There are two sockets, 6.35mm and 3.5mm, wired in parallel. They're mechanically exclusive: plugging into the 6.35mm disconnects the 3.5mm. You can plug in one of these 3 things: * MIDI - TRS MIDI, type A or type B * Expression pedal - a passive potentiometer pedal * Footswitch

Sends HID or MIDI commands via USB

WiFi desktop alarm clock

Monitors the salt level in a water softener

Switch off the mains after some amount of time