Our first DAC-1 units came with USB that supported 16bit/44Hz files. We later upgraded the standard USB in the DAC-1 to support 24bit/96Hz files. If you plug in your DAC and the output device window that pops up in the lower right corner of your screen says USB Audio Codec detected the unit supports 16/44. If the window first says USB device detected, then W4S 24/96 USB Interface your unit will support the higher bit and sample rate. The units with 16/44 can be upgraded. If you are interested in upgrading please contact us at firstname.lastname@example.org and the cost and details can be discussed.