Sampler

The Sampler is ARC-24's fourth performance surface: a fixed 4×4 grid (sixteen pads) of your own audio per song. Import files or record from the mic, play one-shots or Keys mode, and overdub onto any armed track (T1–T8).

Everything you do with samples — assigning, editing, Pads/Keys, Set Source, Set Root, Chop, and Clear — happens right on the Sampler performance screen. There's nothing to set up in Sound Design.

Tracks become sample tracks automatically

You don't pick "Synth" or "Sample" anywhere. A track simply follows what you do:

• An empty track becomes a Sample track the moment you enter Sampler mode and record (or perform) pad hits on it.
• Once a track has a recorded synth or drum part, it stays that type — and the Sampler screen shows a banner instead of the pads, with shortcuts to Use T[N] (jump to the next empty track — or an existing sample track when none are free) or Clear Track [N] (delete the loop, after a confirmation, so this track can be reused). The reverse is also true (a recorded sample track stays a sample track until you clear it).
• Tapping a track that already holds recorded sample hits automatically switches the performance surface to the Sampler, so the pads always match the selected track.

Sample audio files are song-wide (shared by all loops). Each loop remembers which tracks hold sample parts, the Pads vs Keys layout, the Keys mapping, and the Keys source pad.

Perform vs Edit

A toggle at the top-right of the grid sets what tapping a pad does:

When you first enter Sampler mode with no pads loaded, the toggle is hidden and you're placed in Edit mode so you can assign sounds right away — the header shows a "Tap a pad to add a sample" hint instead. The toggle appears once at least one pad has a sample (and starts on Perform); clearing the last pad hides it again and returns you to Edit mode.

Pads | Keys and the Perform/Edit toggle share the header row. Pads/Keys only appear in Perform mode.

Assigning & editing pads (Edit mode)

Switch the toggle to Edit, then tap a pad. This opens the pad settings sheet — the first of two screens you use to work with samples.

• iPhone: sheet over the performance screen
• iPad: centered modal window

Tap Done when you're finished on this screen. Changes to the shape knobs apply immediately; import, record, and edit work is saved from the second screen (below).

Pad settings (screen 1)

Tap the mini pad preview (when a sample is loaded) to audition the pad with your current shape settings.

Import, record, or edit (screen 2)

Tapping Import, Record, or Edit on the pad settings sheet opens a second screen for working with the audio file itself:

Import opens the system file picker first; once you choose a file, the trim/tempo screen appears. Record and Edit go straight to that screen.

This screen does not include volume, pan, pitch, attack, or release — set those on the pad settings sheet.

First assign on an unsaved session: ARC-24 creates a song automatically so files can be stored with the project. On an already-saved song, samples are added to that project.

Changing the song tempo later

Sync to song tempo stretches the sample once, at the song tempo in effect when you save. If you change the song BPM afterwards, synced pads keep playing at the old stretch — they don't re-time automatically.

To re-time a synced pad after a tempo change:

1. Switch to Edit and tap the pad to open its settings
2. Tap Edit to open the trim / tempo screen
3. Tap Save — the stretch is recalculated against the current song tempo

Repeat for each synced pad. Pads without Sync to song tempo are unaffected by BPM changes.

Channel effects: EQ and all FX (tone reverb, Atmosphere, Character, delay, inserts) for a sample track are in Mixer → FX, exactly like a synth track — there's no separate sampler mixer strip. Use the normal T1–T8 strip, or tap FX in the extras row on the performance screen (same sheet as Mixer → FX).

Pads layout (Perform)

Each pad triggers its assigned sample as a one-shot — it plays from the Start trim point to the End trim point, then stops. Empty pads show Empty.

Keys layout (Perform)

Keys plays one source sample across all sixteen pads, pitched relative to a root pad. Keys is Perform-mode only, and its controls sit on the header row (in place of the Perform/Edit toggle):

Until you set a root, the source pad acts as the root (unison). Tapping the root pad always plays — it doesn't clear the root. The effective root pad shows a dashed orange ring.

