The instrument
The SY-20 is a 44 key, monophonic analog synthesizer, featuring 20 presets, portamento, LFO, resonant low or band pass filter, dedicated filter and amplifier (ADSR) envelopes, and a speaker. It was Yamaha's last analog synthesizer before the company turned to digital FM synthesis. It was only sold in Japan.
Details
The 20 presets of the SY-20 can be controlled in a variety of ways: via the VCO, VCF and VCA sections with foot position, cutoff, resonance, noise, BPF, LPF and LPF+BPF, 2-way ADSR, portamento, sustain, main brilliance and aftertouch. All sections can be activated individually and combined with the selected preset. The LFO can be used to modulate all three sections for pitch, filter and tremolo effects. There is also portamento and a transpose control with an octave in semitone steps. The VCO offers an oscillator with square and saw waveforms that can be mixed. The pitch can be adjusted from 2' to 32'. Pulse width modulation and white noise are also available. The VCF offers low-pass and two band-pass modes. The cutoff and resonance controls are accompanied by ADSR envelope controls. The VCA section offers the usual ADSR controls. The 44-key keyboard supports aftertouch, which can be sent to the VCF, VCA and LFO to add filter, volume and modulation effects at the touch of a button.