each machine has its own Play. Stopping one doesn't stop the other. The clock stops when both are stopped.
• The lights on the DRUMS · SYNTH · BASS switch show what is running: red pulses on the beat while a machine plays, amber blinking while it waits for the next bar.
• Each machine has its own 16 patterns, chain, sounds and FX. Effects you hold only affect the machine you are on.
• Shared by both: tempo, swing and Write.
• Each machine has its own volume, so you can balance the synth against the drums. Set it in BPM mode with the numbers 1–16, or with the white Volume knob on SYNTH. The display says DRUMS VOL or SYNTH VOL.

The synth

SYNTH follows the design of the OP-1: an aluminium body, a black screen with coloured bars, four coloured knobs (blue, green, white, orange) that are always on the board, and grey square keys. The function keys sit in one row, and the 16 note keys in two rows of eight below them.

Playing and writing notes

The 16 keys are notes. They climb a scale from low to high, so everything you play is in tune; the label above each key shows its note (for example C3, E4).

• Live: in SOUND mode the keys work like a keyboard. A note sounds for as long as you hold the key, and fades out with the release when you let go. With Write on and the synth playing, what you play is recorded onto the nearest steps.
• Step by step: choose a note (Sound + key) and tap the steps where it plays in STEPS mode, exactly like drums. Several notes on the same step make a chord.

Engines

The ♪ button at the bottom left picks the engine. Each engine has its own four controls on the Engine page:

The four knobs

The knobs always control the page selected above them. The screen shows their values as four coloured bars.

• Drag a knob up or down, use the mouse wheel over it, or focus it and use the arrow keys.
• Env amount opens the filter with the same envelope as the volume. LFO wobbles the filter once per beat.
• In BPM mode the knobs become Tempo, Swing and the synth's Volume.
• With a step lock (hold a step in STEPS mode) the knobs become Pitch and Tone for that single note, so you can bend it even outside the scale.
• ↺ Reset puts the current engine back the way it came. Each engine remembers its own settings.

Key, scale and octave

The button at the bottom right shows the key and scale (for example C · Major). Open it to choose the octave (−2 to +2), the key (C to B) and the scale: Major, Minor, Pentatonic, Minor penta, Dorian, Blues or Chromatic. Each scale shows its notes. Changing them re-tunes the 16 keys, and patterns you already wrote follow along.

Pattern 1 on SYNTH comes with a short demo in C major that fits the drum demo.

The bass

BASS is a bass line machine that behaves like the Roland TB-303, the acid classic, in a body that follows the Teenage Engineering EP-133 K.O. II: warm light-grey plastic, chunky keys, dark function keys and an orange Play.

• One note at a time. Like a real bass, it plays a single note. If a step has several notes, the highest one plays. Live keys are monophonic too: a new key cuts the one before.
• Low register. The 16 keys climb the scale from C2. Key, scale and octave are in the button at the bottom right, separate from SYNTH (it starts in C minor).
• Accent and slide per step. Hold a step in STEPS mode: the knobs become Pitch, Accent and Slide for that note. Accent makes the note louder and its filter snap harder. Slide makes the note glide into the next one without restarting it — the classic acid move. Steps with accent or slide show an amber light.

Presets and knobs

The ♪ button at the bottom left picks a preset: Acid, Square, Rubber, Deep or Screamer. Each one remembers its own knobs, and ↺ Reset puts it back.

Turn the cutoff low and the resonance and env mod high for the squelchy acid sound. Pattern 1 on BASS comes with a demo acid line in C minor that fits the drum demo.

Phone and Bluetooth speakers can't play very low notes. If the bass sounds thin or distorted, pick a speaker mode with the EQ button (see Sound output), use headphones or raise the octave in the key and scale menu.

Knobs A and B

• Drag the knob up to raise it and down to lower it. Sideways movement counts too, at half strength.
• Mouse wheel or trackpad over the knob: step-by-step adjustment.
• Keyboard: ↑ ↓ move A and ← → move B. Hold Shift for fine adjustment.

What they control depends on the moment:

• Normally: pitch and morph of the selected sound, across the whole pattern.
• With a locked step: only that hit (see step lock).
• In BPM mode: tempo and swing. The labels under the knobs change to show it.

While the machine is stopped, turning a knob plays the sound so you can tune it.

Step lock

Gives a single hit its own pitch or morph, for example a bassline with different notes or a kick with one longer hit.

1. In STEPS mode, hold a step for half a second. If it was empty, a hit is created.
2. The display shows LOCK and the step's light blinks. Let go of the key.
3. Turn A or B: only that hit changes. The display shows STEP 05 and LOCK P +3 M -- (P is pitch, M is morph; dashes mean that parameter follows the sound's overall value).
4. To exit, tap the same step again. Tapping another step also exits (and toggles that other step).

A locked hit shows an amber light and a hole in its cell on the display. To remove a hit's lock, enter it (hold it) and press Clear once.

