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MPG-50 mkII Programmer for Roland Alpha Juno 1 & 2 and MKS-50

MPG-50 mkII Programmer for Roland Alpha Juno 1 & 2 and MKS-50

Regular price $640.00 Sale

Out of stock.  We have an incoming production of these arriving this spring.   We will continue to allow orders to be placed, and they will ship when the incoming batch of MPG-50 mkII arrives.   We expect to have more MPG-50 in early May.

 Latest firmware versions:

 MPG-50 mkI & mkII 3.06-3.07 Firmware Update (March 10th, 2022)  This zip file contains the latest vesrion for mkI units and mkII units.  MkI users should select the detent/non-detent based on which type of encoder their unit has.  

Espen Kraft Preset Bank 1 (In Retroaktiv format. )

Espen Kraft Preset Bank 2  (In Retroaktiv format)

User's Manual V1.35+ (Latest edition for mk1 perating systems below 3.x) 

 User's Manual V3.0 for MK1 and MK2 Units running OS 3.x

Setting Up Retroaktiv Controllers In Your Rig


Retroaktiv MPG-50 mkII  is a fully featured MIDI programmer for the popular Roland Alpha Juno 1 and 2, and the MKS-50 rackmount synthesizer.  The MPG-50 is a compact 370mm (14.5") x 149mm (6") x 40mm (1.5").   It features 37 sliders and knobs which control all of the features included on the original PG-300 plus more.   The unit is housed in a high-quality rugged powder-coated metal enclosure.  


MPG-50 mk2 is more than just a controller.  Here's what else it can do:

  • Translates CC to Juno sysex, and transmits CC and SYSEX in any combination.  Full CC automation of all parameters.
  • Multi-unit mode turns 2 Alpha Juno/MKS into a DUAL layered stack (Like a 2-tone synths such as MKS70 or MKS80) that can be stored on the MPG-50 as a SETUP, allowing for lush, layered sounds at the push of a button.
  • Ability to store patches directly on controller.  Stock MPG-50 mk2 units ship with 32k of memory on-board.  This can be expanded to 160k by choosing the 128k memory expander option.  Stock mk2 units can store 4 banks of patches + 20 ASSIGN + 20 SETUP + 20 CC Maps.  Expanded mk2 units can store 12 banks of 64 patches,  2 banks of 64 ASSIGN, 2 banks of 64 SETUP, and 1 bank of 64 CC Maps.  
  • Daisy chain 2 AJ/MKS-50 to create a 12-voice "Super Juno".  Store "Super Juno" sounds as a single SETUP.  
  • 3rd MIDI IN/OUT port allows users to configure MIDI connections to suit their needs.  This port can be a MIDI IN or an OUT.  
  • Controls 2 Alpha Juno/MKS-50 from one unit
  • Intelligent patch generator creates pads, drums, basses, synths, strings, brass, and more with the touch of a button.
  • Operating system is always being updated with new features.  OS updates are done using a simple MIDI file!
  • Access to all patch menu parameters (MKS50) and ability to select programs.
  • Create user CC maps to use MPG-50 as a generic controller.
  • Assignable matrix allows users to control multiple parameters with one slider for expressive effects.  Also allows expression pedal, mod wheel, aftertouch, and breath control of any Alpha Juno parameters.
  • Scratch patch generator and "manual mode"
  • Crossfade between 2 Alpha/Junos
  • MIDI data filtering
  • High quality metal case.  Sliders have dust covers.  Durable rubber feet.
  • Chord Mode
  • Midi data filter.  Individual toggles to filter note, mod wheel, prog change, pitch bend, aftertouch.

The MPG-50 mkII features 2 controller channels, MAIN and AUX.  Users can switch between the MAIN and AUX channels to control multiple Alpha Juno/MKS50 synthesizers separately, or simultaneously, or a USER CC map can be assigned to a layer.  This feature allows two Junos to be seamlessly combined to create a 2 DCO "super Juno".   When both synths are selected, the MASTER VOLUME fader on the MPG becomes a cross-fade control that fades between two Junos, making controlling 2 Junos or MKS50s feel like an integrated "super Juno".  

