Owner`s manual

13
There is a single SPDIF single-ended digital output on an RCA connector. A final technical
highlight of the CDP-1.5 is the custom remote handset. It features an exceptionally wide transmission
angle to the IR receiver on the CDP-1.5, and is engineered to last an extremely long time.
The CDP-1.5 features an HDCD decoder that, in addition to allowing full HDCD decoding,
functions as a state of the art 8X oversampling filter if the input data is not encoded in HDCD format.
The CDP-1.5 employs a high performance 24-bit digital-to-analog converter, which serves to decode
both left and right channel information. The digital information is oversampled by the HDCD decoder to
a rate that is 8 times higher than the original sampling frequency. Oversampling the digital data to such
a high rate allows the analog filter following the DAC to have far fewer poles than would be otherwise
required. This allows a simpler analog filter to follow the DAC which reduces the errors that are
associated with “brick wall” analog filters, and also minimizes the number of components in the signal
path. With non-HDCD encoded data, the decoder exhibits performance to common digital filter IC’s.
The stop band attenuation is greater than -120dB, and the internal calculations are carried out with 27-bit
accuracy. If the data is encoded in HDCD encoded format, the filter will detect it and decode it,
extracting all of the additional information available with an HDCD recording. The HDCD indicator on
the front panel will dome on if the HDCD encoded data is detected. The indicator will be off for a
normally encoded CD. The analog gain is increased by 6dB automatically when an HDCD disc is
detected, as suggested by Pacific Microsonics, Inc. The HDCD filter also performs de-emphasis
filtering for discs encoded with pre-emphasis.
The output of the Burr Brown 24-bit 1704 DAC’s is followed by a 3-pole, linear phase, low pass
filter to remove any artifacts beyond the audio frequency range from the analog audio signal. The last
stage of the filter is a passive 6dB attenuator to provide the proper HDCD levels. The output stage uses
discrete components biased in class A.
The output is followed by relays to protect outside equipment from power-on transients as well as to
protect the CDP-1.5 from other equipment when the CDP-1.5 is not powered.