840C Upsampling compact disc player
INTRODUCTION
Thank you for purchasing this Azur 840C Upsampling Compact Disc Player. This unit is part of our new '8' series range, taking Cambridge Audio to new levels of audio excellence. The 8 series range has been developed as part of our commitment to the
The 840C incorporates a raft of new technologies and features. Key to its abilities is the ATFTM (Adaptive Time Filtering) upsampling process - developed in conjunction with Anagram Technologies of Switzerland. This system intelligently interpolates 16 bit/44.1kHz CD (or other) data to 24bit/384kHz through the use of a 32 bit Analog Devices Black Fin DSP (Digital Signal Processor) for the very best sound quality. The ATF system applies sophisticated polynomial curve fitting interpolation and incorporates a time domain model which allows data buffering and re- clocking almost completely eradicating digital jitter.
Because the audio data rate is so high aliasing artefacts are moved way above audible frequencies allowing us to use a low order 2 pole linear- phase Bessel filter on the output for constant group delay and minimal phase shift.
Two very high quality Analog Devices AD1955 24 bit DACs (Digital to Analog Converters) are used in dual differential mode. As each channel has its own DAC to process information, completely separate and symmetrical analog filter circuitry can be implemented. These allow both left and right channel circuitry to operate identically, ensuring the 840C delivers fantastic
This fully balanced configuration largely rejects the already very low noise and distortion products present in the DACs and filters and provides an unprecedented level of performance.
A true balanced (XLR) output is fitted as well as a summed conventional unbalanced phono/RCA output. Automatic DC servo circuits null all DC offsets allowing no capacitors in the signal path at all.
Two digital inputs are fitted allowing other digital sources to be brought into the 840C and upsampled, the 840C then working as a very high quality DAC.
A digital output is also fitted which can even output upsampled data at various rates and word widths, independent from the main audio output, which is always set at 24/384 for best sound quality.
In addition to these audiophile features Control Bus Input/Output, IR Emitter Input and RS232 control are provided to make it easy to integrate this unit into Custom Installation systems if desired.
A completely new
Your CD player can only be as good as the system it is connected to. Please do not compromise on your amplifier, speakers or cabling. Naturally we particularly recommend amplification from the Cambridge Audio Azur range, and in particular the 840A Integrated Amplifier which has been designed to the same exacting standards as this CD player. Your dealer can also supply excellent quality Cambridge Audio interconnects to ensure your system realises its full potential.
Thanks for taking the time to read this manual; we do recommend you keep it for future reference.
Matthew Bramble, Technical Director
Azur upsampling compact disc player 3