1、This DAC converter converts coaxial or for Toslink digital audio signals to analog left/right audio and can be connected to an external device, such as an amplifier, through a standard for RCA type jack, with the option of a 5mm/0.1in headphone jack for output, high fidelity headphones, ideal for home or professional audio switching. 2、The bi‑directional switch is designed to be more powerful than the DAC converter, supporting not only digital‑to‑analog but also digital‑to‑analog (for Toslink to Coaxial and for Toslink). Note that this converter supports digital‑to‑analog but not analog‑to‑digital. 3、There is hi‑fi amplifier chip, left/right and 5mm/0.1in output can drive 16 ~ 150OHm impedance headphone/sound. Support volume control, volume control knob, used to adjust the volume of the headphone port and for RCA port only, not for coaxial or for Toslink. 4、Using the volume knob, you can adjust the volume for RCA L/R + 5mm/0.1in jack audio output for easy use. 5、Easy to install, easy to operate. USB power cord, more environmentally , stable and convenient.