The USB input facility allows DSD native playback which converts 5.6MHz DSD files directly into analog signals without needing first to convert it to PCM. It supports both the ASIO2.1 and DoP (DSD over PCM) conversion methods. Using the AI-301DA in conjunction with the TEAC HR Audio Player high-resolution playback computer software application, anyone can easily explore the world of high-rez digital audio, including 5.6MHz DSD or 32bit/192 kHz PCM files, without having to grapple with complex settings etc. When receiving digital audio signals from a computer via USB cable, the unit can operate in asynchronous mode, controlling the timing of the input signal using the UD-301's internal clock (which is identical to the one used in the UD-501). With asynchronous transmission over USB, signal compromising jitter is effectively eliminated, allowing digital audio signals to be transmitted in a pure, unadulterated state. When handling digital signals of 96kHz and less, users have the option to upconvert to double or quadruple the original signal sampling frequency. Even when playing back a 44.1kHz sound source (equivalent to CD sound quality) a smoother analog audio signal can be obtained in order to convert to a higher resolution digital signal. Naturally, this up-conversion facility can be switched in or out, according to the user's preference.