The Jupiter-8, or JP-8, is an eight-voice polyphonic analog subtractive synthesizer introduced by Roland Corporation in early 1981. The Jupiter-8 was Roland's flagship synthesizer for the first half of the 1980s. Approximately 3300 units have been produced. Although it lacked the soon-to-be standard of MIDI control, later production series of the Jupiter-8 did include Roland's proprietary DCB interface. The instrument had many advanced features for its time, including the ability to split the keyboard into two zones, with separate patches active on each zone. Two years after the release of the Jupiter-8, Roland released the more affordable Jupiter-6 synthesizer with built-in MIDI control but an otherwise slightly reduced set of features. In 2011, three decades after the release of the original Jupiter series, Roland released the fully digital Jupiter-80 and Jupiter-50 synthesizers as successors to the 1980s originals. They were in turn succeeded by the Jupiter-X and Jupiter-Xm in 2019. A Jupiter-8 plug-out was included already installed on the Roland System-8 synthesizer, in 2017. Features and architecture The Jupiter-8 is an 8-voice polyphonic analog synthesizer. Each voice features two discrete 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. An assignable bender can be used to control pitch or filter frequency. 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 divide down if more keys are pressed. No other polyphonic synthesizer at the time had this feature. 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 operations. The VCF was based on the custom Roland IR3109 IC (also used in the filter circuits of the Jupiter-6, later Jupiter-4 and Promars units, MKS-80 rev 4, Juno-6/Juno-60/Juno-106, SH-101, MC-202, JX-3P and packaged