In 1998, after several years without producing a single FM synthesizer, Yamaha released a new FM powerhouse...the FS1R. This little beast is far from your average FM synthesizer. Not only is it an eight-Operator variant, as opposed to the six- and four-Operator FM of the DX/TX lines, but it also features a new technology called Formant Shaping Synthesis. Formants are the spectral patterns making up the sounds of human speech. This allows for the creation of vocal like timbres but can also be applied in many different ways to create incredibly unique sounds that you won't find on any other synths.

DX7 aficionados will like the fact that the FS1R has almost complete compatibility with 6-Operator FM synths: you can send, via MIDI, a patch from a DX7, for example, and the FS1R will convert it to an identical-sounding patch in the new synth. A lot of the preset Voices actually come from the DX7's library. It's also possible to program sounds from DX7 sound charts, finding an algorithm that has an equivalent layout to the DX algorithm and turning off the unwanted Operators.