16 [TRIGGER]
Input for connecting the pads using the included cable.
17 [LINE OUT]
Output socket to connect an amplifier or powered monitor.
18 [LINE IN]
Input socket for connecting audio devices like CD and MP3 players, etc.
19 [VOLUME]
Rotary control for adjusting the headphones output volume.
20 [PHONE]
Headphones output.
21 [USB]
USB port for connecting a PC with USB-MIDI interface.
Operating elements
MPS-500 USB
23