YAMAHA YM chips numerical classification

YM21xx - YM39xx

Yamaha has developed tons of sound chips, and they often bother chip researchers since many different lines get snarled up in close numbers. So I tried to ravel them on the following chart.

FM unique FM 4op FM 2op FM 4op with SSG/PCM SSG other sound generator DAC sound effector not for sound output unidentified
YM21280 (OPS)         
YM21290 (EGS)         
        YM2148 (MKS) 
    YM2149 (SSG)     
    YM2149F (SSG)     
 YM2151 (OPM)        
 YM2164 (OPP)        
YM2198 (KAS)        
   YM2203C (OPN)      
        YM2270-2 (ROM) 
FM unique FM 4op FM 2op FM 4op with SSG/PCM SSG other sound generator DAC sound effector not for sound output unidentified
     YM2409 (GEW)    
       YM2412 (ADF)  
  YM2413 (OPLL)       
  YM2413B-F (OPLL)       
 YM2414B (OPZ)        
   YM2608 (OPNA)      
   YM2610 (OPNB)      
   YM2612 (OPN2)      
        YM2702-D (key scanner) 
FM unique FM 4op FM 2op FM 4op with SSG/PCM SSG other sound generator DAC sound effector not for sound output unidentified
        YM3023 (floating S/H) 
        YM3039 (AV controller) 
       YM3413 (LDSP)  
       YM3414 (digital filter)  
         YM3422B (ESI)
     YM3423 (GEW3)    
     YM3424 (KPU)    
       YM3433B (ALCDF)  
       YM3433B-D/F (ALCDF)  
       YM3434 (ALCDF compatible)  
        YM3436D (DIR2) 
        YM3436B (DIR2) 
        YM3436D (DIR2) 
        YM3437B (DIT2) 
        YM3437C-D/F (DIT2) 
   YM3438 (OPN2C)      
    YM3439 (SSG?)     
FM unique FM 4op FM 2op FM 4op with SSG/PCM SSG other sound generator DAC sound effector not for sound output unidentified
  YM3526 (OPL)       
FM unique FM 4op FM 2op FM 4op with SSG/PCM SSG other sound generator DAC sound effector not for sound output unidentified
        YM3802 (MCS) 
        YM3805 (CD player controller) 
        YM3805-H (CD player controller) 
YM3806 (OPQ)         
  YM3812-F (OPL2)       
        YM3818 (digital signal processors) 
        YM3901 (ADA) 
        YM3934 (peak meter modules) 

* Yamaha has used their integrated circuits for frequency modulation synthesis since the first models called GS1 and GS2 which consists of 55 ICs. Later ICs were decreased to 5 or 6 on CE20 and CE25. But I cannot find any informations about chips they include.

* Numbers before YM21280 were also used for home keyboards etc. But line-up and functions are almost unknown. So I started from YM21xx series. Some of you might have noticed that YM chips change directional character in every 100 (or 200) unit. Here're my complements:


YM21xx numbers could be called the basic models of Yamaha's one-chip synthesizers from squarewave synthesizer to rhythm machine. However, YM21280, the core of DX-7, doesn't work independently yet. It needs YM21290 as the envelope generator. This set is the direct ancestor of one-chip FM synthesizers commencing with YM2151.

YM2149 is known as the modified version of General Instruments AY-3-8910. It looks strange that a clone chip appeared in YM21xx range filled with original chips. In 1983, Yamaha played primary role at MSX standard development. And I guess Yamaha wanted to develop entire sound part of MSX by their hands since they advocate that developing and producing best devices by themselves is their policy for providing better sound making. In fact YM2148, YM2149 and YM2151 first appeared on their MSX computers and a sound expansion called SFG-01. Incidentally, I guess MKS is short for "MIDI interface and Key Scanner."

YM2151 is Yamaha's first single chip FM synth, was implemented not only to Yamaha's FM synth keyboards such as DX-21 (1985), DX-27, DX-100 but also to arcade games/home computers. In 1984 Atari acquired legal right to use it as their arcade components. (on the contrary, Yamaha didn't allow Atari to use it for home computers.) Their "Marble Madness" is known as the first video game using YM2151, then Sega, Namco and Konami followed.

YM2164 is almost identical to YM2151. Perhaps the only improvement is multi-timbre MIDI input support. YM2164 first appeared on the SFG-05 (an advanced version of the SFG-01 which added MIDI input) and later used for the FB-01 which was designed as a standalone MIDI module version of the SFG-05. It was also provided to Korg and they used it for the DS-8 (1987) and the 707 (1988).

YM2154 was made for RX-15, so perhaps it's a PCM sound chip for rhythm samples.

