https://youtu.be/JiZSY06xNC0   The Palmer Monicon® L is a precise, analogue volume control that connects between a computer or audio interface and active monitor speakers. The switch is completely passive and distortion-free, the LED displays and built-in headphone amplifier are powered via the included power supply. Symmetric combo sockets serve as stereo input. The Monicon® L’s AUX input features RCA sockets and a 3.5 mm stereo jack. The compact console offers outputs for two monitor pairs and a mono summed output via XLR sockets. The stereo or AUX input can be selected alternately, the two outputs individually and together. In addition to its large volume controller, the Monicon® L is also equipped with mono, mute and PFL switches, a 6.35 mm headphone output, and separate AUX and headphone controllers for convenient operation.   Specifications Product type Other Studio and Recording Equipment Channels 2 Inputs 2 Input connectors 3.5 mm TRS , RCA , XLR Input type balanced/unbalanced (depending on TS/TRS connection) Max. input level 20 dBu Input impedance (balanced) 10k Ohm(s) , (unbalanced) 5k Ohm(s) Outputs 3 Output connectors XLR Output type balanced/unbalanced (depending on TS/TRS connection) Max. output level 20 dBu Output impedance 600 Ohm(s) Frequency response 10 - 40000 Hz Total Harmonic Distortion (THD) 0.001 % Max. attenuation (Attenuator + Mute) 112 , (Attenuator) 85 Controls attenuation , input selector , mono , mute , output selector , PFL source Cabinet material sheet steel , wood Cabinet surface Powder coated Width 218 mm Height 77 mm Depth 100 mm Weight 1,14 kg   More info, https://www.palmer-germany.com/en/products/studio-monitors-and-monitor-controllers/5194/monicon-l