Patterns and chains

There are 16 patterns. The first three come with demos: a groove (1), a variation with toms and cowbell (2), and a sparser one with zaps and the LFO effect (3). They are made for the Tonic kit.

Switching patterns

Hold Pattern and tap a number. If the machine is playing, the change happens at the end of the bar (the display says QUEUED: NEXT BAR), so the beat never breaks.

Chaining

Hold Pattern and tap several numbers in a row: 1 1 2 3 plays pattern 1 twice, then 2, then 3, and loops. A chain can hold up to 64 patterns and shows on the display as 01>01>02>03.

The chain keeps growing while you stay in PATTERN mode. Once you leave the mode and come back, the next tap starts a new chain.

Live recording

To play the sounds like pads and have them recorded:

1. Press Play.
2. Press Write. Its light blinks and the display shows REC.
3. Switch to SOUND mode (short press on Sound).
4. Tap the numbers in time. Each hit lands on the nearest step and stays in the pattern.
5. Press Write again to stop recording.

Recording knob movement: with recording on and the machine playing, turn A or B. The value is written into the selected sound's hits as they pass, like an automatic lock. Use it for a pitch sweep on the bass or to slowly open up the cymbal.

Copying patterns

1. Turn on Write.
2. Enter PATTERN mode. The display says TAP COPY TARGET.
3. Tap the number of the target pattern. The current pattern is copied there in full (locks included) and the display confirms COPIED with PATTERN 01 > 05.

Tempo, swing and volume

Hold BPM (or leave it on) and:

• Knob A: tempo from 60 to 200 BPM. Starts at 118.
• Knob B: swing from 0 to 100%. Delays the even steps (2, 4, 6…) so the beat feels less rigid.
• Numbers 1–16: volume of the machine you are on (DRUMS and SYNTH each have their own). Starts at 12. The lights show a level bar.

Effects

Effects are played live and are not saved in the pattern: they last while you hold the number. Hold FX (or Shift) and press one or more numbers at once. Let go and everything goes back to normal.

Combining effects

• Sound effects stack (for example Bitcrush + Echo + Octave −).
• Only one filter works at a time. If you hold several, the lowest number wins (Lowpass, then Highpass, Bandpass and Sweep).
• Only one timing effect works at a time. Priority order: Retrig, Loop 1, Loop 2, Loop 4, Half, Reverse, Random.
• Octave + and Octave − together cancel out.

The loop, retrig and half effects anchor to the step that was playing when you pressed. If the machine is stopped, they anchor to step 1.

Clearing

• Clear a sound from the pattern: press Clear twice in a row (within a second and a half). The selected sound's row is emptied. The first press turns the light amber and the display asks CLEAR?.
• Clear the whole pattern: the same, but in PATTERN mode.
• Remove a lock: with a locked step being edited, a single press removes its own pitch and morph (UNLOCKED).

There is no undo.

Keyboard

On DRUMS, the 16 numbers sit in a 4×4 block on the keyboard, in the same shape as the panel:

The function keys behave like the panel keys: a short press leaves the mode on, or hold J and tap W to pick sound 6 and drop back to the steps when you let go.

On SYNTH and BASS

On the note machines the keyboard is laid out to play: the two rows of notes sit on two rows of the keyboard, upper notes on the upper row and lower notes on the row below. The function keys move to the number row.

To play notes like a keyboard, switch to SOUND mode first (1); in STEPS mode the same keys turn steps on and off. Other letters do nothing on these machines.

Saving

Everything saves automatically in this browser: patterns, locks, each sound's pitch and morph, tempo, swing and volume. If you open the machine in another browser or on another device, it starts from the demo patterns.

To go back to factory state, clear the site's data in your browser settings.

Sound output (speakers)

Bluetooth and phone speakers can't play deep bass. When they get a lot of it, their amplifier clips and everything sounds distorted. The EQ button at the top right of the board picks the output mode:

• All modes keep a limiter on the output, so the signal never reaches the speaker above its maximum, even with all three machines at full volume.
• The EQ button fills in while a speaker mode is on. Your choice is saved on this device.
• Still distorting? Lower the volume of the loudest machine in BPM mode (usually DRUMS or BASS), or lower the speaker's own volume a bit.

Install and use offline

You can install the machine as an app. It opens full screen, has its own icon and works offline: after the first visit, everything is stored on the device.

The easy way: press ↓ App at the top right of the board. In Chrome, Edge and on Android it opens the install dialog straight away. On iPhone, iPad and Safari on Mac, browsers don't allow a button to install, so it shows the steps for your device instead. The button disappears once the machine is installed.

You can also do it from the browser:

Your patterns are saved in the browser or app where you use it. On iPhone, the installed app keeps its own patterns separate from Safari, so what you make in one doesn't show up in the other.

When a new version is out, it downloads in the background and shows up the next time you open the machine.

Coming from the PO-32

The keys sit in the same places as on the PO-32, so its tutorials help you find your way. Here is what maps across and what is different: