P33

Objectives

By the end of this chapter you will be able to:

  • Explain in one sentence what a sampler does.
  • Identify the PO-33’s three BPM presets by name and number.
  • Name three reasons why 40 seconds of sampling memory is enough.
  • Make a single sound and play it back.

Musical concept: what is a sampler?

A sampler is a musical instrument that records a sound and then lets you play the recording back on command. A microphone hears the sound. A computer stores the recording. A speaker plays the recording back, or samples it. The word sample in modern music means both a recorded sound (“I sampled a cat meowing”) and the act of recording it (“I sampled my guitar”).

The PO-33 is a pocket sampler. It fits in your hand. It runs on two AAA batteries. It can record up to 40 seconds of audio total, across all 16 slots. You record a sound, you store it in a slot, and then you play it back from the slot. The PO-33’s distinctive feature — the thing that makes it different from earlier pocket samplers — is the 16-step sequencer: 16 numbered buttons that you can use to play back your samples in a pattern, one step at a time, in a loop.

This book assumes you have either a real PO-33 or a Ravine: Phoenix firmware running on an ESP32-S3 board. The buttons, the sequencer, and the audio quality are similar; the differences are flagged in sidebars.

The three BPM presets

The PO-33 has three preset tempos: Hip Hop (80 BPM), Disco (120 BPM), and Techno (140 BPM). BPM stands for beats per minute. 80 BPM means 80 beats fit into 60 seconds — each beat lasts 0.75 seconds. 120 BPM means each beat lasts 0.5 seconds. 140 BPM means each beat lasts about 0.43 seconds.

The presets are not arbitrary. 80 BPM is the bottom of the comfortable walking tempo — slow enough to sway to, fast enough to feel motion. 120 BPM is exactly two beats per second — easy to count, the tempo of disco and most house. 140 BPM is fast — the tempo of techno, drum’n’bass (mostly), and “Tencho” (PO-33 slang for techno slowed down enough that you can play it on the grid — actually the PO-33 just calls it “Techno”).

Sidebar — PO-33 manual vs. Ravine: Phoenix firmware. The real PO-33 calls them “HIP HOP”, “DISCO”, and “TENCHO” (with the typo, which is intentional, a Teenage Engineering joke). The Ravine: Phoenix firmware displays them the same way.

You can also fine-tune the tempo anywhere from 60 to 240 BPM by holding the BPM button and turning Knob B. You will use this feature in Part IV when we explore genres outside the three presets.

Why 40 seconds is enough

The PO-33 gives you 40 seconds of total recording time, divided among 16 slots. Most slots will hold a few seconds of audio — a drum hit (less than half a second), a vocal phrase (a few seconds), a synth chord (one or two seconds). The longest single sample you can record is about 10 seconds if you use only one slot.

Why is this enough? Because the PO-33 is a sequencer, not a recorder. A sequencer plays a short sound many times. A 0.25-second kick drum sample, played sixteen times in a loop at 120 BPM, fills 8 seconds of music. The PO-33 is designed to make music out of short sounds repeated often, not out of long sounds played once.

This is the most important idea in the book. The PO-33 is a loop machine. Its limitations are loops. When you finish this book, you will be making beats by recording 16 short sounds, looping them, and layering the loops.

The three limits and why they help you

The PO-33 has three hard limits:

  1. 40 seconds of sample memory total.
  2. 16 sample slots total.
  3. 16 steps per pattern.

These limits are not arbitrary. They were chosen by Teenage Engineering to force you into creative decisions. A 64-step DAW encourages you to fill every step. A 16-step sequencer forces you to leave most steps empty — and the empty steps are where the groove lives. A 40-second memory budget forces you to commit to short sounds — and short sounds loop better than long ones. A 16-slot limit forces you to pick your 16 favourite sounds — and that picking is where your musical taste develops.

This is the second-most important idea in the book. Limits are creative tools. When you feel stuck, ask yourself “what is the smallest change I could make?” — that is almost always the right question on a PO-33.

