Direct Stream Digital

DSD (Direct Stream Digital ) method is a high-resolution audio signal stored based on the principle of the delta-sigma modulation.

Is applied to DSD technology mainly in the Super Audio CD ( SACD). The improvement in sound quality based on the 2.8224 MHz high sampling rate of a delta -sigma modulator in comparison to linear 16 -bit converters with a sampling rate of 44.1 kHz, the Red Book audio CD.

The thus-obtained high-resolution data stream is recorded directly and are compared to the PCM technology not quantized level values ​​again, but extremely high-resolution delta-sigma values, ie change information on the progress of the audio level. Thanks to the extreme oversampling stored in the pulse stream audio data are more precise than conventional audio data stored. In reproduction, a similar effect will take place, since the interpolation and anti-alias filters are unnecessary, which are heretofore used in the conventional CD to remove frequencies above 20 kHz. The DSD format, the frequency response is extended to 100 kHz, with a dynamic range of about 120 dB in the audible frequency range. Due to the low dynamic principle of a sigma -delta analog -to-digital converter with only one bit quantizer, however, the result is a huge conversion noise, however, which occurs through the effect of the noise shapings in a very high frequency and thus inaudible range.