ROLAND ALPHA JUNO 2 - A Hidden Gem of Analog-Digital Synthesis

The Roland Alpha Juno 2 is a six-voice polyphonic hybrid synthesizer, introduced in 1985 as an improved version of the Alpha Juno 1. It brought several key enhancements, including a 61-key expanded keyboard, aftertouch, and the ability to externally store sound programs on a RAM cartridge, the Roland Memory Cartridge M-16C.

Thanks to the combination of digitally controlled oscillators (DCO) and an analog filter, the Alpha Juno 2 became a favorite among musicians looking for warm analog sound with digital stability.

Sound Architecture and Flexibility

The Alpha Juno 2 features six-voice polyphony, allowing for rich chord structures and complex sound layering.

Key Components of the Sound Architecture:

•  DCO (Digitally Controlled Oscillator) – Stable oscillators with PWM (Pulse Width Modulation)
   capability.
•  24dB low-pass filter with resonance – The filter is designed as two 2-pole state-variable filters
   cascaded, resulting in a 4-pole low-pass filter. Unfortunately, the filter resonance did not allow
   self-oscillation.
•  LFO with various waveforms – Enables modulation of oscillator frequency, filter cutoff, and
   amplifier settings.
•  Envelope generators – Dynamic control of amplitude and filter for expressive sound variations.
•  Built-in chorus – Adds depth and width to the sound, perfect for lush pad sounds.

Memory and Sound Storage Options

The Alpha Juno 2 includes 64 factory presets and 64 user memory slots, allowing for custom sound design.

Additionally, user sounds can be stored externally on a RAM cartridge, the Roland Memory Cartridge M-16C, providing extra storage space for sound programs.

Sound Programming and Control

One of the most distinctive features of the Alpha Juno 2 is its Alpha Dial, a rotary control replacing the traditional slider-based interface.

For musicians who prefer classic slider-based control, Roland offers the optional programmer PG-300, allowing direct access to all parameters without menu diving.

Roland PG-300 – The Alpha Juno 2 Programmer

The Roland PG-300 is an external programmer, specifically designed for Roland Alpha Juno 1, Alpha Juno 2, and MKS-50. This hardware controller provides direct access to all synthesizer parameters, significantly simplifying sound programming compared to the standard menu-driven control of the Alpha Juno 2.

With 30 dedicated sliders, the PG-300 delivers intuitive and fast editing, making it an ideal tool for musicians who prefer hands-on control rather than navigating digital menus.

Key Features of the Roland PG-300:

•  30 sliders for direct parameter control – Allows instant editing of oscillators, filters,
   envelopes, and modulation.
•  MIDI In/Out/Thru ports – Enables connection to other MIDI devices.
•  Compatible with Alpha Juno 1, Alpha Juno 2, and MKS-50 – Functions as a full-fledged sound
   editor for these synthesizers.
•  Real-time control – Allows live sound adjustments without stopping playback.
•  Ideal for live performance – Its quick parameter access makes it perfect for on-stage use.

Roland Alpha Juno 2 – Hidden Features and Inspirations from Iconic Synthesizers

The Roland Alpha Juno 2 is more than just another analog-digital synthesizer. Many of its features were inspired by classic synthesizers, while some functions remain less known, despite their significant impact on sound creation.

Influence of Moog Source and Synclavier

One of the most unique aspects of the Alpha Juno 2 is its Alpha Dial – a rotary controller replacing traditional sliders for sound editing.

The Alpha Dial enables quick parameter editing without the need to navigate complex menus. While some musicians prefer traditional slider control, the Alpha Dial provides smoother sound editing, especially useful for fine-tuning filters and envelopes.

Yamaha DX7-style Envelope Chart

On the right side of the Alpha Juno 2 control panel, there is a graph displaying envelope phases, reminiscent of the Yamaha DX7. This visual aid helps musicians better understand the complex DADSR envelopes – Delay, Attack, Decay, Sustain, Release.

Extremely Slow LFO for Unique Sound Modulation

The Alpha Juno 2 includes an LFO that allows for extremely slow frequencies, ideal for gradual sound evolution. Unlike standard Juno models, its LFO can be set to very low frequencies, unlocking possibilities such as:

•  Slowly evolving ambient textures
•  Subtle filter sweeps
•  Smooth automatic detuning of digital oscillators to emulate the drift of analog oscillators, giving
   the sound a sense of "liveliness" or unpredictability.

This feature makes the Alpha Juno 2 an excellent instrument for various electronic music styles.

Hidden “Chord Memory” Function

One of the least known but most exciting features of the Alpha Juno 2 is its Chord Memory function, which allows musicians to store an entire chord and play it with a single key.

This function was especially popular in techno and rave music, where it was used to create fast chord sequences, impossible to play manually on a regular keyboard. Combining Hoover sound with Chord Memory resulted in the iconic sound of the early '90s.

HS-80 – The Home Version of Alpha Juno 2

Few people know that Roland also released the HS-80, a home version of the Alpha Juno 2, aimed at casual users rather than professional musicians.

While the sound engine of the HS-80 was identical to the Alpha Juno 2, the design was different – the HS-80 featured preloaded demo songs, simplified controls, and was marketed as a home music instrument.

Today, the HS-80 is a rarity, but it still offers the same sound capabilities as the Alpha Juno 2, making it an interesting collectible.

Connectivity and MIDI Options

The Alpha Juno 2 features MIDI In/Out 5-pin DIN connectors, allowing seamless integration with external sequencers, DAWs, and other synthesizers.

Thanks to velocity and aftertouch, the Alpha Juno 2 easily integrates into modern studio setups, functioning as either a main keyboard or a sound module.

Artists Who Used the Alpha Juno 2

The Alpha Juno 2 became a favorite among many musicians, especially in electronic music. Some well-known users include:

•  Massive Attack – Used Alpha Juno 2 for atmospheric pad sounds.
•  The Prodigy – Used the Alpha Juno 2 for its iconic Hoover sound.
•  Fatboy Slim – Utilized Alpha Juno 2 for synthetic bass lines.
•  Vince Clarke (Depeche Mode, Erasure) – Used Alpha Juno 2 for sequenced synthetic textures.
•  Joey Beltram – Used the Alpha Juno 2 in techno productions.

Conclusion

The Roland Alpha Juno 2 is a unique hybrid synthesizer that blends the digital stability of oscillators with an analog filter, creating a distinctively warm sound.

Thanks to its six-voice polyphony, flexible memory, MIDI connectivity, and external programming options, the Alpha Juno 2 has become a beloved instrument among electronic musicians, valued for its powerful basses, expressive leads, and lush pad sounds.