Roland Alpha Juno 1 (1985)

 

The last of the Classical "Juno" series, an interesting hybrid analog & digital characteristics with Midi interface and memory.

KEYBOARD 49 keys (no velocity).
The main panel features an LCD display, 38 buttons and a data wheel "Alpha Dial"; on the left side a joystick that acts as both pitch bender and modulation function.

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

 

 

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:

 

WAVEFORMS here's some details about the JU1 waveforms:

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 1 on vacuum-tube oscilloscope

 

FILTER multimode VCF based on 6 X IR3R05 IC (also VCA):
- lowpass at -24dB/Oct : with resonance that does not reach auto-oscillation
- highpass: 4 scaled values.
The VCF also provides a 15-levels keytracking system.

famous roland IR3R05 IC

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

ENVELOPE 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.

 

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

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

 

MEMORY:
- 64 ROM presets
- 64 RAM slots.
Sounds must be saved to magnetic tape or Midi exclusives data dump
BATTERY REPLACEMENT : change lithium battery model CR-2032 soldered to the mainboard.

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.
- VST AU Alpha JUNO Editor (MAC-PC / $$) PIC
- Midiquest (MAC-PC / $$) PIC
- MKS-50 (Atari ST / now freeware ) PIC
- CTRLR (MAC-PC-LINUX / free) PIC
- Alpha BASE (PC / free) PIC
- Alpha Juno Control (MAC / free) PIC below.

RELATED MODELS :

	Alpha Juno 2 ALPHA JUNO1 VS ALPHA JUNO2: Ju2 is bigger with 5 octave keyboard velocity and aftertouch sensitive keys
	MKS-50 rack unit with some enhancements like Detuning, Portamento and a double RAM memory.
	HS-80 consumer version of alpha Juno2 with different outfit.
	HS-10 - an alpha juno1 with different case.
	PG-300 programmer compatible with all the JUNO series.

 

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

	name	price	demo
	PHUTURA SMC Joono VST	free VST emulation
	REDOMINATOR	commercial VST plugin

 

AUDIO DEMO

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

VIDEO CLIP SELECTION demo1 Techno Demo Track Hoover

 

 

Alpha juno with mimi the synthcat

MANUAL

SERVICE MANUAL

FACTORY PATCH

original brochure

original brochure