Meet the PO-33 — a pocket sampler

This is a side session — the first step beyond the core five, and a complete change of pace. The PO-33 K.O! is an entire sampler, sequencer and effects box that fits in one hand. Nothing else is needed: it has its own microphone, its own little speaker, and runs on two AAA batteries. In this session we record our own sounds, turn them into a beat, and jam — all on this one tiny device.

It works as a standalone — the core sessions aren’t required. But it’s a lovely break from the bigger setup, and the instincts carry straight across.

Part A — Power on and make a sound (about 10 min)

1. Put in the batteries

   Insert two AAA batteries, minding the + and − ends. The PO-33 powers on by itself — there’s no on/off switch. The screen shows a little clock.

2. Set the volume

   Hold bpm and tap a numbered key from 1 to 16 — that key number sets the output volume. Start gentle at key 4, then raise it to taste.

3. Hear what's in the slots

   Hold sound and tap key 1 to land on the first sound, then tap keys 1–16 to play it. Now hold sound and tap key 9 and play keys 9–16. Some slots may already hold sounds; empty ones are silent — those are the ones we’ll record into next.

   📖PO-33 K.O! manual — Selecting and playing sounds

4. Press play — and meet the demo beat

   Press play. On a brand-new PO-33 a beat starts — one we didn’t make. The device ships with a handful of factory sounds and demo patterns, and play simply starts whichever pattern is loaded. Press play again to stop it.

   Notice it keeps looping on its own — tapping keys or selecting sounds doesn’t start or stop it. That little loop is the sequencer at work. The next section explains exactly what’s happening, and later we’ll clear this demo and build our own.

How the PO-33 thinks (about 10 min)

Before building a beat, it’s worth picturing what’s going on inside — because the PO-33 is really two machines sharing one set of keys, and mixing them up is the single biggest source of “wait, why is it doing that?”

Two machines: the instruments and the sequencer

1. The instruments — 16 sounds. Each numbered key holds a sound. Tapping a key plays that sound right now, by hand, like hitting a drum. Nothing is recorded — it’s just a noise on demand.
2. The sequencer — the pattern. A saved loop that taps those sounds for us, automatically, over and over.

Pressing play starts the sequencer; pressing it again stops it. The pattern runs entirely on its own. Choosing a sound (sound + a key), or choosing none at all, only changes which instrument our own taps will play — it never starts, stops, or changes the running loop.

The words: sequencer, step, loop, pattern

These four terms describe one simple machine. In plain language:

• Step — the PO-33 chops one bar of music into 16 equal slots called steps, laid out across the 16 numbered keys. Picture 16 little boxes in a row; each box is one moment in time. A box either holds a hit (a sound fires there) or sits empty (silence).
• Loop — it plays those 16 steps left to right, then jumps back to step 1 and goes again, forever, until stopped. That endless once-through is the loop. One trip through all 16 steps is one bar.
• Playhead — while it loops, an unseen cursor sweeps across the 16 steps in time with the beat. Whenever it lands on a step that holds a hit, that sound fires.
• Sequencer — the machine that does all of the above for us. Instead of tapping a sound by hand over and over, the sequencer remembers where the hits go and plays them on repeat.
• Pattern — one filled-in 16-step grid: which sounds fire on which steps. The PO-33 holds many patterns; we build them one at a time and can chain them into a song later.

Each sound has its own lane

Here’s the part that answers “how do I get a specific sound onto a specific step”: every sound has its own on/off across the 16 steps — its own lane. All the lanes share the same 16 keys, but only one shows at a time. While building a pattern, the lit keys show the steps of whichever sound is currently selected; select a different sound and the lights switch to show that sound’s steps. So a beat is built one sound at a time — select the kick and mark where it hits, select the snare and mark where it hits, and so on. There’s only one pattern grid here; the PO-33 has no separate side-by-side tracks like a bigger groovebox.

The whole picture, nested

Zoom out and it’s boxes inside boxes — far fewer than the Digitakt. From the outside in:

• Memory — one shared pool of 40 seconds of recording time, kept inside the device. No card, no computer.
• Sound slots — 16 of them, split in two:
  • Melodic (keys 1–8) — the recorded sample is spread across the keys as a scale, so each key plays the whole sound at a different pitch.
  • Drum (keys 9–16) — the sample is sliced, so each key fires a different piece of it — one hit per key.
• Pattern — the 16-step loop from above. It points at the sound slots; it doesn’t store the audio itself.
• Pattern chain — patterns played back-to-back as a song, up to 128 in a row.

Where these live — and the one big gotcha

Part B — Record our own sounds (about 20 min)

1. Sample from the built-in microphone

   Hold record and hold a destination key: pick a key 1–8 for a melodic sound or 9–16 for a drum sound. The mic records for as long as the keys are held — release to stop. The screen counts down the seconds left in the 40-second pool, so keep takes short.

