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Roland Alpha Juno 2



Roland Alpha Juno 2

infoCountry: JAPAN
Weight: 7,5 Kg
Dimensions: n/a
audio demo trend price : 300€
manual demo demo video comments


Roland Alpha Juno 2 (1985)


An update from previous budget synthesizer JUNO-1 with a larger and dynamic 61 keys keyboard.


alpha juno waveforms

info KEYBOARD 61 velocity keys with aftertouch.
The main panel features a LCD display, 39 buttons and a jog wheel. On the left side a joystick that acts as both pitch bender and modulation functions.

Rear panel terminal connectors:
- Midi interface
- tape interface
- main out
- headphones out
- expression pedal assignable to volume / aftertouch / velocity
- assignable pedal: patch up / portamento on-off / chord memory on-off
- hold pedalswitch input.

edit VOICE main CPU Intel 8032AH manages 6 voices polyphony.
Each voice has an assigned DCO oscillator based on custom Roland IC MB87123PG and each DCO is composed 2 summable waveforms + 1 sub oscillator + 1 noise generator:


Waveform Harmonic variations: Level width: range:
pulse 3 - yes (3rd shape) 4' 8' 16' 32'
saw 5 - yes (3rd shape) 4' 8' 16' 32'
suboscillator 5 yes - 1 / 2 oct below
white noise 0 yes - -


alpha juno 2 on oscilloscope


alpha juno2 schematics


adsr PERFORMANCE some Ju-2 special playmode functions:
- octave transpose keyboard
- portamento glide
- chord mode learn (it outputs Midi)
- bender range 1 octave setting
- key transpose
- 15 aftertouch levels assignable to VCF / DCO / VCA.
MIDI some basic CC# are managed including: modulation, foot control, portamento time
and hold



filter FILTER multimode VCF based on 6 IC X IR3R05 (also VCA).
- lowpass at -24dB/Oct /resonance (it does not auto-oscillate)
- highpass: only 4 preset values.
VCF system provides keytracking system scaled to 15 values

filter VCF


adsr LFO
a single delayed modulator and 2 destinations with individual depth values:
- DCO pitch
- VCF filter.

LFO rate

a single 4-stages + 3 time levels with polarity inversion EG assignable to:
- DCO pitch
- VCF filter cutoff
- VCA amplitude with special gate mode.
In addition the VCA provides a 15-levels keytracking system.

eg alpha juno

section features an analog stereo chorus based on 2 X MN3101 + 2X MN3009 IC like Juno-60 or Jx-3p with adjustable rate

BBD chorus

memory MEMORY
- 64 ROM presets
- 64 RAM slots + 64 others if optional cartridge m64c is fitted.
Sounds can be saved to magnetic tape or Midi exclusives data dump.
BATTERY REPLACMENT: change lithium battery model CR-2032 soldered to the mainboard.

battery replacement


memory REPAIR
the Juno series a pretty reliable on time, with no particular technical issues.
The Juno2 most common problem is the dead keys, which involves cleaning the contacts, please do follow this very useful video:

repair alpha juno keyboard

edit EDIT
main panel lacks many real-time commands, but there are many computer software or it is possible to use the dedicated optional programmer model Pg-300.
- Alpha Juno Control (MAC / free) PIC
- VST AU Alpha JUNO Editor (MAC-PC / $$) PIC
- Soundquest (MAC-PC / $$) PIC
- MKS-50 (Atari ST / freeware now) PIC
- Alphabase (old PC freeware) PIC
- CTRLR (MAC-PC-LINUX / free) pic below

alpha juno editor


Alpha Juno 1 Alpha Juno 1 smaller version with 49 keys (no velocity) and no cartridge port.
MKS-50 MKS-50 rack unit with some enhancements like Detuning, Portamento and a double internal RAM memory.
HS-10 HS-10 - an alpha juno1 with different case.
HS-80 HS-80 it's alpha Juno2 consumer version of with different outfit and powered internal speakers VIDEO


PG-300 programmer compatible with all the JUNO series.


effet VST PLUGIN / SAMPLED VERSION there are some free and commercial samples set:

  name price link demo
EFM Oddse PHUTURA free VST emulation
effet phutura vst
audio oddy SMC Joono VST free VST emulation effet SMC Joono VST
odsay REDOMINATOR commercial VST plugin effet redominator


demo SANXION (track overdub) with TR-606
demo Performance 1 + drum samples
demo Performance 2 + drum samples
demo Performance 3 + drum samples
demo Performance 4 + drum samples
demo Performance 5 + drum samples
demo Performance 6 + drum samples
demo Organ: b3 even more poor
demo Harpsichord: like a 8 bits
demo Piano: analog poor
demo Clavinet: naaaa
demo Bass: funky
demo Bass: mooga
demo Bass: razor
demo Bass: jumpy
demo Bass: soft quiet
demo Bass: attack
demo Drums: analog kit
demo Drums: timpani
demo FX: scary ohhhhohhhh LOL
demo Ambient: chill
demo Ambient: space
demo Ambient: system
demo Pad: murky
demo Pad: chorus
demo Pad: time bandit
demo String: LFO movement
demo String: very simple
demo Synth: WOOObled
demo Synth: what's a hoover?
demo Synth: Drill
demo Synth: droning
demo Synth: melodie d'amour
demo Synth: rate by rate
demo Synth: resonance up
demo Synth: square world
demo Synth: slippery when dry
demo XP: waveforms all pulses
demo XP: suboscillators waves
demo XP: sawtooth width
demo XP: pulse width
demo XP: white noise and filter
demo XP: lowpass and resonance
demo XP: highpass mode filter
demo XP: LFO all shapes
demo XP: Chorus BBD

effet Soundcloud alpha juno2

demo1 3 tracks 3 tracks


Alpha Juno-2 Demo Roland Alpha Juno 2 Roland Alpha Juno-2 Some Presets
demo1 demo2 Some Presets


roland aplha juno 2







Roland Ju2 service manual
Roland Alpha Juno 2 SERVICE MANUAL


original scan



original scan






Roland Alpha Juno 2 FOR SALE




alpha juno motherboard alpha juno motherboard roland epom


- velocity
- weird waveforms


- edit
- EG / LFO
- no arpeggiato


REVIEW "Good JU1 update, especially for new keyboard features. Just pay attention to contact stripes board that mail fail in time. "


alpha juno 2 logo






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all snapshots, sounds, texts copyright Polynominal.com / Eric Pochesci

roland alpha juno2 3.5 out of 5 based on 29 ratings. price €300