Features Sound engine evolution Greater sonic dimension More multidrive Wider range and dirtier than ever before Room for two - More headroom means Duo mode sounds even better Upgraded Keybed Lightweight with swift action, velocity, and aftertouch High-power amp headphone Cue up your next sound in the loudest of venues. Limited edition - 2000 units produced worldwide SUB 37 Design All the controls and features found on the Sub 37 Tribute Edition: Perform in Mono or Duo modes 37-note velocity-sensitive keyboard with aftertouch 2 modulation busses with assignable source and destinations DAHDSR (Delay, Attack, Hold, Decay, Sustain, Release) looping envelopes with sync 256 presets - 16 banks of 16 patches Syncable arpeggiator and step sequencer Classic Moog Ladder Filter with resonance, Multidrive, and selectable filter slopes