Yamaha DX27The Yamaha DX27 is a full sized key version of the Yamaha DX100. It was released in 1985 and manufactured in Japan. The DX27S is the same synth, with built in speakers, stereo output, chorus fx and internal power supply.KeyboardThe DX27 features 61 unweighted full sized keys without velocity or aftertouch..MemoryThe unit features 192 presets, 24 user presets.SoundsThe DX27 is most notable for its "solid bass" sound. This sound was also shared by other 4-op FM synths, such as the FB-01, DX21, and DX100.