Roland SMP to WAV converter

Over the last couple of years I owned 2 Roland SP404 MK2. Bought the first one, hated it, sold it. Found new interest, bought another one, sold it again. I, of course, saved all my projects ‘for later’ but did not export the samples and got stuck with a huge pile of Roland’s proprietary SMP-files – a format the device uses that is distinct from the .WAV files it exports. Since their was no tool for conversion available I decided to try this on my own. Comparing SMP files with their exported WAV-counterpart showed an identical file-size between the 2 formats. By using little more than 1 sloppy AI prompt I was then able to decode the SPM container and create a python-script that you can use yourself.

The SMP format uses a RIFF-like 32-byte header, but with big-endian fields (unlike WAV’s little-endian ones): a “RFWV” magic number, followed by the total file size, sample rate, channel count, and bit depth. Immediately after the header sits a fixed block of roughly 480 extra bytes that don’t correspond to the actual sample. This appears to be leftover data from the sampler’s internal recording buffer — a byproduct of flash memory not being wiped between takes, so a trace of a previous recording lingers there. Past that block, the real audio begins: standard interleaved 16-bit little-endian PCM, sample-for-sample identical to the exported WAV (aside from occasional single-bit rounding noise, inaudible in practice).

With the format mapped, converting .SMP files to standard .WAV is straightforward — just parse the header, skip the buffer remnant, and wrap the PCM data in a proper WAV container. You can use the converter provided on this website or take a look at the corrsponding github repository if you want to get a deeper inside into the code: https://github.com/andymann/roland-smp-to-wav-converter

Since everything is happening in your browser locally you can also point to complete folders and have them converted recursively. Tests on my side all went cool – it just works.