The PX-350 has 1/4' audio outputs and USB-to-Device output so you can easily connect the PX-850 to recording and sound reinforcement equipment. You can choose (separate from what the actual PX-850 cabinet will do) whether you ant the lid on the Grand Piano open, closed, half or removed. A very special other feature is the Lid Simulation. The PX-850 keys feature Damper Resonance, Hammer response and Sympathetic Resonance. The PX-850 has 18 Instrument tones (5 are Piano), and 256 note polyphony. A combination of a keyboard action and a powerful sound engine provide a level of detail, nuance and expression for a superior grand piano experience in the lightweight and stylish design that Privia is known for. The PX-850 represents a significant step in the continuing evolution of the Privia digital piano line. Description Casio PX850BK Digital Piano 88 Weighted Keys