The MKS-50 is a rack-mount version of the Alpha Juno. It has the same synth engine and architecture, with some added features like 16 programmable chord memories, the ability to store velocity, volume, panning, de-tune, portamento and other similar parameters within each patch you create. The optional and highly recommended PG-300 will give you traditional slider type control of all editable tone parameters which include DCO (digitally controlled oscillators) LFO, bend, ENV, pulse, waveforms, noise, PW/PWM, high pass filter, VCF (filter) with freq/env/res/LFO/kybd, VCA envelope, chorus, and more.
Its sound is not quite as warm as the previous Juno's but it's still a nice addition to any techno synth rig. Other features include better MIDI implementation than previous Roland synths, a nice LCD display, an LFO capable of a very slow rate for some cool sweeping effects, and a great bass sound (especially nice for acid basslines) and noise effects! It is used by Überzone, Astral Projection, Fluke, Future Sound of London, Pet Shop Boys, and Vince Clarke.
The PG-300 is a tone programmer for the Roland Alpha Juno 1, 2 and MKS-50 synthesizers. It offers complete control over all editable parameters in an easy to use, well designed controller. It uses a standard Midi cable (not provided). It features 30 sliders for real-time total control. No more scrolling through menus and sub-menus to adjust sounds.