Glensound HA1M 2 Input Stereo Headphone AmplifierThe Signature HA1M is a broadcast specification 2 channel headphone amplifier, designed to operate in a mono or a stereo mode. The HA1M has 2 x XLR inputs that can be used as either a stereo input, or as 2 x mono inputs. There is a selector switch to change between mono and stereo modes. In stereo mode, the left input goes to the left ear, and the right input goes to the right ear. Each input has its own level pot for adjusting the volume level in the