Like many Yamaha devices from 1983 to 1987, the PS-35 uses the FM synthesis for sound production.This was put into effect on the PS-25, 35 and 55 by combining several singular chips with open, tamper-friendly architecture.
Same thing goes for the drum sound production, which is executed by a control CPU and a ROM chip with stored PCM samples.
The great range of functions and separate volume controls for the components make the devices from this series enormously versatile. Up to now I've implemented the following modifications:
- "Synthesizer" matrix consisting of 6 switches for manipulating the FM sounds
- "Drum" matrix consisting of 6 switches for altering the drum sounds
- Tempo fine controller
- Mute switch for all drums