RE2-YM2203 - Project RE:birth 2nd Sound Card

What is it?

Project RE-birth 2nd is the spiritual continuation of Project RE-birth — a legendary open hardware project dedicated to bringing classic FM sound chips back to life.

In 2021, for unknown reasons, the Japanese closed the ym2203.com website, deleted all public schematics, and stopped the distribution of all peripheral hardware. Even with money in hand, it became impossible to purchase any SPFM motherboard or rebirth module. This was deeply frustrating for enthusiasts worldwide.

In the absence of original hardware, I forked almost all RE-birth music modules to truly revive this project. My mission: make FM music chips available to people all over the world — no internal meetings, no mystery stores, no hunger marketing, just long-term stock and fair play for everyone.

The RE2-YM2203 is a YM2203 (OPN) sound card designed for the SPFM series. The circuit is fully redesigned by myself and is compatible with the RE:birth bus. It can be used with SPFM Light, SPFM Lite, RESPFM, IAP-RESPFM and other compatible motherboards.

About the YM2203 Chip

The YM2203, also known as OPN (FM Operator Type-N), is a classic Yamaha FM synthesis chip combining 3 channels of 4-operator FM synthesis with a built-in 3-channel SSG (PSG) section — giving you both FM and square-wave sound from a single chip. It was famously used in NEC PC-88 and PC-98 computers, defining the sound of Japanese PC gaming throughout the 1980s.

With the RE2-YM2203, you can experience that iconic dual-voice character — warm FM tones layered with crisp PSG chiptune — driven by the authentic hardware chip, not emulation.

Key Features

• Authentic YM2203 (OPN) — 3-channel FM + 3-channel SSG on one chip
• Stereo PSG support with freely adjustable stereo configuration via 3-position switch (original design)
• Compatible with RE:birth bus standard
• Works with SPFM Light, SPFM Lite, RESPFM, IAP-RESPFM and more
• Classic NE5532 dual op-amp for excellent audio output quality
• Adjustable volume control on-board
• Excellent digital-to-analog isolation for clean, noise-free sound
• Standardized RE:birth module form factor
• Long-term stock — always available, no artificial scarcity

Supported Chips

• OPN: YM2203
• PSG/SSG (built-in): AY8910-compatible

Compatible Mainboards

• SPFM Light
• SPFM Lite (2 slots)
• RESPFM
• IAP-RESPFM (4 slots)
• STM32-RESPFM (4 slots)

Why Did I Make It?

I referred to the ps98-YM2203 schematic and pictures of the original rebirth module, as well as the SPFM Tower schematic, to faithfully recreate this module. My dream is simple: to make SPFM and RE:birth modules available to everyone in the world — no gatekeeping, no mystery shops, fair play to all.

Thanks to the extensive experience accumulated in designing MegaMod and other RE:birth modules, this module was designed and validated within a week.

What Makes It Special?

The RE2-YM2203 features a clean, minimal appearance with the YM2203 chip logo and key parameters printed on the board. It uses the classic NE5532 universal dual operational amplifier, delivering adjustable volume, excellent sound quality, and solid digital-analog isolation — fully in the spirit of Project RE:birth.

In particular, RE2-YM2203 supports stereo PSG, and the stereo configuration can be freely adjusted through the three-position switch. This is an original design not found on other modules — giving you creative control over the spatial character of your PSG sound.

The RE:birth module design philosophy pursues the ultimate in sound quality, standardized appearance, and thoughtful bus layout with proper ground plane isolation. This module honors that philosophy completely, making it both a functional audio tool and a piece of hardware worth studying — just like a textbook.