The Doepfer A-139-2 Headphone Amplifier Eurorack Module is a 2 channel headphone amplifier. One or two stereo headphones with 6.3mm (1/4") stereo jack plugs can be connected to the A-139-2. The minimum headphone impedance is 8 Ohm. The levels of the audio signals connected to the audio inputs can be adjusted separately for each input. The Master Level knob controls the overall loudness for both channels. The maximum power output is 2 x 2W

The main features of the Doepfer A-110-4 Thru-Zero Quadrature VCO Eurorack Module include:

• 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)
• Silver Chassis