The pad grid
The grid shows 16 pads with pad 1 in the bottom-left corner, the layout MPC-style controllers use. It starts at note 36, the kick drum in the General MIDI drum map, which is where many controllers put their first pad. If yours starts elsewhere, hit the bottom-left pad, read its note in the log and type it into Pad 1 note.
Every pad shows how often it fired and its lowest and highest velocity. Hit each pad softly and then firmly: a pad that needs a hard hit before it fires, or never gets past a medium velocity, has a worn sensor or a sensitivity setting that’s too low. Most controllers let you change the pad velocity curve, and some have a fixed full-velocity mode that sends 127 on every hit.
Double triggers
A pad that fires twice for one hit is caught by the Chatter check: the same note again within 30 ms. The pad gets an orange outline and the log marks the second note. On a controller it usually means a worn pad or a sensitivity set too high; on a new one it can also be a firmware issue worth reporting to the maker.
Knobs, faders and encoders
Turn every knob and slide every fader from one end to the other. Each control appears in the list below the checks with its name from the MIDI Control Change table, its current value and a strip showing every value it has reached. A healthy absolute control covers 0 to 127 in small steps. A step of 20 or more in one message is reported as a jump: the classic sign of a scratchy potentiometer, which often cleans up with contact cleaner. Buttons that send Control Change show as switches (0 and 127).
Pad aftertouch
Pads with pressure send aftertouch while you hold them. Watch Aftertouch: polyphonic aftertouch names the pad’s note, channel aftertouch sends one value for all pads.