PO-33 translation: recording your first sound

The PO-33 has 16 numbered pads. Each pad is both a sound selector and a step button. The same physical pad means different things depending on which modifier you hold.

To record a sound into slot 1:

  1. Hold the REC button (a star symbol on the real PO-33).
  2. Press pad 1. The screen now shows a recording timer.
  3. Make the sound you want to record — talk, clap, snap, sing, hit a desk, whatever.
  4. Release REC.
  5. The sound is now stored in slot 1.

To play back the sound:

  1. Hold SOUND and press pad 1. This selects slot 1 as the active sound — the PO-33’s two-step “select sound” flow.
  2. Release SOUND, then press pad 1 (or any pad). The selected sound plays. Pressing different pads plays the same sound at different pitches/slices — the pads are a keyboard for the selected sound, not a “pad N = slot N” map.
  3. To make it repeat, write it into the sequencer. We’ll do that in Chapter 2.

Sidebar — Ravine: Phoenix firmware. The Ravine: Phoenix firmware’s button layout is identical to the real PO-33. REC is the star button on GPIO 41. Pad 1 is the top-left of the 4×4 grid. There is no functional difference for the operator.

Guided exercise: record and play back your first sound

You will need: a PO-33, a quiet room, and one object that makes a sound.

Success criteria: you have a recording in slot 1, and — after selecting it with SOUND + 1 — it plays back when you press a pad.

  1. Find a quiet room. The PO-33’s built-in microphone will pick up everything, including your breathing. Hold the device about 15 cm from your mouth.
  2. Hold REC.
  3. Press pad 1.
  4. Say your name out loud. Keep it under 2 seconds.
  5. Release REC.
  6. Select the sound (hold SOUND + press pad 1), release SOUND, then press pad 1. Your name should play back.
  7. If it doesn’t, check the trim — you may have recorded only silence. The PO-33 displays the recording’s waveform; if it is flat, you didn’t record anything.

If your recording has silence at the start (because you pressed REC and then took a moment to start talking), trim it. The PO-33’s trim lives in Tweak Trim mode: tap the FX button until the mode reads TRIM (each tap cycles Tone → Filter → Trim → Tone). Then turn Knob A to move the start point and Knob B to move the end point. We will return to trim in detail in Chapter 5.

Creative challenge: record three contrasting sounds

Record three more sounds, each into its own slot:

  • A percussive sound (clap, snap, hit) into slot 1.
  • A tonal sound (sing a vowel, hum a note) into slot 2.
  • A long sound (whistle, sigh, slide) into slot 3.

Play each one back. Notice how the percussive sound has a clear attack and decay. The tonal sound has a clear pitch. The long sound has neither. These three sound types are the three building blocks of every piece of music you will ever make on the PO-33.

Listening assignment

Listen to J Dilla, “Workinonit” from Donuts (2006). The entire beat is built from short drum samples looped into a 16-step pattern. Notice how many of the steps are empty. Notice how the beat breathes.

Listen to Daft Punk, “Da Funk” (1995). The bassline is a 1-second sample of an analogue synth, looped 16 times per bar. The drum loop is 4 short samples, layered.

Listen to Madlib, “Accordion” from Madvillainy (2004). The entire beat is one sample (a looped accordion figure) plus a kick and a snare. Two drum sounds plus one loop, four total samples. This is the PO-33’s native format.

Summary and checkpoint

Key takeaways:

  • A sampler records sound and plays it back.
  • The PO-33 has 40 seconds of memory, 16 slots, and 16 steps. These limits are creative tools.
  • The three BPM presets are 80 (Hip Hop), 120 (Disco), and 140 (Tencho). Fine-tune with Knob B.
  • Record by holding REC + a pad. To play: select the sound (hold SOUND + a pad), then press a pad.

Self-check:

  • [ ] Can you explain in one sentence what a sampler does?
  • [ ] Can you name the three BPM presets and their tempos?
  • [ ] Can you record a sound into slot 1 and play it back?
  • [ ] Do you understand why “fewer samples, used cleverly” is the PO-33 ethos?

If you answered “yes” to all four, move on to Chapter 2.