||It has been suggested that List of Roland Jupiter-8 notable users be merged into this article. (Discuss) Proposed since May 2016.|
|Oscillator||2 VCOs per voice|
|Synthesis type||analog subtractive|
12 or 24 dB/octave resonant lowpass,
|Attenuator||1 ADSR envelope for VCA|
|Storage memory||64 patches|
|External control||DCB (on later models)|
The Jupiter-8 was Roland's flagship synthesizer for the first half of the 1980s. Although it lacked the soon-to-be standard of MIDI control, later model Jupiter-8s did include Roland's proprietary DCB interface, and all of them sported advanced features and the ability to split the keyboard into two zones, with a separate patch active on each zone.
Features and architecture
The Jupiter-8 is an 8-voice polyphonic analog synthesizer. Each voice features two VCOs with cross-modulation and sync, pulse-width modulation, a non-resonant high-pass filter, a resonant Low-pass filter with 2-pole (12 dB/octave) and 4-pole (24 dB/octave) settings, an LFO with variable waveforms and routings, and two envelope generators (one invertible).
Features include adjustable polyphonic portamento and a Hold function for infinite sustain of notes and arpeggios. A versatile arpeggiator can be synchronized with external equipment by using the proprietary Roland DCB interface, clock input via CV jacks on the rear panel, or one of the aftermarket MIDI kits from Encore or Kenton. An assignable bender can be used to control pitch or filter frequency.
From the factory, the JP-8 could store 64 patches. Patches could be stored to, or loaded from, a standard analog tape/cassette. The Encore JP8MK MIDI kit doubles the patch memory to 128 and enables the JP-8 to store and recall patches over a MIDI connection, using a computer with sysex utility software.
The Jupiter-8 includes balanced stereo XLR outputs as well as unbalanced 1/4" outputs. In addition to monophonic and polyphonic modes, the Jupiter-8 includes a unique, polyphonic unison mode, in which all 16 oscillators can be stacked onto one note, but would then be divided down shouuld more than one key is pressed. This was an unusual feature as no other polyphonic synthesizer at the time did this.
A Zilog Z80 CPU was used for managing storage of patches; scanning the keyboard and front-panel controls for changes; displaying the current patch number and other information on the display; and taking care of the auto-tune function, among other things. The VCOs were discrete. The VCF was based on the custom Roland IR3109 IC (also used in the filter circuits of the Jupiter-6, later Jupiter-4 units, MKS-80 rev 4, Juno-6/Juno-60, SH-101, MC-202, JX-3P and packaged in the 80017a chip used in the Juno-106 and MKS-30 among others). The VCA was the BA662, used also in Juno-6/60/106, JX-3P and TB-303. The envelopes were generated in hardware by the Roland IR3R01 chip (also in the Juno 6/60), and are much faster (1ms attack) than the software-generated envelopes used in the later Jupiter-6, Juno-106 and MKS-80 "Super Jupiter".
There are claims that early models had unstable tuning, mainly due to their panel slider encoding resolution and main control voltage generation. However, this may be limited to the first 500 JP-8s that were manufactured. Beginning with serial number 171700, the 12-bit DAC was upgraded to a 14-bit DAC. This increased the resolution of the controls but had little to no effect on the overall sound quality. The soldered-in battery typically lasts ten years or more, ranking these boards among the lowest-maintenance of their generation.
In the present day
The wide range of sounds that the Jupiter-8 can produce, the efficient front panel layout (each synthesizer sound parameter adjustment had its own dedicated controller), and its sturdy construction, make the Jupiter-8 a venerable and desirable instrument even 30 years after it was first produced. Units in good condition still fetch more at auction than most new synthesizers, suggesting that the Jupiter-8 will continue to be heard for years to come. While the characteristic sound of the Jupiter-8 can be heard on many songs from the early 1980s onward, it is still being recorded to this day. For example, Alicia Keys can be seen playing one in the video for the number one hit "No One."
