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

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

Regular price $419.00 Sale

June 29th, 2020 - Back in stock.  Units will be shipping again by the end of the week.  


Covid-19 Shipping Alert:  If you place an order, please be aware that if you use US Postal service to place in international order, then there will be a longer than usual shipping time.  All international US Mail shipments have been switched from air mail (fast) to sea freight (slow) because of lack of airplane availability.  Since there are few international flights, most packages will travel by sea, which on average, is taking 6-8 weeks for a parcel to arrive at its destination.  This delay can be avoided by using mail services with their own air fleet, such as UPS, DHL, and Fed Ex.  These are more expensive than US International Post, but they will be much faster.  We apologize for the inconvenience and long shipping times.  Please be aware of this when you buy.  


Latest firmware: 1.79  


 User's Manual V1.31 (First production run.  Users should update OS to latest OS)

User's Manual V1.35+ (Latest edition)


When purchasing, please select your adapter type, or select "no adapter" if you do not need one.  

Retroaktiv MPG-50 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.  Optional powder-coated rack ears are available for an additional $25.


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

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

A 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 basses, polyphonic comp, bells/metal, percussion, pads, synth brass, strings, drones, noise FX, kick drum, snare/tom, cymbal/hihat, clavichord/e piano, dance (Hoover type sounds)  or completely randomEach 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)  The amount of randomness can also be dialed in, making the random tone generator on the MPG50 a powerful creative tool.  

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

3 assignable controllers can be configured to control up to 5 Juno parameters each. (CTRL A, CTRL B, and Expression pedal)  Control range for each parameter can be set, and the controls can be inverted for each parameter.  Each ASSIGN has a factory default as well as a user preset, allowing for 6 ASSIGNs, alll of which can be recalled with a button press.  Incoming mod wheel and aftertouch MIDI messages can be routed to ASSIGN A and ASSIGN B, allowing for up to 5 parameters to be controlled with each.  

MIDI preferences can be saved with a button press, eliminating the need to reconfigure your settings on power up.  

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 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.  



The latest OS for MPG50 is 1.61  







 June 2020 - Prices have been raised on these because we have been forced to pay a 25% tariff on our pots, sliders, slider caps and knobs.  These are only available from one place in the world, and if we buy from there, an excessive 25% tariff is assessed.  We are forced to pass this cost on to our customers.  China doesn't pay for these tariffs, Retroaktiv does.  Tariffs are bad for US based businesses and force us to hire less, pay more to make our goods, and charge more to the consumer.