Pad labels show interval + sample name (e.g. +M3 / -P5 in Scale mapping, or +3 st in Chromatic).

Keys mapping (Scale vs Chromatic)

Mapping follows your loop's key/scale from Setup. Changing key or scale updates Scale-mode pitch live.

Recording sampler loops

1. Enter Sampler mode and select a track tab (T1–T8)
2. Arm the track (same as Notes — the empty track auto-types to a sample track)
3. Press Play
4. Tap pads — hits record onto that track's loop

Use per-track quantize and humanize in Sound Design → Track → Recording (same controls as synth tracks).

Loop events store the pad index and Keys root pad (so playback pitch matches what you played in Keys mode).

Chop

Sample chopping splits one loaded pad into several smaller pads, each playing a slice of the same audio. Use it to pull individual hits out of a loop, break, or long recording — without leaving the performance screen or re-importing files.

Turn Chop on from the extras row — the scissors icon (Pads layout only; at least one pad must already have a sample). Tap a source pad to loop its sample while you work, then tap empty pads on the beat to mark where each slice starts and ends. Each slice becomes a one-shot on the pad you armed. The original source pad is never changed; chopped pads share the same file with different trim regions. Chop is session-only — it isn't saved with your song.

The chop screen stays minimal: just the waveform and your pads. While Chop is on, a How To button appears at the right of the header row (where Perform / Edit normally sits) with a step-by-step refresher; a short message appears below the waveform only if something goes wrong (for example, tapping a pad that already has a sample) and fades on its own.

Rules:

• Two taps per slice — the first tap only arms the pad; audio is assigned on the next tap
• Sequential pads work — tap P6 to arm, tap P7 to finish P6 and arm P7, and so on
• Loop wrap auto-save — if the preview cycles before you tap an end mark, the armed slice is saved from its start mark through the source trim end
• Catching the top of the loop is forgiving — taps are compensated for audio output latency, and an arm tap landing just before or just after the loop wraps snaps to the very beginning of the region (so you can grab the downbeat without splitting hairs on timing)
• Empty destination pads only — loaded pads are ignored (a brief message below the waveform explains if you tap one)
• Chopped pads share the source file with different trim regions (clearing a pad deletes the file only when no other pad still references it)
• Chop, Clear pad, and Erase are mutually exclusive
• Loop recording is blocked while Chop is on
• Not available in Keys layout — switch to Pads first

Clear pad (performance)

On the Sampler screen, the extras row shows a dashed-square icon between Chop and Erase.

• Empty pads are ignored
• Shared files are kept until no pad still references them
• Clear pad, Chop, and Erase can't be on at the same time
• Session-only toggle — not saved with your song

Use Clear pad to free a pad quickly during performance. Use Erase (hold while playing) to remove recorded loop hits, not the sample itself.

Erase

With Erase on and playback running, hold a sampler pad to remove matching hits on the armed sample track (same playhead-scrub model as Notes and Drums). Erase does not remove the sample — use Clear pad for that.

Tips

• Save As copies the sample folder to the new song; loop recordings are per-loop (duplicating a loop does not duplicate audio files).
• Tempo sync bakes a stretched file at save time; if you change the song BPM later, re-open each synced pad's Edit screen and hit Save to re-time it (see Changing the song tempo later).
• Detect estimates a sample's BPM from its rhythm — handy before turning on Sync to song tempo. If a sample has no clear pulse, set the BPM by hand or tap it in.
• Sync to song tempo needs a known original BPM — the toggle is disabled until a BPM is set (type, tap, or Detect).
• Use wired headphones or speakers when recording tight loops — Bluetooth adds latency.
• MIDI — with Enable MIDI Input on, consecutive notes from Setup → MIDI → Pad Base Note trigger the sixteen pads (Pads = sample hits; Keys = pitched source). See MIDI input.

Related

• Recording
• Erase mode
• MIDI input
• Mixer — channel EQ and FX for sample tracks
• Songs, loops & arrangement