The Roland Juno-60 is a popular 61-key polyphonic synthesizer introduced by Roland Corporation in September 1982, as a successor to the similar Roland Juno-6, which had been on the market since February that year. Like its predecessor, the Juno-60 is essentially an analog synthesizer with digitally controlled oscillators.
The Juno-60 synthesizer is a six-voice polyphonic synthesizer. The single digitally controlled oscillator (or DCO for short) per voice gave the Juno-60 a high degree of stability in maintaining tune; most analogue voltage-controlled oscillators (VCOs) of the time would tend to drift in pitch and require re-tuning of the oscillator. The DCO provides sawtooth and square/pulse waveforms as a sound source, in addition to white noise and a square-wave sub-oscillator pitched one octave beneath the key played. Both of these additional sources can be mixed in with dedicated sliders.
The filters and envelope on the Juno-60 rely on control voltages sent by depressing the keys on the keyboard and were thus analogue. The Juno-60 features a rather distinctive-sounding 24 dB/octave lowpass filter with resonance. Unlike other VCFs of the day, the Juno-60's is capable of self-oscillation and thus could be used to some degree as a tone generator in and of itself. The filter section also features controls for envelope amount and polarity, LFO modulation, and keyboard tracking. In addition, a three-position non-resonant highpass filter is provided to thin out lower frequencies.
The Juno-60 provides a single triangle-wave variable-rate LFO for modulation options. This is routed into the DCO to create pitch vibrato and pulse-width modulation, plus into the lowpass filter to generate a tremolo effect. All three choices can be used simultaneously, each with their own individual depth settings. The LFO can then either be triggered manually by the left hand using a large button above the pitch bend lever or set to engage automatically whenever a key was pressed. The LFO also features a slider to adjust a delay time for when it will be triggered automatically.
The signal is then sent through a voltage-controlled amplifier (or VCA) and a simple four-stage ADSR filter envelope. One unique feature of the envelope is its ability to also control the width of the pulse waveform.