Copland CDA 825 CD Player

Copland CDA825 CD Player

As a result of our quest to refine the musical capabilities of the CD-medium and our constant efforts to understand and target the underlying technological requirements, we believe that the introduction of the CDA825 offers significant improvements of sound reproduction from CD-media.

Obviously, the CD-medium is a digital representation of an initially analog event, and the design of the CDA825 is therefore determined by an ambition to reconstruct the complex and delicate harmonic structure of the original analog waveform. This objective adheres to all details of the design, as well as their integration into the whole. Starting with the power supply, the following paragraphs offer some insight into the various design considerations.
The routing and grounding scheme of the CDA825 power supply provides effective isolation between the digital and analog parts of the CD-player. Furthermore, the power supply has been designed to ensure constant low output impedance towards the power consuming electric circuits. The numerous individual power supplies in CDA825 are designed to operate with a constant power, thereby eliminating reverse modulation towards the transformers and the AC supply grid.

The servo/error correction circuit is a prime source of ensuring error-free extraction of the data from the disc. These circuits are designed by a few select semiconductor manufacturers. Extensive testing was performed in order to select the best chip-set available and then to provide optimum operation conditions for these devices.

Inherently to the red-book CD standard is an 8 -14 modulation, interleaving and Reed- Solomon error correction. Due to cost considerations, not all available decoder chip-sets include a full implementation of these powerful error- correcting capabilities. The Philips chip-set used in the CDA825 however does provide full implementation of all error-correcting schemes of red-book CD and therefore guarantees that the extracted data from the CD-Pro2LF mechanism are recreated correctly.
The CDA825 uses the Wolfson WM8741 24bit, 192 KHz DAC. Two of these devices are used - one for each channel. Each DAC consist of two Digital to Analog converters each providing an in-phase signal and an opposite phase signal. Combining two in-phase and two opposite-phase signals per channel, the statistical properties of the signals are taken to advantage; the signal power of the phases correlate and add-up in constructive addition, whereas the noise power of the phases are de-correlated, improving the signal to noise ratio of the resulting analog waveform.