A series of three polyphonic analog synthesizer models produced by Roland in the early-to-mid 1980s. These were introduced to be less expensive alternatives to Roland's flagship Jupiter synth, with the first model, the Juno 6, billed by Roland as being the first synth to list for under $2000 U.S. They were introduced at a time when there was fierce competition in the market for less-expensive polyphonic synths, competing against models from Sequential Circuits, Yamaha, Moog and Korg, among others. The Junos were Roland's first models to make use of a digitally controlled oscillator (DCO).
Juno Voice Architecture[]
All three Juno models have the same basic voice architecture, with one DCO generating three waveforms: a pulse wave, a sawtooth wave and a suboscillator square wave, plus a white noise generator. The pulse and sawtooth waves are on/off, but the level of the suboscillator and noise can be varied. An OTA lowpass VCF, a high pass filter (not voltage controlled), and VCA complete the audio path. An LFO (producing only a triangle wave) and an ADSR envelope generator are available as control voltage sources; the envelope generator was always routed to the VCA, and could be routed to the VCF either inverted or non-inverted. The Junos also had, as a global effect, a built-in version of Roland's excellent analog chorus circuit, which added significantly to the synth's appeal. All had six voices, as indicated by the model numbers.
All Junos had a four-octave, C-to-C, non-velocity or aftertouch sensitive keyboard, and an early version of the Roland pitch stick. All three models were built using the same basic case design, with similar panel layout and graphics. The line of slider controls across the top half of the panel is a distinctive feature of the design.
Juno-6[]
Roland Juno-6, courtesy of Soundgas.com
The first of these, the Juno-6, was introduced in 1982. Aimed at a price point far below the high-end Jupiter-8, it was only a moderate success because it lacked patch memory. Additionally, it did not have MIDI, being that the initial specification was still being developed at the time. (A Roland DCB bus interface was made available as a factory option.) However, it did have a few features that did not carry over to the later models. The high pass filter was infinitely variable, and a third chorus modulation speed could be had by pressing the chorus I and II buttons simultaneously. A switch allowed either the envelope generator or the LFO to be routed to the DCO pulse width modulation.
The performance-control area to the left of the keyboard contained a one-axis pitch stick (it moved left and right only), with two sliders that allowed both the DCO pitch and the VCF cutoff frequency to be modulated by the stick, in various proportions. In place of a mod wheel, a large white button labeled LFO TRIG would, when pressed, route the LFO to the DCO pitch, pulse width modulation, or VCF cutff frequency, in proportions as selected by controls in the control sections for those components. (A switch in the LFO controls could override the button and apply LFO modulation all of the time.) An octave select switch and a master volume control completed the performance control section.
The Juno-6 was one of the first lower-priced synths to have a built-in arpeggiator. Switches on the panel allowed the arpeggiator to act over a one two, or three-octave range; select the pattern (up, down, or up/down alternating), and set the repeat rate. A "hold" button allowed an arpeggiation to be latched so that it would continue playing after the performer removed their hands from the keys. An external clock jack on the rear allowed the arpeggiator to be clocked externally; when a cord was plugged into the jack, it overrode the rate control on the panel.
Juno-60[]
Roland Juno-60, courtesy of Audio Fanzine
The Juno-60 was introduced a few months after the Juno-6, as a more-featured version (at a higher price); both were marketed alongside each other. The most noticeable improvement over the Juno-6 was the 56 patch memory locations. It also came with the Roland DCB control bus as a standard feature. (Later, a DCB-to-MIDI adapter extended MIDI to this synth.) The -60 retained the -6's arpeggiator, keyboard, and performance controls, and the basic voice circuitry was the same as the -6.
The main addition was the patch memory, which memorized all of the voice parameters (but not the arpeggiator parameters). A red border on the panel indicated which controls were remembered. The basic panel layout of the Juno-6 was retained, with the patch memory controls somewhat awkwardly crammed in on the right side. The memory also included a cassette interface for saving and reloading patches. 56 available patch memory locations were indicated on the panel, but other "hidden" ones were accessible by pressing (undocumented) combinations of patch selection buttons. The Juno-60 was one of the first synths to be equipped with a test mode, which the technician could use to calibrate the circuitry and diagnose various circuit faults.
The variable high pass filter of the Juno-6 was replaced by one having four discrete settings, numbered 0 through 3. 0 was a bypass position; 1-3 were in increasing order of cutoff frequency. Another improvement over the Juno-6 was the addition of a seventh VCA, placed after the voice mixer; the "level" control in the VCA section controlled the level of this final VCA. This allowed sound designers to equalize the output levels of different patches. The "hidden" third chorus rate of the Juno-6 was eliminated.
Juno-106[]
Roland Juno-106. Photo by the author.
