Channels The MK1 has three independent input ports:Clean – undistorted, clearCrunch – distortedLead – stressing the middle, highly distorted Plugs from left to right Main connectionMain fuseFuse for the output stageLink for the footswitchSend and return socket for an external device (FX Loop)Two parallel plugs for loudspeakersLoudspeaker impedance 8/16 ohm