This is your basic 100 sounds/rhythms keyboard(I just can't call it a synth). It has 49 mini-keys and built-in speakers that are in stereo. You should probably use the headphone/aux out because the plastic its made out of likes to resonate when you play more than one note simultaneously with certain sounds. The cool thing about this keyboard is the dual mode. It comes on when you turn the keyboard on and is on sound 00, "piano". To set the sound for the dual voice, hold its button down and punch in the number of the sound you want. When the dual voice is on, your polyphony drops from 8 to 4. There is a numeric keypad to type in your sound/rhythm number. There are also + and - buttons to do this as well. These are also used to transpose the keyboard +/- 12 half-steps. I sold this off with my Casio CA110(see the review) for a total of $40, then bought a Yamaha DX-7 for $214!
Comments About the Sounds:
You can get some cool sounds by using the dual voice feature especially doubling one sound or mixing related sounds.