little-scale — How to: Prepare Samples and Create LSDJ Kits (2008)

The canonical kit-making tutorial, and the one the forum threads keep pointing back to. Its subject is the half the wiki did not have: what to do to a sample before lsdpatch ever sees it.

Key claims#

• The budget is time, not count. "You only have just over two seconds worth of audio per kit, so whatever you put in has to count!" In the patcher, a kit is 3FA0 bytes; the figure turns red when the samples overflow it.
• Crop hard, and crop in three places: the silence before the attack, the tail once the sound has said what it says, and any dead space inside. His worked example — a Sega Mega Drive rhythm-guitar sample — goes "from being more than 500 milliseconds in length to a mere 75 milliseconds, and it still has the important essence of what it was".
• Roll off the highs at the Nyquist limit: "with a sampling rate of 11.468 KHz we have an upper limit determined by a nyquist frequency of 5.734 KHz". Rolling off the lows and removing DC offset as well "will make normalisation more effective".
• Fade to kill clicks: cropping leaves clicking or popping at the edges — "even a fade of a few milliseconds" fixes it.
• Normalise, then add gain on purpose. "Because sample playback tends to be quiet in comparison to the other LSDJ channels, it is also recommended that gain is added after the normalisation process. Although this will clip your sample" — 3 to 6 dB. "Yes, it looks terrible but it doesn't sound too bad."
• Export format: PCM, mono, 11.468 kHz, 8-bit. Name each sample with three characters, because that name is what appears in LSDj.
• In the patcher: pick a kit slot, create the kit, add samples until 3FA0 is nearly full, drop any you do not want, compile, rename, compile again; export a .kit to share or a whole modified ROM.
• A commenter adds the advice the forum threads later repeat: filter brutally, "remove all unnecessary frequencies with a hard low-pass and high-pass filter … you may even cut into the fundamental", because it plays back better on the hardware.

Practical takeaways#

• Three numbers carry the whole workflow: 3FA0 bytes per kit, 11.468 kHz, 5.734 kHz Nyquist.
• Every millisecond you crop is another sample you can fit — crop before you filter.
• Deliberate clipping is correct here: the kit channel is quiet against the others, so normalise and then push 3–6 dB more.

Notable quotes#

"You only have just over two seconds worth of audio per kit, so whatever you put in has to count!"

"Yes, it looks terrible but it doesn't sound too bad."

Relevance to the wiki#

lsdpatch documents the patching end; this documents the preparation, with the byte budget and the sample rate that explain why kits sound the way they do.

To verify#

• Written in 2008 against LSDJ Patcher v5 and Peak/QuickTime; the current lsdpatch resamples and dithers on import, so some steps (8-bit export in particular) may now be done for you (unverified).

Pages touched#

chip-samples · recording-samples · lsdpatch · lsdj · little-scale · game-boy-apu · multisampling · sample-looping · levels-and-headroom