\rHi Pavel:
This is a totally passive device like most speaker selectors that do not have internal volume controls. The volume levels are controlled by the input Receiver, Integrated Amplifier or Source through an independent amplifier. We recommend adding impedance matching Volume Controls if you are planning to connect multiple speakers and play more than two pair at a time. It does have a power supply but just to power the LED's and IR remote sensor.
TL/4760\r