Yamaha released two classes of plugin boards, the PLG100 and newer PLG150. PLG100 boards will work in newer synthesizers such as the Motif ES, but voice data and/or patch storage may not be right.
PLG150-AN: Analog physical modelling based on the AN1x synthesizer engine. Adds 5 notes of polyphony.
PLG150-AP: Acoustic piano with 29MB of waveform data and 32 patch presets. Adds an extra 64 notes of polyphony.
PLG150-DR: Drums with 22MB of waveform data. Adds 80 drum kits and 32 notes of polyphony.
PLG150-DX: FM, adds 16 voices of 6-operator FM synthesis to polyphony. Updated version of the PLG100-DX.
PLG150-PC: Latin groove factory with 19MB of waveform data. Adds 80 Latin drum kits and 32 notes of polyphony.
PLG150-PF: Piano, with 29MB of grand piano waveform data and 32 patch presets. Adds an extra 64 notes of polyphony plus effects.
PLG150-VL: Virtual acoustic, adds one voice of physically modelled wind instrument sounds. Updated version of the PLG100-VL.
PLG100-DX: FM, adds 16 voices of 6-operator FM synthesis to polyphony.
PLG100-VH: Vocal harmony with real-time voice effects including vocoding and gender-bending.
PLG100-VL: Virtual acoustic, adds one voice of physically modelled wind instrument sounds.
PLG100-SG: Formant singing (called "formant synging" in the documentation). This board was the predecessor to the Vocaloid software and was only available in Japan.
PLG100-XG: Contains an XG compatible sound set. Adds 16 parts of multitimbrality and 32 voices of polyphony.
yamaha plg100-vh ($125.27)
Yamaha VL PLG card ($349)
YAMAHA plg150 dx plug in board ($601.06)
Yamaha PLG150-VL Virtual Acoustic ($187.18)
Yamaha PLG100-VL ($160.44)
Yamaha PLG150-PF ($185)
Yamaha PLG100-VL ($259)
Yamaha PLG150-PF Piano Expansion Board ($334.99)