High-end consumer audio manufacturer Parasound
has released a CD player driven by a Mini-ITX computer, powered by Linux to make CDs "sound significantly better than anyone has imagined possible" according to the manufacturer. The Halo CD 1
utilizes a PC-grade CD-ROM drive that reads the track multiple times before it is converted to audio, nearly guaranteeing no error in playback.
The company has written an extensive white paper
on the subject -- in describing how the device works, it says that "the CD 1 reads a CD multiple times before committing data to an enormous memory buffer stored in RAM. Every data sector is initially read twice and the two reads are compared. When the two reads match it is because no bit errors were detected and that is accumulated in the buffer memory. When the two reads do not match, it is because an error has been detected. That sector is then read repeatedly until good data is obtained. If the maximum repeat read threshold is reached and the 30 seconds buffer is about to run out, the system switches to its pre-interpolation analysis mode. Data reading is then moved forward by only one sample at a time until the bad fragment is isolated."
The device has one coaxial BNC S/PDIF output connector, a set of RCA connectors, and a TOSLINK optical output. The manufacturer recommends the coaxial BNC S/PDIF output, with the TOSLINK as a secondary, as the RCA jack "might cause some signal reflections in the digital cable and more jitter than a BNC connection."
Frequency response from the unit is reported as 20-20,000Hz, with THD distortion of less than 0.06 percent at 1kHz. The signal-to-noise ratio is advertised as greater than 108dB, with a crosstalk of greater than 77dB at 20kHz.
The player is available in silver or black. Retail price of the device is $4,500.