In 1984, both of the earlier models were superseded by the Juno-106, which increased patch memory to 128 slots (a rather astounding total, in an era when memory was expensive). The other major addition was MIDI; although this was not the first Roland synth to come with MIDI from the factory, its MIDI implementation was far more extensive than almost any other synth on the market at that time. It included a facility for remote editing of patch parameters via sysex and transmission of movements of the programming controls via same. This made the 106 one of the first remotely programmable synths on the market. Note that there are a few aspects in which the MIDI interface does not conform to current standards; this is due to the incomplete nature of the standard at the time the 106 was designed. The user should also note that the 106 boots up in omni mode; selecting a MIDI channel number takes it out of omni mode.
To get the price and number of components down, Roland took the voice architecture of the 60 and miniaturized it for the 106. They bought unpackaged ICs (the bare chips) from the chip vendors and encapsulated them into two custom hybrid IC designs, one containing most of the DCO circuit, the other containing the VCF and VCA. Unfortunately, the latter (the infamous 80017A) had a design fault that caused the ICs to gradually fail over time, a situation that 106 owners today are still having to deal with. Additionally, the LFO and envelope generators, which had been in hardware on the previous Junos, became microprocessor-generated software functions. These measures did get the list price of the 106 down to less than half of the all-conquering Yamaha DX-7, which made the 106 one of the few analog synths to go head-to-head in the market against the DX-7 and become a hit; Roland sold over 40,000 units.
The 106 lost the arpeggiator of the previous models, but it gained another interesting feature: polyphonic portamento. To gain some control over this, two different voice allocation algorithms were provided, either of which could be selected via buttons on the panel. The "poly mode 2" setting allowed the performer to control voice assignment by carefully arpeggiating chords, making the voice assigned to each note, and hence the behavior of the portamento, predictable. A third mode, unison, was of limited value due the phase-synchronized characteristic of the DCOs (they are all timed by the same master oscillator), which produced an unpleasantly buzzy and non-moving sound.
The high-pass filter was revised from the Juno-60 design. Position 1 became the bypass position, with only 2 and 3 as actual high-pass settings. Position 0 became a bass boost setting. This small change has been the fulcrum of many arguments from Juno-60 vs. Juno-106 devotees over the intervening decades.
The same keyboard from the earlier Junos was retained, but the performance controls were rearranged. The separate modulation trigger button was replaced by adding a second axis to the pitch stick; pushing the stick away from the performer activated the modulation. (It was still only an on/off function, but the amount of modulation to be applied could be controlled with a slider.) The octave select switch was moved to the DCO control section; replaced by an on-off switch and rate knob for the portamento. On the panel, the patch selection, cassette interface and MIDI interface controls were moved to a row underneath the parameter sliders. Patch memory was divided into two "bank groups" each of which could be loaded or saved to cassette separately. (Cassette patch data dumps are not compatible between the 60 and the 106.) Each bank group contained 8 banks of 8 patches each. Plugging a foot switch into a rear panel jack allowed the performer to rotate through the 8 patches of the currently selected bank by pressing the switch once for each patch change. A MIDI channel select button allowed the user to use the bank and patch buttons to select a MIDI channel (which had to be re-selected at each power up).
The controls on the 106 were moved somewhat closer together than on the previous models, and the power switch was moved to the rear panel, leaving blank areas at each end of the panel. These blank areas were used as a place to put loudspeakers in the Juno-106S and HS-60.
Juno-106S and HS-60[]
Roland HS-60 personal keyboard. Courtesy of Audio Fanzine.
The Juno-106 served as the basis for two attempts by Roland to break in to the personal-keyboard market, by adding an audio amplifier and loudspeakers to the synth. The Juno-106S was nearly identical to the regular 106, with the addition of loudspeakers in the unused areas at each end of the panel. The HS-60 eliminated the colorful graphics from the panel, in place of a basic grey and white scheme, and a badge on the panel identified it as the "SynthPlus 60". Roland made a few other attempts in the '80s to enter the personal-keyboard market with reworked existing models, without much success, as the market came to be dominated by Yamaha and Casio.
Summary[]
This was the end of the Juno series proper, although the MKS-7 rackmount synth shared the Juno voice architecture. In 1985, Roland superseded the Juno-106 with the Alpha Juno series, which used a completely different voice architecture. The Juno-60 and 106 remain valued by performers and collectors (the 60 slightly more so by some), with the Juno-6 somewhat less highly regarded. Both the -60 and -106 have the useful feature of being able to changes patches instantaneously, a feature seldom found on later synths.
As discussed above, the Juno-6 and 60 were dropped in 1984, when the 106 was introduced. The 106 was withdrawn in 1987 or '88, after the introduction of the Alpha Juno models. The Junos were (with the exception of the personal-keyboard models) a sales success for Roland, with some sources stating that the total number of all three models produced was in excess of 100,000.