A data compression apparatus is disclosed for data compressing an audio signal. The data compression apparatus comprises an input terminal (1) for receiving the audio signal, a 1-bit A/D converter (4) for A/D converting the audio signal so as to obtain a bitstream signal, a lossless coder (10) for carrying out a lossless data compression step on the bitstream signal so as to obtain a data compressed bitstream signal, and an output terminal (14) for supplying the data compressed bitstream signal. Further, a recording apparatus and a transmitter apparatus comprising the data compression apparatus are disclosed. In addition, a data expansion apparatus for data expanding the data compressed bitstream signal supplied by the data compression apparatus is disclosed, as well as a reproducing apparatus and a receiver apparatus comprising the data expansion apparatus.