n this paper, an overview of DSD signal processing is given. It is shown that 1-bit DSD signals can be dithered properly. Here, properly means that the resulting dithered DSD stream does not contain audible artifacts in a band from 0-100 kHz. It is also shown that signal processing can be done best in a high rate, multi-bit domain. The minimal frequency span needed to comply with the human auditory system appears to be roughly 0-350 kHz (»8.1 kHz). Following the signal processing, final conversion to DSD is made. We make a plea for SACD as a consumer format; it is the format which, while maintaining all necessary psycho-acoustical characteristics such as high bandwidth, filtering with wide transition bands etc., uses the least bits from the disk; hence offering the longest playing time.

Introduction
In the past few years, there has been an evolving trend in the audio world to move from the standard CD-format (i.e., 16 bit resolution, and a sampling frequency of 44.1 kHz) to other formats, which offer a higher resolution. A nice description of this otherwise rather vague definition is given by the AES high-resolution audio technical committee: every carrier offering more than 2 channels, each 44.1 or 48 kHz and resolution corresponding to 16 bit, is coined as high-resolution. Hence, high resolution embraces both multi-channel recordings and audio formats which allow for a higher definition of the audio data per sé, such as SACD, which stores 1-bit words at a sampling frequency of 64 times 44.1 kHz, and DVD-A, which covers a wide variety of sampling rates (44.1/48 to 176/192 kHz) and wordlengths (16-24 bit). Often, the SACD data format is called bitstream or Direct Stream Digital (DSD) to contrast it with the Pulse Code modulation (PCM) used in the