Wizardry: Oscillators

Content courtesy of John Papiewski

New Timbral Oscillator (NTO)

Pro: Very stable, versatile, accurate oscillator. Kiss pitch drift good-bye forever. Wide continuous-sweep range with no range switching. VC glide, VC linear modulation depth. Calibrated 1v/oct inputs, and attenuated VC input. Soft sync. VC variable wave output sweeps from saw to sine to rectangle. VC portamento input.

Con: No hard sync, variable wave output is AC coupled, so useful pulse waves are limited to audio range. The name is a little silly at this point, it was 'New' in the 80's when it was introduced. The sinewave has a slight audible distortion in it - audible in the lower registers.

Wizardry: patching a waveform back into the attenuated VC input gives interesting results. The oscillators respond to negative control voltages, allowing real vibrato, and letting you extend the low end of the frequency range if you have a negative bias source handy.

For maximum pitch stability/tracking, don't do any critical tuning till at least several minutes after initial power-up for the day. How do you know the stability is good? Mix and tune two oscillators together so the beat frequency is very low, say, 1/10 Hz. Leave it this way for a couple hours. When you come back is the beat frequency any different?

Precision Oscillator (PCO)

Pro: Great 'mainstay' oscillator. Same accuracy/tracking as NTO but smaller and less expensive. Calibrated 1 v/oct inputs, plus attenuated VC input. Soft sync. Linear FM. High-low range switch for audio/LFO applications.

Con: No rectangular waveform, DC coupled sinewave or hard sync. If you want a square wave, get an NTO or patch any PCO output into a comparator.

Wizardry: see comments for NTO.

Quadrature Oscillator

Used mainly for quadraphonic panning; simultaneous sine-cosine output waveforms. Voltage-controlled LFO.

Useful for anything else? Neat 'hold' input freezes the state of the waveform when 'hold' goes high.

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