MPG-50 can convert CC messages into sysex messages.  The programmer uses sysex and CC to communicate with the synth. In CC mode, moving a slider will send a CC message (for recording the CC with a DAW) and a sysex message (to the synth). In CC  translate mode, playing back recorded CCs or sending CCs from a controller will result in that CC being translated to sysex and sent to the DW.   Incoming MIDI data can also be re-mapped to a different channel  (useful if using the MPG-50 to simultaneously translate incoming CCs from a DAW while also recording new slider movements from the DW8P).

When the unit is set to translate CC---->SYSEX, there are several choices of modes:

CC+SYSEX MODE - When a parameter on the DW8P is changed, a sysex message and the corresponding CC (for your DAW to record) is transmitted.  

CC ONLY MODE - When a parameter on the DW8P is changed, only the CC is transmitted (For your DAW to record, then send back into the DW8P and be translated into a sysex message for the synth)

SYSEX ONLY MODE - Incoming CCs will be translated, but none will be transmitted.  Use this mode if you have already recorded your CC track, or you are using CCs from a controller keyboard. 

To prevent a feedback loop, MIDI can be translated on one channel, then "bumped" to another channel and transmitted to the synth.  (Synth must be in omni mode for this to work)  This is useful if people are recording and playing at the same time. 

MPG-50 mkII will allow incoming breath, mod wheel, and aftertouch messages to be routed to any 5 Juno parameters each.  

20 USER CC maps are available allowing for the MPG-50 mkII to control other synthesizers.  Each user map features 33 sliders and knobs, where each slider can transmit any CC on any MIDI channel independently.  

Freeze function allows users to freeze the controller, change any parameters they want, then send all changes in one burst.  

patch generator function allows for users to create new "scratch" programs (basic programs that serve as a starting point for creating sounds), a random patch generator, a manual function (transmits the position of all 39 front panel parameters),  as well as a user configurable random generator that will randomize only parameters selected by the user.  The patchgen menu features the following:

Random Tone Generator - Features multiple random categories, such as BASS, PAD, PLUCK/STRUCK, BELLS/METAL, STRINGS, PIANO, ORGAN, SYNC, BRASS, and more Each section of the synth can be set to be "masked" (Not randomized) :  DCO wave/level, DCO pitch mod, VCF level/rez, filter mod, VCA mod, chorus, LFO, Env times (T1, T2, T3, T4, Follow) and Env levels.  (L1, L2, L3)  

HOLD feature will sustain all notes played on the Juno until HOLD is disabled.

MIDI Modulation Matrix - Use CTRL A, CTRL B, an expression pedal, any CC message, aftertouch, key scaling, or velocity to control any combination of parameters on the synth.

In the main menu, users can select MONO or POLY mode, adjust bend range,  and save and recall AUX/Pedal assignment settings.  For MKS-50 synths, there is a patch menu giving access to : Detune, transpose, upper range, lower range, tone number, and modulation sensitivity.

The MPG-50 operating system is continually updated with new features.  The MPG-50 OS can be flashed using a MIDI file.  No special equipment is needed to update.  Simply use the MPG-50's MIDI bootloader to load a new operating system onto the programmer!

All menu information is displayed on a compact OLED screen, allowing for deep editing and the display of parameter values being transmitted.  

MPG-50 mkII offers all of the functionality of the original PG-300, plus a suite of modern performance and MIDI features that make this the most full featured Alpha Juno programmer on the market.  



Retroaktiv is based in the United States.   Note that purchases made from outside of the US may be subject to your country's VAT, customs, tariffs, or sales taxes.  We do not have anything to do with these fees.  They are assessed and charged by customs in your country.  When checking out, all shipping charges are for shipping transit only, and do not include any customs fees.