'There are 21 preset sounds, all of which sound pretty silly. Fortunately, Yamaha included a section called "Digital Synthesizer" which is essentially a manual editing mode. In this mode, six sliders at the top right of the instrument allow you to shape DX/FM sounds. It is a very limited and simplified means of FM synthesis, but for many users this freedom from the complexity of having to attempt to craft FM sounds could be quite fun! The WAVE slider steps through a few very basic waveforms. The SPECTRUM slider is akin to a DX's frequency setting. The MODULATION is more of a timbre/brightness control that renders the sound from dull to bright, which is almost like filtering. The ATTACK and DECAY sliders both control the characteristics of the envelope. There is also a VOLUME slider which controls the output level of the synthesizer section.'