   A good first pass: hum or sing a steady note into a melodic slot (1–8), and tap a tabletop or clap into a couple of drum slots (9–16).

   📖PO-33 K.O! manual — Sampling with the microphone

2. Or sample from line-in

   Plug a 3.5 mm cable from a sound source — a phone, or the Kawai’s output — into the PO-33’s line-in jack. With a cable inserted, it records from line-in instead of the mic. Then sample exactly as before: record + a destination key while the sound plays.

3. Trim the sample — on the FX parameter pages

   A fresh sample usually has a little silence at the front or a long tail. We tidy that on the sound’s parameter pages. First select the sound to edit: sound + its key.

   Now the part that isn’t obvious. With a sound selected and the pattern not playing, fx doesn’t add effects — it steps through that sound’s parameter pages. Tap fx to cycle tone → filter → trim (the screen names the page it lands on). Stop on trim, then turn A to set where the sound starts and B to set its length. The sample re-triggers as the knobs move, so the edit can be heard while it’s made.

   Reference clip not recorded yet — capture this and save it under public/audio/, then add src="/audio/…".

   ⚠️ If the sound starts late or has a long silent tail, nudge knob A (start) and knob B (length) until it triggers tight.

   📖PO-33 K.O! manual — Trim, tone & filter — the FX parameter pages

Part C — Build a pattern (about 22 min)

Now we put the sequencer to work. The idea from the last section in one line: in write mode the numbered keys stop being instruments and become the 16 steps of the pattern — we draw the beat instead of playing it — and each sound has its own lane, so we build it one sound at a time.

1. Start from a clean slate

   If a demo beat is still looping, stop it with play, then empty the pattern: hold record + pattern to clear the active pattern. Now the 16 steps are blank and waiting for our own sounds.

2. Pick the sound to place

   Hold sound and tap the key of the sound to sequence first — a kick-like drum slot (keys 9–16) is a good start. This chooses whose lane we’re about to draw: everything we mark next lands on this sound’s 16 steps, until we pick another sound.

3. Turn on write mode and place steps

   Press write to enter write mode. The 16 numbered keys now stand for the 16 steps of the bar, not for playing the sound. Tap a key to switch that step on for the selected sound — it lights up, meaning “fire this sound here.” Tap a lit step again to switch it off.

   For a steady four-to-the-floor kick, light up steps 1, 5, 9 and 13. Press play to hear the loop while editing — the pattern cycles and each lit step fires as the playhead passes it.

   📖PO-33 K.O! manual — Write mode — drawing a pattern

4. Or tap it in live

   Prefer to play by feel? Start the loop with play, then hold write and tap the sound’s key in time with the beat. Each tap is recorded onto the nearest step (snapped to the grid, following the swing setting), so it stays in time even when our timing is loose. Both ways write to the same lane — whichever feels natural.

5. Read the lights, fix mistakes

   In write mode the lit keys always show the selected sound’s lane — the steps where it fires. Tapped a step by accident? Tap the lit step again to clear it (the same on/off toggle as the Digitakt grid). Switch the view to a different sound’s lane any time with sound + its key.

6. Set the tempo

   Press bpm to step through the tempo presets. For an exact tempo, hold bpm and turn B (60–240 BPM); hold bpm and turn A to add swing.

   📖PO-33 K.O! manual — BPM and swing

7. Layer a second and third sound

   Select another sound (sound + its key). Its lane appears on the keys — empty at first — and we draw or tap in its steps the same way over the same loop. Build it like a drum loop: something steady on the beat, something on the offbeats, one bit of character. Each sound keeps its own lane; together they make the pattern.

   Reference clip not recorded yet — capture this and save it under public/audio/, then add src="/audio/…".

   ⚠️ No single sound should dominate. Re-trim or re-pitch a slot if a part is poking out.

Part D — Perform, then let it save (about 15 min)

1. Punch in effects

   While the pattern plays, hold fx and tap a key 1–15 — the effect lasts only while held, like a punch-in. To bake an effect into the pattern, turn write on first, then apply it; to clear saved effects, hold fx + key 16 with write on.

   📖PO-33 K.O! manual — Punch-in effects (FX)

2. Chain patterns into a song

   Make a second pattern: hold pattern + an empty key, then write a new loop into it. To play patterns in order, hold pattern and tap the pattern keys one after another — up to 128 in a chain, repeats allowed.

   📖PO-33 K.O! manual — Selecting and chaining patterns

3. Let it save

   There’s no save button. The PO-33 writes everything to memory when it auto-powers-off after a few idle minutes. Before swapping batteries or packing it away, let it settle so the latest sounds and patterns are safely stored.

That’s a whole track — sampled, sequenced and performed — on one box that fits in a pocket. The instincts behind it (a sample, a step, a pattern that points at sounds) are exactly the ones from the Digitakt sessions, just shrunk down. The other gear waiting in the wings — the Bestie mixer, the Chase Bliss pedals, the PO-32 — slots in from here the same way: one device, one job, at a time.