Doepfer LMK4+ Midi Master Keyboard (new version with USB) - Manual (Page 22)

LMK4+ User's Guide Page 22
Appendix B: Pin Assignment of the Jack Sockets
Appendix C: Conversion table Bank/Numbers to Decimal System
1 2
Power Supply
1 = +7...12V DC
2 = GND
"high"
end
"low"
end
2...10k linear
Foot Controller
(EXT.CTRL. 1/2)
Foot Switches
(SWITCHES)
Switch 2
Switch 1