VOICE main core H8/570 manages 24 oscillators polyphony; the DAC is a Burr- Brown PCM61P (18 bits). A single patch is composed by 4 PCM layers by the JD WG wave generator that can be interconnected into algorithms modes (check out table below).
Each layer features some parameters:
- level mix
- pitch coarse + fine
- pitch random amount
- pitch key follow mode from -100 to +200% range
- FXM frequency cross modulation (8 levels + depth)
- oscillator period sync mode
- wave delay start time
- velocity range trigger threshold low and high
- key zone low and high.
ALGORITHMS the tones can be combined in 6 signal paths (list) or structures.
These are pre-fixed audio patches that connect the 2 pairs of tones into variable setups mixed with 3 audio elements: amplifier, filter and ringmodulation (4 models).
TECH: same algorithms can be found on Roland sampler DJ70.
WAVETABLE internal 6MB ROM contains 195 PCM waveforms sampled at 44 kHz and organized in 5 categories:
- basic waveforms inspired by analog synthesizers like "fatsquare" "synsaw" or "fatsaw"
- mathematical transients and overtones inspired from Roland D-50 L.A. synthesis
- one shot percussion acoustic samples
- samples from acoustic instruments
- loops and noises.
The JD-990 added new waveforms to ensure also compatibility with Roland JV-80.
FULL PCM LIST HERE
EXPANSION the JD-990 can be expanded using 3 kinds of cards:
- 8 X SO-JD are JD800 Roland set
(data + PCM)
- 21 X SR-JV with different purposes and instrument styles
Roland PN JV80 series 8 x SO-PCM1.
One of the most sought-after model is the VINTAGE expansion Srjv-04 a must-have adds 256 sounds made exclusively for the 990 + 256 others designed for JV series.
|SRJV EXPANSION CARDS:
||SO JD DATA + PCM CARD set
||SUPER SOUND SET
||KEYBOARDS OF THE 60's & 70's
||BASS AND DRUM
||SPECIAL FX Collection
||EXPERIENCE 1 promotional board
||EXPERIENCE 2 promotional board
JD9D SERIES, esclusively made for JD990
PERFORMANCE the system handles 7 patches (+1 drum) with these mix settings:
- coarse + fine tune
- analog out assignment
- effect amount
- panning position
- level mix
- voice priority
- monophonic / solo with legato mode and portamento
- aftertouch can be assigned to TVF / TVA / WG pitch
- breath can be assigned to volume / amplitude / modulation aftertouch.
FILTER a multimode (lowpass / highpass / bandpass) digital resonant filter is assigned for each PCM layer. Using algorithms 2/3/4 it is possible to chain filters eg: 2 lowpass mode filters at 2 poles can be put in series to obtain a doubling effect at 4 poles slope.
ENVELOPE 3 EGs for each PCM layer:
- EG pitch: 3 segments level + 3 times
- EG filter (TVF) : 4 segments + 4 times
- EG amplitude (TVA) 4 segments + 4 times
All EGs offers a keyfollow mode and 7 curves, in addtion the panning position can be set either specific stereo values, to random or assigned to keyfollow mode too.
LFO up to 2 delayed modulators with variable depth and note retrig mode with fade IN time.
The modulators are
interchangeable and they do provide 8 shapes with variable offset : triangle, saw, square, sample & hold, random standard, random chaos, trapezoidal and sinewave.
There are 4 destinations:
- freely assignable to matrix destination
- LFO to amplitude
- LFO tofilter cutoff
- LFO to WG pitch.
MATRIX each PCM layer offers 8 virtual patching cords for modulation control.
The general setup defines 2 sources and matrix control sets the destinations with variable depth amount (positive and negative values). Check the sum-up table:
||SOURCES B :
LFO1-2 pitch modulation depth
LFO1-2 filter modulation depth
LFO1-2 amplitude modulation depth
EFFECT FX DSP is split into 2 groups: A (mono) + B (stereophonic). Effects from A-B can be chained in different combination order and relative parameters controlled by Midi controllers such as modulation, aftertouch, expression, breath, pitchbender and foot control.
EQ shelving model 3 bands: low - med - high
|- 7 distortions models with drive amount
- phaser with depth / rate
- dynamic enhancer
- a 6 bands spectrum enhancer
- stereo delay up to 600 Ms can be synched to Midi clock
- chorus with rate, depth and feedback
- 5 reverbs including Room, Hall, Gate, Reverse and Flying mode.
MIDI basic CC# including:modulation, panning stereo volume gain and hold
TIP: JD-990 can be edited by a JD-800 but unit IDs must be matched in system options, also JD-990 is compatible with JD-800 but not the contrary.
64 RAM patches
- 128 ROM patches
16 RAM performances
- 32 ROM performances
- 1 RAM rhythm setup
- 1 ROM rhythm setup
RAM doubled if Roland m-256 E (or D) is present
Battery replacement: a simple CR2032 3V in a holder, easy to change!
EDITOR there are some computer softwares:
- Soundquest (PC/MAC, $$$)
- Sounddiver (out of business)
- JD990 layout (IOS IPAD, free)
- CNTRL (open source, free) INFO
Roland JD800 VS JD990 Comparison chart
|JD-800 is more or less the previous keyboard version with a lot of realtime control but . Here's the differences: (roland jd800 vs jd990)
- JD990 lacks hold pedal and expression pedals.
- Jd990 lacks real-time controls
- JD800 features 4mb Vs 6mb Jd990
- JD800 is a limited performance structure
- JD800 features less analog outs
- JD800 lacks panning position
- JD800 lacks matrix modulation
- JD800 lacks polyphonic portamento
- JD800 lacks Sr-Jv slot expansion
- JD800 misses 3LFO shapes: sin, trapezoid, chaos
- JD800 lacks waveform sync
- JD800 lacks frequency cross modulation FXM
- JD800 lacks ringmodulator
- JD800 lacks algorithmic structures
JD800 cannot read more than 1mb PCM
- JD800 delay is limited to 600ms (vs 3000)
- JD800 delay cannot be synched to Midi
VST PLUGIN / SAMPLED VERSION NO JD-990VST has ever been released, however there are some free and commercial samples set:
||free sample pack (JD800)
|| Sampleism JD-850
(Note: I am not sure this product has been officially approved by Roland. Roland has strict policy on their samples.)