K3021 Master VCO

Triangle Core VCO with Waveshapers

Built on the success of the K3020 Dual VCO, the K3021 Master VCO offers a single channel oscillator based on this famous design. Completely redesigned to replace now hard to find parts, the K3021 uses a complete new triangle core design based around discrete transistors for an amazing tone excellent stability. Useful as both your main pitch oscillator and as a complex low-frequency signal source (LFO) the K3021 Master VCO is a workhorse module great for any system.

One of the features that makes the K3021 extra special is its use of complex waveshapers and pulse width modulation circuits to create unique timbres. You can select between sine, triangle and ramp waveforms for the WAVE section. These waves then feed into the triple pulse width modulator to create very rich pulse waves that have a much more lively character than a simple single-channel PWM. Choose from one of three PULSE output combinations for unique variations.

The BLEND and PULSE outputs can be used independently, or can be combined through the use of the ultra-low distortion blend section. Smoothly fade between the WAVE and PULSE waveforms either manually or with voltage control. By using the blend circuit especially with the LFO mode engaged, very complex modulation waveforms can be easily created.

Features and Specs:

• Eurorack (3U) form factor - 18HP width
• Master VCO with on board precision power regulation
• LED indication of selected switch positions and VCO core activity
• 1V/octave CV input - factory trimmed for 1V/octave response
• Linear FM input with level control
• Fine and coarse tuning controls
• Normal VCO frequency range: 2Hz to 15kHz
• LFO mode switch - period approx. 60 seconds to low audio range
• Temperature compensated exponential converter with matched transistors
• All-new discrete triangle-core and sine wave shaper
• Wave shaper with sine, triangle or ramp waveforms - switch selectable
• Pulse shaper with triple pulse width modulators for complete timbres
• Voltage controlled mixing between wave and pulse waveforms
• High-end blend VCAs with ultra-low distortion and linear control
• Sync input for hard syncing of VCO core
• PWM input with level and offset controls
• Blend VCA control input with level and offset controls - full deflection with 5Vpk-pk
• Blend output - output from the blend VCA containing wave and/or pulse waveforms
• Pulse output - dedicated output from the pulse shaper containing pulse waveform
• All inputs and outputs are tolerant of +/-12V
• All outputs drive 10Vp-p with 1K output impedance
• Requires +12V (90mA), -12V (50mA) - 16 pin Doepfer-style power cable used - approx. 1.7W total power consumption
• Designed and made in Canada using high quality parts.
• Warranty: 1 year

http://www.kilpatrickaudio.com/?p=K3021