Voltage Controlled Oscillator Tutorial
- 1). Turn the synthesizer and amplifier on, and turn the amp's loudness control all the way down. Connect the VCO to your amplifier by plugging an audio adapter cable into one of the output waveform jacks. Set the VCO's frequency by turning the control knob to about the middle of its range. Turn the amplifier's loudness control up until you hear a tone at a comfortable listening level.
- 2). Unplug the cable going to the VCO and try its other waveform outputs. A typical VCO has sine, triangle, pulse and sawtooth waveforms, all of which have different amounts of harmonics and produce sounds ranging from soft and mellow to bright and buzzy.
- 3). Connect a patch cord from the synthesizer's keyboard to the VCO's control voltage input. It may have more than one input. Look for one marked 1 volt per octave. Press the keyboard's middle C key. This should change the VCO's pitch, but the pitch will probably not be middle C. Turn the tuner on, and adjust the VCO's coarse and fine frequency controls until you obtain a middle C.
- 4). Play a melody on the keyboard. If you adjusted the VCO correctly, the melody will be in tune.
- 5). Turn the LFO rate down to a low setting. Find another frequency control input on the VCO and connect a patch cord from a sine or triangle LFO output to the VCO. You should hear the pitch slowly changing. Change the LFO rate and amount until you get a smooth vibrato. Turn up the amount and you should hear a wild, siren-like warble. You're controlling the oscillator's pitch with the keyboard and the LFO combined together. The keyboard provides a basic note voltage, and the LFO produces a rapidly repeating voltage. The net result gives you notes with the warble superimposed on them. Turning up the LFO's rate all the way should give you a gong-like metallic sound.
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