The perfect headphone module by Doepfer.
two-channel headphone amplifier
two audio inputs with level controls
Input 1 is normalled to Input 2
common loudness/master level control
headphone output (stereo 1/4″ jack socket)
max. output power ~ 2 W per channel (@ 8 Ohm load)
DC coupled inputs and outputs (i.e. also useful for other applications like small loudspeakers, lamps, LEDs, magnets, motors – provided that the power is sufficient)