Anti-aliased hard sync oscillator with true quad-unison

Tim Kleinert · Last edited by Tim Kleinert on Sun Apr 27, 2014 4:46 am; edited 1 time in total

This is an uncompromisingly ambitious (and thus unfortunately expensive) building block that demonstrates a robust solution to the following problems:

How to derive all classic waveforms simultaneously from a single oscillator (without resorting to trivial waveshaping methods with produce aliasing).

How to generate clean oscillator hardsync sweeps without aliasing.

How to create a true multi-oscillator unisono of a given complex waveform (without resorting to cheating via "chorusing" tricks).

This building block generates the classic waveforms (saw, tri, pulse with PWM) simultaneously, with low end boost for a fatter sound, anti-aliased hardsync sweep functionality (finally!), and true unison quadrupling of the resulting waveform with detune control.

It works by generating the desired waveform at a very low fixed frequency and then bandlimiting and resampling it at the desired pitch to avoid foldbacks. The resampling is performed by 'abusing' a delay-line, whose infamous and documented "readout bug" will unfortunately introduce subtle harmonic distortion into the sound. But by keeping oscillator levels high, it's quite OK. Way better than that horribly inharmonically aliasing standard G2 osc sync .

As mentioned, the circuit is hideously expensive (half a DSP). So, if nothing else, at least it's a proof of concept that these things are possible on the G2.

But if you're looking for clean sync sweeps and powerful unison for your no-compromise monosynth lead patch -here you go.

UnisonSyncOsc_TK.pch2

Description:

No compromise oscillator building block providing all classic waveforms simultaneously with low-end boost, anti-aliased hard sync sweeping, and true quad unison; Warning: expensive!

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UnisonSyncOsc_TK.pch2

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