Kilpatrick Audio - K3021 Master VCO


This excellent analog oscillator is based around a triangle core and has been built around discrete transistors, providing for amazing sound and high stability. What makes the 3021 extra special is the use of complex wave shaper and a triple PWM circuit for a rich and living character. An finally the VCO features voltage controllable crossfading between the waveforms and linear FM.



The K3021's tremendous frequency range spans from 60 seconds per cycle to 15kHz. The frequency setting is done with coarse and fine tuning potentiometers and a switch alternates between VCO or LFO mode.
Voltage control of frequency is made possible via an 1V/octave input and a linear FM input with attenautor. A temperature compensated exponential converter with matched transistors provides for best tracking. A sync input is used for hard oscillator synchronisation.

In the K3021 a triangle is used as the core waveform from which the sine and the sawtooth are derived. Afterwards they are processed by a complex waveshaper generating single, dual and even triple pulse wave modulated waves, sounding sound way more complex and living than a conventional PWM.
The pulse width(s) are set manually with PWM Offset and via the PWM modulation input which can be attenuated. The wave forms are available at two different outputs:

  • BLEND: This parameter blends from a selectable waveform (sine, triangle, sawtooth) to pulse which is done manually with Blend Offset and with a CV at the Blend In socket. The VCAs used for the blend function are high-quality with ultra-low distortion. The wave which has been selected with the Wave potentiometer is displayed with a LEDs.
  • PULSE: At the Pulse Out only the output of the pulse shaper are emitted. The Pulse switch selects between a single, dual or triple PWM which is visualized with LEDs as well.


The 3021 Master VCO is based on the design of the 3021 Dual VCO but it was completely re-designed to replace discontinued or hard to find parts.


inputs: 1V/oct (CV IN), FM, PWM CV, Sync, Blend CV
waveform outputs: blend out, pulse out


3U Eurorack module, 18HP wide
current draw: 90mA at +12V and 50mA at -12V

0.197 kg
Article Number
Status: The Article can be picked up at 4 p.m. if ordered before 12:00 noon / Article is ready for shipment
availability ? immediately available
€ 19% VAT excl. €250.42 € 19% VAT incl. €298.00
Excl. 19% VAT, Excl. shippingLieferzeit 2-3 Tage