The SP-404MK2's patterns cannot be opened directly on a computer for playback. To play back a pattern on your computer, first resample the pattern to convert it to a sample, then export it as a WAV file.
- Resample the pattern.
See "Sampling a pattern (RESAMPLE)" in the SP-404MK2 Reference Manual. - Export the sample.
See "Exporting samples (EXPORT SAMPLE)" in the SP-404MK2 Reference Manual, or "Exporting Samples" in the SP-404MK2 App User's Guide.