Summary

This is a full featured SAW Core VCO. Sine, Pulse, Saw waveforms available with multiple modulation inputs and oscillator sync.

All waveforms are derived from a simple saw wave core using a JFET.

This VCO is compact, filling an 8HP space, but has comfortably spaced front panel controls for ease of operation.

It can be customized to provide triangle instead of sine if needed with one simple resistor change.

IMPORTANT NOTE

This is a PCB and Panel set only. A set of 2 high quality PCBs and 1 front panel ONLY are included. You will need to purchase your own components and build your own module. Comprehensive build instructions and BOMs are provided to help you source the components needed and we even provide links to shopping carts to simplify sourcing those components. Some product photos above show COMPLETED build.

8080-VCO used in patch with SEM

Features

• Saw core VCO
• Pulse, sine and sawtooth waveforms
• 1V/octave input + variable Linear FM CV and variable Exponential FM CV
• Adjustable pulse width and variable PWM CV input
• Hard sync input
• Easy to calibrate and customize
• Only 3 ICs
• Accurate tracking and excellent temperature stability
• 8HP Eurorack with our panel

Documentation

Comprehensive documentation, parts lists are provided in the documentation link for building, testing and calibrating the module.

A note on accuracy

If you want a highly accurate tracking VCO, please ensure you use very well matched transistors and also glue the thermistor and the two transistors together. The slight differences in temperature coefficients of the transistors can make the oscillator difficult to tune. If you don't need a highly accurate oscillator, you can use any transistors and even use a resistor instead of the thermistor. Here's a comment from one of our builders of a similar VCO:

"I ended up swapping the transistors from some I got in a Mouser order vs the ones I matched from a Chinese retailer. Found some that matched less then 1mv difference and Low and behold, I can tune it now!" From Dayne, Grand Forks, BC.

So: you choose.