Per bit (Precise Reproduction of Original Bits) reproduces the music signal recorded in 16-bit format from the CD in 20-bit resolution, as is partly used in studio technology today. For this purpose, short sections of the music signal are cached. These are then compared with similar signals in 20-bit resolution and the amplitude values of the 16-bit signals are corrected in accordance with the 20-bit values. The 20-bit signal sections are stored in a special Yamaha YAC 514 memory module."