The D-Z555 is undoubtedly the most complex of all the Discman models. A technology showpiece, it was crammed with all Sony’s digital audio know-how and what resulted was a superlative product the like of which will never be seen again. Text copyright © Walkman Central. Unauthorised reproduction prohibited.
The D-Z555 was the first Discman to employ 8 times oversampling. This method of CD playback reduced the amount of digital “noise” that could enter the analogue stages and resulted in a purer sound than was obtainable by conventional means. Sony’s own CXD2551 digital filter was used, feeding two Burr Brown PCM66P digital to analogue converter (DAC) chips. This arrangement would have been a high specification for a domestic machine but in applying it to a Discman Sony demonstrated how serious they were about portable audio. On top of this, they also included one of the first “Digital Signal Processors” (DSP) to be seen in a consumer product. The functions of the DSP were shown on an extra LCD on top of the machine and included a programmable 5 band graphic equaliser, digital surround sound and various other enhancement options. The volume control was also implemented digitally and this had its own display section too. On normal playback the DSP displays became a peak programme meter and both the DSP display on the top and the track display on the front were illuminated in orange when an external power source was used. Text copyright © Walkman Central. Unauthorised reproduction prohibited.
The D-Z555 was also unique at the time in offering an optical digital output. This could be used to connect the player to an external DAC, a digital amplifier, a Digital Audio Tape (DAT) recorder or later a MiniDisc recorder like the MZ-1. Text copyright © Walkman Central. Unauthorised reproduction prohibited.
The D-Z555 was produced at a time when the personal compact disc player was still considered a luxury item. The situation would change in the next few years and soon such machines would be reduced to the status of a more common commodity. This precluded the production of further extravagant technology statements like the D-Z555, it is most unlikely that their like will be seen again. Text copyright © Walkman Central. Unauthorised reproduction prohibited.