Jupiter changes and successors
Throughout the production of the JP-8 there were several changes. Starting at serial #171700 the D/A converter on the Interface board was changed from 12-bit to 14-bit. This change was made mainly to improve tuning stability. The problem with the 12-bit digital-to-analog converter on the original JP-8 is that it could cause the autotune to be inaccurate in some instances. Some say to avoid these early JP-8's while others say they haven't experienced tuning problems. Starting at serial #242750 the LEDs of the display were changed to brighter ones. Starting at serial #282880 the JP-8 came standard with a DCB port. These newer JP-8's may be referred to as JP-8A's. DCB, or Digital Control Bus, was Roland's pre-MIDI interface that allowed the JP-8 to talk to other DCB enabled hardware, such as the Roland MC-4 and MC-8 microcomposers. Previous JP-8's had the option of having the OC-8 retrofit installed to give it DCB capability.
The Jupiter-6 was released 2 years after the JP-8 and was an attempt at more affordable version of Roland's flagship. It features a similar voice architecture and appearance. It stored fewer patches, and had six voices. In order to make it cheaper to manufacture, a move towards integrated circuits (Curtis) was made, to replace discrete circuits used in JP-8's oscillators and amplifiers. The JP-6 is built using CEM3340 chip for its oscillators, and CEM3360 for its voltage controlled amplifiers. These changes imparted a change in sonic character, meaning that the JP-6 is not simply a less-expensive version of the JP-8, but an instrument with its own distinct sound. Additionally, the Jupiter-6 features a true multimode resonant filter, built-in MIDI, unison detune function and the ability to activate multiple waveforms on a single oscillator.
The Roland MKS-80 "Super Jupiter" is a MIDI-controlled, rack-mountable sound module with a similar voice architecture to the Jupiter-8. However, its first released incarnation in 1984 (revision 3 and 4) used hardware identical to its predecessor, the Jupiter-6 (which had a combination of Curtis VCO and VCA chips combined with Roland's own proprietary filters). In 1985, Roland released another revision of the MKS-80, known as "Rev 5," which used different VCO, VCA, and filter circuits. As a result, the MKS-80 Rev 5 can sound quite different from its predecessors. The Rev 5 filter was also used in the JX-8P, JX-10 and MKS-70 synthesizers.
At the 2007 NAMM show, French music software manufacturer Arturia announced, and subsequently released a software Jupiter-8 called Jupiter-8V. A 2007 review in Sound on Sound stated, "8V sounds much like Jupiter 8, but does a zillion things that the original could not." The Jupiter-8V is available in VST, AU, and RTAS plugin formats.
The Roland VariOS provides a mildly successful digital approximation of the Jupiter-8 using its "Varios-8" software.
In 2011, Roland released the JUPITER-80 and JUPITER-50, which inherit much of the visual style of the Jupiter-8 and include Roland's SuperNATURAL, an extensive synthesis engine that includes virtual analog synthesis akin to a digital recreation of earlier Roland analog synths, as well as PCM-based recreations of purely digital synths by the company and acoustic modelling of real instruments.
On October 1, 2015, Roland released the Boutique line of compact synthesizers, which includes the JP-08 unit which has the same parameters and sound design as the Roland Jupiter-8. It uses Roland's ACB technology (Analog Circuit Behavior), which emulates the behavior of each single component of the original Jupiter-8 circuit.  
- "JP8MANPD.PDF" (PDF). Retrieved 2014-07-03.
- "The Roland Jupiter 8 Analog Synthesizer". Synthtopia. 2009.
A Z80 CPU was used for managing storage of patches, scanning the keyboard, display, and buttons, port handling, and taking care of the auto-tune function among other things.
- "• View topic - registry?". Roland-jupiter.org. Retrieved 2014-07-03.
- Gordon Reid. "Arturia Jupiter 8V". Soundonsound.com. Retrieved 2014-07-03.