Guru Gara Synth 3340 VCO

DIY 3340 VCO (Voltage Controlled Oscillator) (PCB, Front Panel and AS3340)

This is a basic circuit design from CEM3340 datasheet. It was widely used in the 80s by many synth manufacturers such as Roland and Oberheim. AS3340 is included in this partial kit. Front panel is also made out of pcb and it is hand printed in 2 colors. This is a 10HP eurorack synth module. It’s an easy build.

Core circuitry can generate 3 different wave forms (Square, Triangle and Ramp) and it has a triangle to sine converter. It has hard sync and soft sync inputs, Linear Frequency Modulation input and also 1 volt per octave input with solid tracking. Pulse width can also be adjusted for square wave and it can also be modulated with external cv. When a jack is inserted in PWM CV input, the PW potentiometer works as CV amount.