This is IMHO the ultimate analog machine. The possibilities are vast and by tweaking them good ole 'nobs and sliders while playing, it's easy to make nice things happen. My favourite is the "solo" mode which stacks all 16 oscillators on a single key depression, creating an incredibly thick and beefy sound.
On the sad side, there is no MIDI (this is an oldie, remember?), although you can use a DCB to MIDI interface (if you can find one).
Some JP-8's also seem to have the nasty habit to reset themselves in the middle of a playing session due to some weird internal electronic spike - rendering them pretty useless on stage.
If you're not deeply and incurably in love with old and classic synths, you would probably be a lot happier with the Roland Super Jupiter module (MKS-80) instead. You get all the power of the Jupiter plus MIDI and new features like velocity and pressure sensitivity. And hey, with the MPG-80 programmer you get all the knobs and sliders too!
This damn board has absolutely impressive analog sounds! Altough it has no modular capabilities or complex modulation routings, what it does, it does so darn well! It's even fatter than the Jupiter-6, I think doe to its oscillator structure. The JP-6 uses Curtis Electromusic chips for oscillators, and the JP-8 employs oscillator boards, with discrete components. It features one LFO with sine, saw, square and random waveforms, VCO-1 with triangle, saw, variable pulse or rectangular waveforms, and VCO-2 with sine, saw, variable pulse or pink noise waveforms. The VCO-2 is syncable to VCO-1.It features a mixer knob, to balance between VCO-1 and VCO-2. It has a non-voltage controlled high-pass filter, and a voltage controlled low-pass filter with selectable cutoff slope of -24dB/oct or -12db/oct; the resonance does not cranks to self-oscillation. the VCF can be modulated from the env-1 or env-2 and LFO. The VCA can be modulated by env-2 and LFO. It has two envelope generators, with key follow. Its envelopes uses analog ADSR chips, the IR3R01, which provides 1msec attack time, very suitable for punchy attack synth basses. The JP-8 features an arpeggiator, with four octave range, with up/down/up&down and random modes. It can be set in "whole" mode, with one single patch across the keyboard and 8-voice polyphony, "split", with a four-voice different patch in each side of the keyboard, and "dual", with two different patches layered together providing 4-voice polyphony. It has also a CV/gate output. Altough most pictures found on the net shows the JP-8 as a black keyboard, it has a metallic charcoal grey finishing, just like the JP-6. I love its rugged Jeep-like construction, with thick aluminum side panels.