The instrument
The Yamaha CP 30 piano was introduced in 1976 at the same time as the larger CP 70, but with a different design. In the CP-70, the sound is produced by striking hammers on taut strings; piezoelectric pickups convert the tones into electrical signals. The CP-30 is an electronic piano with an analogue tone generator and can also be described as an analogue synthesizer.
Details
The CP-30 piano has 76 keys and is touch-sensitive. Thanks to dual tone generation, two tones can be mixed and detuned from each other using a pitch control. The two sound sets with tune, decay, tremolo and voice controls for each sound and the balance control between the two sets can be detuned for chorus and other variation effects. Each set has 4 selectable sounds: piano 1-3 and harpsichord. Attack and decay parameters can be set simultaneously using the decay control, just like the ADSR envelope of a normal synthesizer. The two tone generation systems each allow independent decay control, for example by using the first tone generator for the attack part of the sound and the second for the sustain.