Yamaha made a large number of custom integrated circuits to perform functions in musical instruments and devices. Most of these were produced for personal keyboards or third-party devices, but some have appeared in Yamaha's synth products. Below is a selected list of Yamaha and other custom ICs that have been used in Yamaha synths. A much more comprehensive list can be found from Edward D|Tech here.
- TMC3490PH: A combination sample processing and 2-operator FM generator, used in the SY-22, SY-55, and TG-33.
- YM2128/21280: FM operations generator used in the TX7 / DX7 respectively.
- YM2129/21290: Envelope generator used in the TX7 / DX7 respectively.
- YM2151: Implemented Yamaha's 4-operator FM method which Yamaha put into a large number of products in the 1980s. This one was used as a tune chip in many 1980s arcade games.
- YM2164: 4-operator FM generator used in most of Yamaha's 4-op synths from the 1980s, including the DX-21, DX-27, and DX-100; also in the FB-01 and the FM module of the CX5m computer.
- YM2190-x: A series of sample ROMs used in th RX-11 drum machine.
- YM2414: 4-operator FM generator used in the DX-11 and TX81Z.
- YM3416: An effects processor widely used in Yamaha products between about 1987 and 1993, including the SY-22, SY-55, SY-77, TG-33, TG-100, and R100 drum machine.
- YM3802: A MIDI interface processor used in the RX-5 drum machine.
- YM7155: Sample processor and digital filter which forms the basis of the voice architecture for the SY-55, SY-77, and SY-99. Physically very large (128 pins).
- YMP706: Sample processor and digital filter used in the DX-200.
- TC170C120SF-003: Sample processor and tone generator used in the CS-1X.