Lab Seven modules for VCV Rack

All modules are available for free and open source*. If you like them,
please consider making a donation. Any amount is welcome. Thanks!

*licensed under Creative Commons Attribution-NonCommercial-ShareAlike 4.0
International Public License, see CC website and LICENSE.txt

MK1/2 modules -

Algorithm modules -

VCO-3340 Oscillator

The first Lab Seven module: An extended version of a classical VCO from a well-known 80s synthesizer. Comes with standard blue and 'classic gray' skins (simply rename svg files to change skins).

User interface features

• RANGE
• RANGE knob: Selects the pitch of the entire VCO in octave steps
• RANGE Input: Extends the range of the knob by +- 3 octaves from 128' to an upper limit of 0.5'.
• -3V: -3 octaves
• -2V: -2 octaves
• -1V: -1 octave
•  0V: No change
• +1V: +1 octave
• +2V: +2 octaves
• +3V: +3 octaves
• Comment: The idea is to equip another module with a (-3, -2, L, M, H, +2, +3) switch or modulate the range input for arpeggiator-like effects.
• Comment: Maximum pitch is limited to 45% of the current sample rate (example: 44.1kHz -> 19,8kHz) with a hard threshold of 40kHz.
• MOD
• MOD fader: Selects the amount of pitch modulation.
• MOD Input: +- 5V -> +- 2.25 octaves of pitch modulation (like the original synth)
• V/OCT: Determines the pitch of the note to be played.
• PWM (pulse width modulation of the square waveform)
• PULSE WIDTH fader: Scales the amount of PWM. The effect depends on the selected PWM source.
• PULSE WIDTH selection
• LFO: Input +- 5V -> 10% to 90% pulse width
• MAN: Manually sets pulse width, ranging from 50% to 90%
• ENV: Input 0V to +10V -> 50% to 90% pulse width
• Source mixer
• Waveforms: Square (with PWM), sawtooth, triangle, sub oscillator (3 modes), coloured noise
• Individual waveform outputs are unattenuated. Faders only affect the MIX output.
• SUB OSC mode selection (SEL) input options
•  0V: Manual selection
• +1V: 1OCT DOWN
• +2V: 2OCT DOWN
• +3V: 2OCT DOWN with 25% pulse

Algorithmic (internal) features

• Internal resolution: 192kHz
• VCO algorithm: BLIT (band limited impulse train) + leaky integrator
• Impulse: Original 3340 impulse reconstructed by Blackman-Harris kernel + leaky integration
• Coloured noise: High quality sample loop @192kHz
• Resampling/anti-aliasing: Windowed sinc interpolation