YM2163 is for toy keyboards such as Testron CL-60910.
Christian Oliver Windler analyzed that has four squarewave channels with different pulse widths and envelopes + e-bass + rhythms. So it might be improved version of SSG.

YM2198 used in YP-40 is perhaps FM synth chip for Clavinova series.


YM2203 is known as one of the most famous FM synth chips in arcade, as well as YM2151. However, in the beginning, YM2203 was used for Japanese hoby computers such as PC-6001mkII SR and PC-6601SR (1984). YM2270 is a ROM chip including instructions to control YM2148 and YM2151. So YM22xx might have been assumed for home computers. Most of YM21xx-YM22xx appeared during 1983-1985.


Here you can find advanced/cut-down variations from YM21xx range. Most of them appeared during 1986-1987. YM2409 and YM2412 were used for Yamaha's first sampler called TX16W. YM2409 generates sample sound from the wave memory, and YM2412 filters it digitally.

YM2413 is the cheapest FM synth chip among YM family which has been used for the FM Sound Unit of the Sega Mark III (1987) at first. This is the last YM 4 digits sound chip which is still on stream.

YM2414 found in TX-81Z (1986) and V-2 (1987, also known as DX-11) can be regarded as a progressive edition of OPM. YM2151 uses sinewave as an only basic waveform. But YM2414 allows you to select 8 different waveforms.

YM2420 used in SHS-10 shoulder keyboard is a chip quite similar to YM2413. It has six tone channels + some rhythm channels.


Apparently YM26xx was prepared for OPN variations. YM2608-YM2612 have additional PCM/ADPCM part(s) as well as OPN compatible parts. YM2608 was mainly used for PC-8801/9801 series. YM2610 was mainly for arcade. YM2612 used in Sega Genesis/Megadrive and FM-Towns removed SSG channels. So it isn't 100% OPN compatible. Most of them appeared during 1987-1988.


Almost no informations.


Major FM synth chips such as OPL/OPM/OPN need YM301X as their digital to analog converter. So YM30xx development must have been started along with YM21xx series. In many cases YM3012 is used for YM2151, YM3014 is for YM2203/YM3526 and YM3016 is for YM2608/YM2610. YM3020 is found in Yamaha AD-808 (8 channel A/D converter).


Numerically YM34xx is located immediately after YM30xx. But maybe it's far later series.

YM3413, perhaps a type of sound effector chip, is found in PSR-330 portable keyboard (1997).

YM3414 is in CD players such as CDP QUATTRO II (1988).

YM3424 is in CLP (Clavinova) series, might work as a part of piano sound generator.

YM3433 is two-channel 8x over-sampling digital filter.

DIR of YM3436 means Digital format Interface Reciever.

DIT of YM3437 means Digital audio Interface Transmitter.

YM3438 and YM3439 seem CMOS revisions of OPN2 and SSG. So YM34xx range might have focused on CMOS process. YM3438 is known as a sound chip of Sega System 18/32 (1989) and FM Towns II (1991). Also YM3439 is known as a sound chip of Atari Falcon030 (1993).


YM3526 was born at least by 1985 and can't be later than YM3438 and YM3439 etc. It means that YM35xx-YM39xx development was started not after YM34xx. The time-line after YM35xx seems to have proceeded alongside of YM30xx-YM34xx. YM3526 is the first model of cheaper two operators series. Yamaha seems to have announced OPL as their second one-chip FM synth. First it's appeared in Nichibutsu or SNK arcade games.


No informations.


YM38xx expanded into wide range, so I cannot find any directional characters.

I guess that MCS of YM3802 means MIDI Contol System. It appeared at least in 1986, and is found on MIDI interface cards for X68000 etc.

YM3804 and YM3807 are found in SPX90II, a multi sound effector released in 1987.

YM3806 is in PSR-70 portable keyboard (1987) featuring eight FM tone channels + some rhythm channels. According to
Sonic State, the FM tones are derived from DX-7.

YM3812 is an advanced version of YM3526 which allows you to select 4 basic waveforms. In 1986 it first appeared on arcade games, and later adopted to the famous Adlib sound card. Some sources state that there was a compatible chip called YM3814. But I cannot find farther informations.


There're few informations. YM3901 is found in AD-808 (19xx). I guess ADA means Analog to Digital Alternator. YM3931 seems sample sound generator or something, used for Seibu Kaihatsu's arcade games since the Air Raid (1987).

list of references:

Ranger Audio Enterprises
BEFiS sound chip list at [Hall of Fame] section
Yamaha CX5M(II) music computers
Vortexions page on sound chips


Hex125, Kayama and Stiletto.

Written by Hally (Dec.4th 2003)