The Topping D30 Pro Desktop DAC is a converter for many digital signal sources. USB (Universal Serial Bus) coaxial & optical inputs can all be sent through the quad DAC circuitry in this device. What makes this a step up from the lower-priced products in Toppings range is the additional outputs. The D30 Pro has full balanced XLR outputs & a single-ended RCA output. The D30 Pro supports up to 384k Hz PCM as well as DSD at 256 bits. With this range you can listen at whichever quality you may own music without any loss of fidelity. The D30 Pro is a very simple addition to your setup. Simply plug the device into your mac or pc with no additional drivers required. Additional software is required for playing the highest quality files. The D30 Pro has a preamplifier function built into the unit allowing you to connect to power amplifiers or speakers with little to no noise. This device can be expanded upon using the Topping A30 Pro headphone amp. This will provide the additional benefit of high-quality headphone listening.