AD Multi VCO

Handmade analog rich sounding oscillator combined with a waveshaper and a linear AD envelope

100% Handmade through hole Radical Frequencies AD Multi VCO
Vintage, rich sounding oscillator combined with a waveshaper and a linear AD envelope.
There are multiple outs and a main Wave Out that can be voltage controlled via wave CV input jack to change the waveforms. As a result, you can randomise your sound by using this CV input with a sequencer, an LFO or any modulation source or even perform audio rate modulation with another VCO and make FM style sounds.

Waveforms : saw, square, pulse, double pulse, triangle pulse.

The separate outs are in reverse phase than their versions that appear in the main wave out.
PW A pot and PW D knobs are those for shaping the pulse width, those knobs are also the Attack and Decay when the module is in AD ENVELOPE MODE
PW A and PW D are voltage controlled and the attenuators of the amount of CV amount, are the knobs A CV and D CV .
The Sync knob is for attenuation of the sync input jack of the VCO,
The Wave knob is changing the waveforms and there is a wave CV jack input too.

The VCO is capable of performing Exponential FM with CV input and attenuator.
Linear FM with CV input and attenuator with a switch for DC or AC input.
There is a volt per octave (V/O) jack input for tracking and the VCO will deliver 5-6 octaves of accurate tracking.

The knob that selects between VCO and AD envelope function, is an offset that can be tweaked manually but there is also a CV input provided for this functionality, allowing for even more complex results.
When the knob is at AD envelope mode, the only available waveforms are the saw and square waves.
The Attack Decay envelope has a gate input and its output appears at the triangle pulse out, the PW A is the attack and the PW D, is the decay.
Turning the knobs anti clockwise, increases the amount. The A CV is the Attack CV, the D CV is the Decay CV.

In conclusion, the module can be an oscillator and envelope simultaneously, but the VCO can only produce the saw and square outs.
When in AD Envelope mode, a trigger is required at the Gate input.

When in VCO mode:
Saw is the classic wave of the core of oscillator.
Square out is not a perfect square but is musical and warm.
Pulse can be pulse width modulated by the PW A knob and A CV .
The triangle pulse can be used for making brassy sounds as it can be used without filter just by adding and subtracting harmonics when tweaking the PW A and PW D pots, or the A CV and D CV inputs.
The double pulse wave is a 2 pulse wave with a double pulse width modulation.
That’s the dream of every PWM synth lover out there!
The PW A and the PW D knobs, control the pulse width modulation for each of the 2 pulse waves that are connected to form this double pulse waveform.

The core of the oscillator is a pure discrete saw core of classic American east coast style sound, and it needs at least 25 minutes to warm up.

The sound is fat and very good for bass sounds too as you can trig the phase of the sync input for stable phase (phase re-trigger) in fast bpm bass lines with 1/16 notes.

About the behaviour of the waveforms with pulse width modulation, it must be mentioned that the waveforms are frequency dependent so it could be a good idea to send your volt per octave not only to the tune of VCO but to the A CV and D CV inputs as well. For this reason there is an internal normalisation that connects the V/O jack input with both A CV and D CV and by turning these knobs, fully clock wise, you increase the tracking stability across all waveforms.
If you want to control with some modulation source the A CV or D CV then the normalisation cuts the V/O connection, that means the tuning is working differently for the PW waveforms and you can achieve interesting de-tuning between the PW waveforms and the core waveforms, so experiment and discover varying amounts of detuning, in a single VCO module!
(Important note: when you don’t have any jack connected to v/o input or any of the A CV and D CV inputs the knobs A CV and D CV must be fully closed )