The generated text mentions "DAC," which stands for Digital to Digital Converter. It connects via USB and converts to optical digital or coaxial digital. It supports high-resolution audio. Connecting it to your DAC via optical digital allows you to create an audio environment completely free from USB noise. The FX-AUDIO FX-D03J is a DAC that supports optical digital and coaxial connections. - Brand: FX-AUDIO - Model: FX-D03J - Connection Terminals: Optical digital, coaxial - Input Terminal: USB input Thank you for viewing.