As described by Synthrotek: 

"The VCO is an analog voltage controlled oscillator with a wide frequency range and 8 trackable octaves. 

It uses the Curtis CEM3340 reissue chip, which is famous for its outstanding sound quality. 

This kit is already partially made; the logic board (included) is pre-built, so the only board that needs to be soldered together is the control board. 

Everything that is needed to fully build the module is included in the kit." 

Features: 

Simultaneously available triangle, saw and square wave outputs 

Frequency range: 5Hz to 28kHz FM input and attenuation control PWM input and attenuation control 1V/o input, tracks 8 octaves 

Specifications: 

Width: 4HP 

Depth: 53mm 

Power draw: o +12V: 42mA o -12V: 31mA 

Includes power cable and module screws.