Roland TB-303 Clone
Exact copy of original 303 circuit, utilising original semiconductors including BA662, 2Sk30 and 2SC1583.
Original sequencer and firmware are omitted, replaced by MIDI interface and PIC micro for oscillator control. Power supply has DC/DC conversion like original allowing operation from 6VDC. Work has already been done on replacing rare semiconductors with modern equivalents. BA662 now has a drop in replacement which is a custom pin compatible device.
2 sample files with some delay effect - secondary note in background comes from turning accent pot.
Demo 1 triangle wave 400K
Demo 2 square wave 500K
My 303 has been through many revisions and new layouts. The most versatile was a rack mount version. This had the benefit of midi channel selection, sub oscillator and filter FM.
rack mount version