GM programs 0-15
FM, algorithm 7, 4 operators
Envelope
Spectrum
- Attack
- 4.5 ms
- Decay
- 405.6 ms
- Release
- 126.1 ms
- Peak / RMS
- -19.1 / -35.7 dBFS
- Spectral centroid
- 279 Hz
- Noise vs. tone
- tonal
MACHINE
Mega Drive YM2612 + SN76489
Metallic, percussive FM tones layered with punchy square-wave chords - two very different chips sharing one mix.
ITS VOICES
How it makes sound.
The Sega Mega Drive carries two sound chips: the Yamaha YM2612 has six FM voices (one is often reassigned to play sampled drums instead), and the Texas Instruments SN76489 adds three square-wave tone channels and one noise channel - up to ten voices in total.
chipvoice spreads melody, chords and bass across the FM voices and the SN76489's tone channels, and plays drums from the reassigned FM voice and the noise channel.
HEAR EVERY PRESET
Its instruments.
Every preset a user can pick for this chip - played as one fixed probe, measured, never typed by hand.
Melody
GM programs 16-127
FM, algorithm 4, 4 operators
Envelope
Spectrum
- Attack
- 4.5 ms
- Decay
- 251.4 ms
- Release
- 115.6 ms
- Peak / RMS
- -16.5 / -32.1 dBFS
- Spectral centroid
- 289 Hz
- Noise vs. tone
- tonal
GM programs 32-37
FM, algorithm 4, 4 operators
Envelope
Spectrum
- Attack
- 6 ms
- Decay
- 431 ms
- Release
- 33.3 ms
- Peak / RMS
- -16.6 / -23.8 dBFS
- Spectral centroid
- 287 Hz
- Noise vs. tone
- tonal
GM programs 38-39
FM, algorithm 2, 4 operators
Envelope
Spectrum
- Attack
- 109.3 ms
- Decay
- 335.2 ms
- Release
- 33.3 ms
- Peak / RMS
- -20.7 / -28.3 dBFS
- Spectral centroid
- 676 Hz
- Noise vs. tone
- tonal
GM programs 40-87
FM, algorithm 4, 4 operators
Envelope
Spectrum
- Attack
- 4.5 ms
- Decay
- 252.9 ms
- Release
- 130.6 ms
- Peak / RMS
- -16.6 / -26.4 dBFS
- Spectral centroid
- 281 Hz
- Noise vs. tone
- tonal
GM programs 56-63
FM, algorithm 5, 4 operators
Envelope
Spectrum
- Attack
- 6 ms
- Decay
- 193.1 ms
- Release
- 141.1 ms
- Peak / RMS
- -18.2 / -32.0 dBFS
- Spectral centroid
- 793 Hz
- Noise vs. tone
- tonal
Chords
GM programs 0-15
FM, algorithm 7, 4 operators
Envelope
Spectrum
- Attack
- 4.5 ms
- Decay
- 405.6 ms
- Release
- 126.1 ms
- Peak / RMS
- -19.1 / -35.7 dBFS
- Spectral centroid
- 279 Hz
- Noise vs. tone
- tonal
GM programs 16-127
FM, algorithm 4, 4 operators
Envelope
Spectrum
- Attack
- 4.5 ms
- Decay
- 251.4 ms
- Release
- 115.6 ms
- Peak / RMS
- -16.5 / -32.1 dBFS
- Spectral centroid
- 289 Hz
- Noise vs. tone
- tonal
GM programs 32-37
FM, algorithm 4, 4 operators
Envelope
Spectrum
- Attack
- 6 ms
- Decay
- 431 ms
- Release
- 33.3 ms
- Peak / RMS
- -16.6 / -23.8 dBFS
- Spectral centroid
- 287 Hz
- Noise vs. tone
- tonal
GM programs 38-39
FM, algorithm 2, 4 operators
Envelope
Spectrum
- Attack
- 109.3 ms
- Decay
- 335.2 ms
- Release
- 33.3 ms
- Peak / RMS
- -20.7 / -28.3 dBFS
- Spectral centroid
- 676 Hz
- Noise vs. tone
- tonal
GM programs 40-87
FM, algorithm 4, 4 operators
Envelope
Spectrum
- Attack
- 4.5 ms
- Decay
- 252.9 ms
- Release
- 130.6 ms
- Peak / RMS
- -16.6 / -26.4 dBFS
- Spectral centroid
- 281 Hz
- Noise vs. tone
- tonal
GM programs 56-63
FM, algorithm 5, 4 operators
Envelope
Spectrum
- Attack
- 6 ms
- Decay
- 193.1 ms
- Release
- 141.1 ms
- Peak / RMS
- -18.2 / -32.0 dBFS
- Spectral centroid
- 793 Hz
- Noise vs. tone
- tonal
Bass
GM programs 0-127
FM, algorithm 4, 4 operators
Envelope
Spectrum
- Attack
- 7.5 ms
- Decay
- 431 ms
- Release
- 34.8 ms
- Peak / RMS
- -16.6 / -23.8 dBFS
- Spectral centroid
- 288 Hz
- Noise vs. tone
- tonal
GM programs 38-39
FM, algorithm 2, 4 operators
Envelope
Spectrum
- Attack
- 110.7 ms
- Decay
- 335.2 ms
- Release
- 34.8 ms
- Peak / RMS
- -21.0 / -28.3 dBFS
- Spectral centroid
- 684 Hz
- Noise vs. tone
- tonal
Drums
Kick
Tone
Envelope
Spectrum
- Attack
- 1.5 ms
- Decay
- 329.3 ms
- Release
- 0.4 ms
- Peak / RMS
- -32.7 / -55.8 dBFS
- Spectral centroid
- 1985 Hz
- Noise vs. tone
- mixed
Snare
Tone
Envelope
Spectrum
- Attack
- 1.5 ms
- Decay
- 345.7 ms
- Release
- 0.4 ms
- Peak / RMS
- -33.7 / -56.5 dBFS
- Spectral centroid
- 1600 Hz
- Noise vs. tone
- mixed
Hi-hat
Noise
Envelope
Spectrum
- Attack
- 1.5 ms
- Decay
- 287.3 ms
- Release
- 0.4 ms
- Peak / RMS
- -38.1 / -61.8 dBFS
- Spectral centroid
- 507 Hz
- Noise vs. tone
- tonal
Open hi-hat
Noise
Envelope
Spectrum
- Attack
- 1.5 ms
- Decay
- 374.1 ms
- Release
- 0.4 ms
- Peak / RMS
- -38.1 / -58.6 dBFS
- Spectral centroid
- 723 Hz
- Noise vs. tone
- mixed
HOW WE CHECK
Its evidence.
How closely this chip's emulation matches the real hardware, from the conformance harness that runs before each release.
Digital parity
Compared with Nuked-OPN2 1.0.12 (Nuke.YKT): 100.0 % identical (2,566,533,768 of 2,566,533,768 cycles), 0 of 10 logs with any divergence.
First divergence: none, every measured cycle is identical.
Compared with MAME sn76496 (Sega VDP PSG, 76c7d197): 90.5 % identical (2,321,902,638 of 2,566,533,768 cycles), 5 of 10 logs with any divergence.
First divergence: script-psg-edges, cycle 8054100, psg1 - ours 15, the oracle's 0.
Test ROMs
No community test ROM suite exists for this chip yet.
Analog stage
Not measured yet. This stage is a placeholder, not a result.
Driver coverage
The shipped driver reaches 4 of the chip's 10 voices.