DSD128

DSD128 is a Direct Stream Digital (DSD) audio format that encodes audio as a 1-bit delta-sigma modulated stream at 5.6448 MHz, i.e., 128 times the CD sampling rate. This positions it above DSD64, which uses 2.8224 MHz, in terms of raw temporal resolution, at the cost of higher data rates and more demanding processing. In DSD, the audio signal is not represented in conventional multi-bit PCM; the data are typically stored inside DSF or DFF file containers, and can be transported via DoP (DSD over PCM) for compatibility with PCM-based playback chains.

A stereo or multichannel DSD128 stream consists of interleaved 1-bit samples across channels. Playback requires hardware and software that can handle either native DSD128 or DoP-assisted DSD data. While SACD content and some high-resolution downloads can carry DSD128, widespread consumer support lags behind DSD64, though support is improving in premium DACs and modern software players.

Advantages of DSD128 include high temporal resolution and simple analog reconstruction in theory; disadvantages include very high data rates, larger storage requirements, and greater demands on DACs and jitter-sensitive electronics. In practice, the perceptual benefits depend on the playback chain and listening conditions.

DSD128 is one of several rate variants in the DSD family, alongside DSD64 and DSD256, and is primarily encountered in specialized audiophile contexts rather than mainstream consumer music services.