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Roland U-20

RS PCM Keyboard (1989)

Roland u20

"Revamped U-110 module with same engine: keyboard version with larger wavetable and better DACs. Rackmount version is U-220"


KEYBOARD 61 velocity keys with aftertouch.  The main panel features a 24 X 2 backlit display, 42 buttons, 3 sliders and a pitchbender & modulation joystick. 

PERFORMANCE  synth manages up to 6 timbres (+ 1 drum part) and individual settings:  split zones, stereo panning position, volume gain,  voice priority,  analog out routing and  aftertouch, which can be assigned to LFO, pitch and volume. 

Terminal connectors : 
- headphones out
- main signal out 
- aux out (only dry) 
- Midi interface 
- Pedal expression input (EV-5 or EV-10) 
- Pedal switch input for sound hold function (DP-2 or DP-6) 
- 2 slots for PCM and data cards

roland u20


SOUND system based on a Intel P8098 CPU which handles 30 voices polyphonic subtractive synthesis RS PCM Resynthesized Pulse Code Modulation. RS concept resynthesizes and rebuilds new harmonics using a custom sample interpolation, but it lacks a filter structure in fact RS can be mistaken with older L.A synthesis implemented in Roland D-50 model. 
Sound hierarchy is a bit confusing: the lowest level is a tone which is composed by either 1 or 2 samples (2 samples tone reduces the whole polyphony) out of 128 tones available (drum is apart) with no possible edit. The upper level is the timbre composed by a single tone that has some editable parameters: volume, detune and vibrato LFO.  Finally 6 timbres make a patch for performance. 

WAVETABLE 4 Pure rompler synth: 3MB ROM (6X 512 kb ROM) is organized in 2 sound groups:
- acoustic samples eg: piano, bell, guitar, string, organ, brass [...] 
- precalculated basic waveforms eg: pulse, sawtooth and generated harmonics.

CARD EXPANSION The ROM can be expanded using special PCM cards, also compatible with: Here's the list of available models:
SN-U110-01: Pipe Organs & Harpsichords
SN-U110-02 :Latin and FX Percussion
SN-U110-04: Electric Grand and Clavi
SN-U110-05: Orchestral Strings
SN-U110-06: Orchestral Winds
SN-U110-07: Electric Guitar
SN-U110-08: Synthesizer
SN-U110-09: Guitar and Keyboards
SN-U110-10: Rock Drums INFO
SN-U110-11: Sound Effects
SN-U110-12: Sax & Trombone
SN-U110-13: Super Strings
SN-U110-14: Super Ac Guitar
SN-U110-15: Super Brass
>Also third part cards from Musitronics Akkordeon (ID: 25 / Analog Synthesizer / Voices (ID: 22) / Eldek (ID: 21)
roland u20

U20 Parameters

ENVELOPE a single 4-stages amplitude EG.

LFO  modulates only the amplitude with variable depth, delay time and 9 shapes: triangle, sinewave, square, saw up, saw down, trill (x2) and random (x2).  Special AUTOBEND function is a basic modulation for a pitch-warp effect, so it should be considered as another simpler LFO.

EFFECTS there are 2 main FX sections with limited edit parameters:
- reverb: 9 presets including hall, delay, room and gate 
- chorus: 5 presets including chorus, flanger and delay. 

ARPEGGIATOR & CHORD PLAY a basic arpeggiator system with no sync Midi clock: up / down / updown / random.  A chord can be assigned to each key, allowing you to play chords with a single finger. Since a different chord can be assigned to each key C, C# - B, you can perform using diatonic chords or harmonies in thirds. Up to 8 sets of chords can be stored in the U-20 (diatonic, Sus 4, octave, power) 

MEMORY 64 patches + 64 performances  + 4 rhythm sets. RAM is doubled if RAM card model Roland m-256 is fitted.

Press PART and RHYTHM simultaneously to enter ROM play mode, hold MARK and JUMP, press ENTER to enter Test mode, While holding JUMP, press NUMBER .ENTER,VALUE [^] to confirm. Hold MARK and JUMP, press EXIT

Roland u20

U20 Maintenance and issues

REPAIR  There are 2 common reported time issues worth to check out:  tact switch may need cleanig or direct replacement (better solution) and dead keys. Here's a vid tutorial to repair such problems:  

Roland U20 Specifications

Company: Roland
Model: U-20
Class: digital Synthesizer
Synthesis: PCM samples with synthetic timbres
Keyboard: 61 keys, velocity, monophonic aftertouch
Country: Japan
Dates: 1989
Actual Price: 150€
Synthesis: PCM rompler
Wavetable: 3 mb Rom
Polyphony: 30 voices
Multitimbric: 6 parts
LFO: 1 modulator
Midi: in out thru
Effects - Reverb, Delay, Chorus; arpeggiator
Memory: 64 slots
IC: P8098 CPU
Weight: 10 Kg
Dimensions: 98,5 (w) x 31 (h) x 9 (d) cm

video demo

Do you use this machine ? do you like it?  Let us know in the comment field just below 


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