The POLY-SYNTH SECTION: a 7-note polyphonic synthesizer with filter, pitch, envelope, and portamento controls.
It features two (detuneable) oscillators per voice so it's good for thick pads.
Also features LFO, filters and ADSR envelopes.
t has a built-in sustain and the Tremolo and Ensemble chorus effect also apply to this section.
The SOLO SYNTHESIZER SECTION is a single VCO driven mono-synth, similar to the CS5.
It has pitch, waveform, filter, volume, envelope generator and portamento functions.
The waveform slider sweeps from square to saw wave, with separate PWM control.
It has a rich tone and stable pitch across it's six octave range.
The PRESET STRINGS section constitute three sounds - those sounds are sublime though, very similar to the best of the string synths, (such as the Arp Solina/Omni or the Logan String Machine)
The ORGAN SECTION offers a full range of stop levers from 1' to 16', percussion levers with adjustable decay, and controls for overall sustain, brilliance and decay.
This gives you quite a lot to work with in the way of synthesis.
The organ's sound is FM based and offers a very good B3 emulation.
This is one of the early implementations of Yamaha's FM technology, concurrent with the GS-1/2 development platforms which eventually led to the DX series.
Vibrato and Tremolo controls.
The sound is reminiscent of the typical 70's rock organ, especially with the Ensemble chorus effect in use.
It also has an external tonewheel cabinet output!
The keyboard's after-touch can control the vibrato, tremolo, and brilliance effects.