Astell&Kern AK240 Mastering Quality Sound Portable Dual DAC High-Fidelity Audio System, Cirrus Logic CS4398 x2, Stainless Steel DSD (Direct Stream Digital) is a digital audio file format originally developed for SACDs (Super Audio CD). Regular digital audio file formats such as PCM (Pulse Code Modulation) is separated into 65,000(16bit) to 16,700,000(24bit) of information on the Y axis, and 44,100(44.1kHz) to 192,000(192kHz) across the X axis for digital signals. DSD files have 1bit (0s or 1s) for Y axis and is separated into 2,800,000(2.8MHz) to 5,600,000(5.6MHz) of information for X axis. Compared to regular audio CDs with 16bit/44.1kHz PCM format, SACD's recording frequency goes up to 100kHz and the dynamic range goes beyond 120dB while maintaining sound clarity during the transmission. Astell&Kern has created the AK120 Titan with a storage capacity of 128GB, but in order to support Native DSD, MQS, and massive audio files, we had to come up with the ultimate portable music player with 256GB of storage. Display: 3.31" WVGA (480 x 800) AMOLED Touchscreen  Output Level: Unbalance 2.1Vrms / Balance 2.3Vrms (Condition No Load) Supported Audio Formats: WAV, FLAC, WMA, MP3, OGG, APE(Normal, High, Fast), AAC, ALAC, AIFF, DFF, DSF  Sample rate: FLAC, WAV, ALAC, AIFF: 8kHz to 192kHz (8/16/24bits per Sample) / DSD Native: DSD64 (1bit 2.8MHz), Stereo / DSD128 (1bit 5.6MHz), Stereo