How DVD Players Work
DVD players read and decode various compressed audio signals within the DSP of the unit. Movies contain Dolby Digital or DTS surround data, and high density Digital Audio Discs (DAD) contain 2 channel audio only. Two types of audio processing are provided in most DVD players. First, a digital output is generated. Using menu settings the output can be undecoded Dolby Digital, DTS audio, or can be set to put out a downmixed stereo PCM digital audio output. With a 96K 24 bit DAD disc, it is usually a downconverted 48K, 24 bit PCM digital output, as most D/A converters cannot handle 96K. At the same time, various clocks and data lines feed a low-cost Digital-to-Analog converter within the unit, supplying Right and Left audio outputs. In most models, these outputs are based on the downmixed stereo output on movies and on the true 96K output on DAD. Some models contain a Dolby Digital processor internally. Now the front channel D/A converters are sent the decoded Dolby Digital front channel information, at the highest sample rate available on the disc, rather than the downmixed stereo content.
We can add a digital output that grabs the signal before it gets downmixed to 48 kHz, so you can enjoy the superior sound of 96 kHz 24 bit sound.
The three main benefits of the DVD upgrade
1. The DVD upgrade provides the same data being sent to the internal front channel DAC to the new digital output without downconverting. As a result, decoded 96K Dolby Digital can be listened to for the first time with your own outboard DAC. (See the Link DAC page) DAD discs can also be heard at the true 96K sample rate.
2. The innovators in the high-end community have recognized the advantage of allowing the user access to this digital data, so it can be processed or recorded in the digital format. For any product to receive Dolby approval, significant downmixing, and bass management requirements must be met. They absolutely necessitate additional unwanted analog stages and filters which degrade the quality of the original audio. Only this DVD upgrade allows you to bypass this otherwise mandatory processing.
3. Also included with your upgrade is a re-clocking circuit, for jitter reduction. With any digital source, clock jitter degrades the overall audio experience. DVD players are known to have even more jitter than CD players. Jitter reduction improves the sound by clocking the data into the D/A process more accurately.
What this upgrade does not do
This upgrade only outputs DVD audio. No output is provided when playing standard audio CDs. This is because the jitter reduction is optimized for the higher frequencies of DVD. Use the digital output provided on the player for CD's. Be sure and run it through a Digital Director (or other jitter reducing devices) because no jitter reduction is done in the DVD player. The DVD upgrade does not output data. Neither DTS nor Dolby Digital data can be received from this output. Again, use the provided output for data. These are also improved by the Digital Director.
Connections to the DVD Upgrade
With this new upgrade, your DVD player can be attached to an external 96KHz D/A converter like the Link DAC. Because of the high frequencies involved, a good 50ohm or 75ohm digital cable should be used like the MSB Digital Audio cable. No jitter reduction or switching products such as the digital director should be inserted in this 96K signal path only in the normal digital (48khz or 44.1 khz path).
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