via this auction

The JX-10 is a 12-voice analog monster sometimes referred to as 2 JX-8P's in one body. This thing can output up to 24 analog oscillators at once and do basic FM, keyboard splitting, has built-in chorus and can be controlled externally to act as 2 different synths. This is seriously the most affordable package you'll find for that many analog voices (12 total).
The keybed is semi-weighted with aftertouch and makes a fantastic master keyboard. It's very playable and the 76 keys span 6 octaves to allow for very versatile playing and can also be split to play two patches (or "tones" in Roland-speak) at once. So you can very easily play bass with your left-hand, and pads or lead with your right.
Some cool things enabled by the upgrade:
• MIDI CC/Sysex input
• Map 2 of the onboard sliders to any parameter
• Arpeggiator
• Custom display options
More info about the Vecoven upgrade's added features [pdf link]"