Multisample instruments

A multisample instrument holds several recordings of one sound, one per note (a Juno pad sampled every few semitones, say). Each key plays the nearest recording, repitched by the distance, so the sound stays natural across the keyboard instead of stretching one sample over five octaves.

The Tracker loads them from SFZ files, a plain-text format most sample packs and samplers use.

Get an SFZ

Many packs ship one: copy the pack folder (WAVs and .sfz together) to the card.

For a folder of note samples without an SFZ, tools/make_sfz.py writes one on the computer, from the file names:

tools/make_sfz.py ~/Samples/MyPack

It looks into every subfolder, reads the note from a leading MIDI number (054 Dusty Pluck Junos F#2.wav) or a note name (Pad C3.wav), and skips folders with fewer than 8 notes (kits, chords). --name-octave 3 is for packs that call middle C "C3"; --dry-run shows what it would write. Then copy the folders to the card.

Load it

1. In the Sample Loader, pick an empty instrument on the right.
2. Select the .sfz file and press Add. A panel opens instead of loading at once:

Key	Sets
F1 Low / F2 High	the note range to load
F3 Every	the spacing: every note, 2nd, 3rd, 4th, 6th or 12th
F4 Max length	cuts each note to 8 s ... 0.5 s with a short fade (Full keeps them whole)
Size	what it takes in sample memory (shown only)
F6 Cancel / F8 Load

Turn the encoder to change the selected value. The panel says how many notes the SFZ has, which ones it will load and how much memory is left. It opens with values that fit in about half the free memory, so another instrument still fits; Load is greyed while the choice doesn't fit or no note is in the range.

At most 48 notes go into one instrument: space them out or narrow the range for a bigger pack. A spacing of a 3rd or 4th note usually sounds as good as every note.

Play it

The instrument plays like any other: pads, the pattern, MIDI in. Its Sample Playback page shows the ninth play mode, Multi:

• Zone (F1) steps through the loaded notes and Root shows each one's note; F5 zooms. The zone edges stay where the loader put them.
• Switching to another play mode keeps the notes: switch back to Multi any time.

Good to know

• Multisamples load mono, as one-shots: SFZ loops, velocity layers and round robins aren't used yet. Each note plays to its end (or its Max length).
• The notes are saved in the project like any sample. Stock firmware and the Tracker Mini open the project too and play the instrument as a Slice instrument, one slice per note.
• Long samples take a lot of memory: a 10 s mono note is about 0.9 MB. Max length is the quickest way to fit a pack.