Grant Middleton master class - Smooth SyncGrant Middleton master class - Smooth Sync
I've always wanted to get the Moog Prodigy style of hard sync out of the Nord, but never realised the technical reasons why it couldn't be done.
That was, until I read Rob Hordijk's piece Fat Sound
It'd be an idea to read the section headlined 'sync' before attempting to understand this patch.
OK, Master Osc 'Sync on Transient' drives OscSlvC1. Its output is split, going to Mixer 3 (a simple oscillator source mixer) and Sync Signal Mixer. Sync Signal Mixer combined with Constant1, ensures that OscA1 and OscA2 receive their sync input pulses near the transient of OscSlvC1, not its zero-crossing point (thanks for that tip, Rob !). Now, you'll notice that I've actually got two synced oscillators here, whose outputs go to audio mixer 'Octave Saw'. By setting these input levels at exactly these settings, the square and sawtooth waves combine to produce a sawtooth wave of twice the fundamental frequency of the oscillators. This means that where there would usually be a zero-crossing, you actually have a transient: Exactly what we need to get that authentic vintage analogue response!
Pitch input 1 on both synced oscillators are set to exactly the same level, and are fed from the output of audio mixer 'Sync Control'. Its three inputs are a slewed constant called 'Sync Freq', an LFO (all waves provide interesting effects) and a short envelope. Knob 1 provides constant sync offset frequency, Knob 2 provides LFO depth and Knob 3 provides envelope depth.
The inputs to Mixer 3 are:
By muting inputs 2 and 3 in turn, you can hear the difference in nature between original sync and the new improved (IMHO) sync of this patch. This should help you add more authenticity to Prophet 5, Pro-One, Prodigy, etc. sync sound emulations.
