Roland MKS-50 For Sale. Synthesizer module equivalent of the Roland Alpha Juno-1 and Alpha Juno-2 keyboards. This unit has been professionally refurbished, unlike most. The internal battery was replaced and what we believe to be the original factory patches were reloaded. Cold solder joints were corrected. The volume pot was cleaned. All synthesizer parameters were tested on all voices and are working as they should. This investment of time and money should hopefully result in an instrument that will outlast others of its type and is justifiably reflected in its price.