Roland Juno-6, Juno-60 and Juno-106, plus the SH-101

Digitally controlled oscillators: analog sound, stable tuning

By the early 1980s the market was turning to digital synthesizers, but Roland had no commercially viable digital technology — and Yamaha had already secured exclusive rights to FM synthesis. Roland's answer was a low-cost analog polysynth to compete with the Prophet-5 and its own Jupiter-8.

The key was the digitally controlled oscillator (DCO): an analog oscillator whose frequency is set by digital circuits rather than a control voltage. Voltage-controlled oscillators frequently drifted out of tune; DCOs did not. One magazine called the Juno-6 the first analog polysynth you could carry onto a stage, switch on and play with complete confidence that it would be in tune. The trade-off was one oscillator per voice, which Roland compensated for with a sub-oscillator, a bass-boosting high-pass filter setting and a built-in chorus.

Juno-6, Juno-60 and Juno-106 compared

All three share the same voice: six voices, one DCO per voice with pulse, sawtooth and sub-oscillator waves plus noise, an analog 24 dB-per-octave resonant low-pass filter, a non-resonant high-pass filter, one ADSR envelope and one triangle LFO. The keyboards have 61 keys with no velocity, aftertouch or split. The Juno-6 listed at US$1,295 and the Juno-60 at US$1,795. The Juno-106 introduced Roland's left/right/push lever for pitch bend and modulation, later standard on Roland instruments, and was one of the first analog synthesizers whose parameter changes could be recorded and played back by a sequencer over MIDI.

The Juno chorus

The chorus is engaged with two buttons: mode I modulates slowly at 0.4 Hz, mode II at 0.6 Hz, and pressing both together gives an even stronger effect. It uses two identical bucket-brigade delay circuits (MN3009 and MN3101 chips), descended from Roland's 1976 DC-50 Digital Chorus. It is famously noisy, and it is also the sound most people mean when they say "Juno". Software versions of the chorus alone have been released since 2007.

Juno-106 and the later Junos

The Juno-106 was Roland's best-selling synthesizer until the D-50 later in the decade. Its filter is packaged in Roland's 80017 chip, a version of the IR3109 filter used across Roland's analog range; in 1985 Roland added the Juno-106S and the HS-60, versions with built-in speakers.

• Alpha Juno 1 and 2 (1985–1986): new programming and backlit displays, but seen as too expensive and hard to program.
• Juno-D, Juno-G, Juno-Stage, Juno-Di, Juno-Gi (2004–2010): affordable digital keyboards that share only the name.
• JU-06 (2015) and JU-06A (2019): compact four-voice digital models; the JU-06A switches between Juno-60 and Juno-106 behaviour.
• Juno-X (2022): a modern synthesizer with digital models of the Juno-60 and Juno-106.

The SH-101: Roland's monosynth of the same era

Roland made the SH-101 from November 1982 to 1986. It launched at US$495 (£249 in the UK), far cheaper than the digital synthesizers of the time, in grey and in limited red and blue editions. Roland marketed it as a keytar — an optional handgrip adds modulation controls and a shoulder strap, and it runs on batteries — but it was outsold by the Yamaha DX7 and only later became a staple of 1990s electronic music, particularly house.

Recreations include Roland's SH-01A Boutique (2018) and S-1 (2023), and a 2019 clone by another maker that adds MIDI and USB.

Junos and the SH-101 on a session

• Juno-6: no memory and no external control; treat it like a classic analog, writing down settings.
• Juno-60: 56 memories; its DCB port links only to DCB-equipped Roland gear unless you add a converter.
• Juno-106: MIDI, 128 memories and a portamento control; the easiest of the three to sequence.
• SH-101: sync its sequencer or arpeggiator from an external clock, or play it over CV/gate; its sequencer holds 100 steps.