- 5 octave velocity sensitive keyboard
- 4 operator FM synthesizer (the same as TX-81z)
- 200 preset and 100 programmable patches
- 8 note polyphony, 8 part multitimbral, mono mode, portamento is not available
- 16 x 2 line LCD display
- built-in delay effects, short and long delay, the decay rate can be adjusted with a wee knob in the back panel
- "auto performance" mode for left hand accompaniment with 43 different patterns that can be transposed from the keyboard
- arpeggiator (no possibility to edit)
- dynamic midi allocation
- Independent 5-parameter envelope generator for each operator
- batteries inside as a alternative power source
- demo song
Yamaha DS-55

YAMAHA Manual service - Manual for DS-55 as well as for most of FM synths