YAMAHA DX27 FM Vintage 80's Polyphonic Digital Synthesiser W/ MIDIYamaha DX27 Vintage Digital FM Synthesiser. The DX27 is a wallet friendly source for those 80's Yamaha DX sounds! It is basically a full sized keyboard version of the DX100. Like all DX's it uses (FM) Frequency Modulation synthesis. It's not the easiest form of synthesis to program but can result in some excellent sounds. It is most renowned for its great analog bass sound (Patch #01) that is awesome for techno, house, jungle, and acid music styles;