there is no formal academic "paper" on the Edirol SD-90 soundfont
Because the hardware is discontinued, digital soundfonts (.sf2) have been created by the community through extensive sampling of the original unit.
Introduction
The EDIROL SD-90, released in 2001, was a flagship soundfont module from Edirol, a renowned Japanese electronics company. At the time, soundfonts were a popular way to create custom sounds for music production and live performances. The SD-90 was designed to provide professional-grade sound quality, flexibility, and ease of use. Even though it's no longer in production, the SD-90 remains a sought-after module among musicians, producers, and sound designers.
Many “papers” in synth forums are actually detailed DIY investigations.
Check midi.org technical archives or VOGONS (old sound hardware forum). edirol sd-90 soundfont
⭐ Pro Tip: If you use the soundfont version, you may need to manually balance the levels. Fan-compiled "Touhou Soundfonts" are often noted by users on Reddit as being unbalanced, requiring extra mastering to sound like the original games.
For the purist: hunt a used Edirol SD-90 (or the cheaper SD-20). Connect via old 5-pin MIDI and record the analog outs. Nothing sounds exactly like the real blue box. there is no formal academic "paper" on the
The "SoundFont" version of the SD-90 is a collection of those internal samples ripped, converted, and formatted for use in software samplers like FL Studio’s Fruity Soundfont Player, SFZ players, or even the SoundBlaster cards of old. It democratized the hardware, allowing producers who couldn’t afford the rack unit to access its pristine pianos and lush pads.