If you have a "kick booty" DAC, does the transport


really matter as it is just a "reader" correct. Am I over simplifying it. When you plug your player into an outboard DAC don't it bypass the internal dac and stuff and shoot it to the outboard? Isn't the laser just reading the 1010101 on the disc and shooting the data to the DAC? If this is true can't a Joe just get a whatever player with coax/i.r./esbu out and just invest in a high horsepower DAC?
mtandrews
i am not so sure that data retrieval from a hard drive is any more reliable than a cd transport when the quality of the disc, laser pickup, and spinning mechanism is the same. according to my very limited knowledge of electronics and computers, read and write errors occur often when spinning a hard drive, although we may not notice the effect of some (software hiccups, delays, crashes...). i believe there is no device that guarantees perfect data transfer available for consumers as of yet.

elements that i think are crucial for data retrieval are:
1. disc quality and condition
2. reading mechanism (laser)
3. speed and stability of spinning mechanism
4. power management
5. vibration control

please correct me if i am wrong.
Keep in mind that the actual electrical signal carrying the data from the transport to the DAC is an analog signal that is sampled at intervals by the DAC. Any corruption of this analog waveform will alter what the DAC "sees" on the link, especially the signal timing, the width of the pulses and the voltage during the sampling windows. Any variations in these can produce jitter (timing variations) in the recovered signal. This amounts to a transformation of amplitude variations in the analog signal to frequency changes in the digital signal. A lot of work has gone into minimizing these effects, but we're still not all the way there yet. For instance, the quality of the transport's power supply will have an effect on the accuracy of that analog signal carrying the encoded bitstream. Think of the output stage of the transport as the output stage of an ultra-high frequency preamp, and you'll start to get the picture. There's a lot more involved than the 1's and 0's.

I use a kick-ass DAC by anybody's measure, an Audio Note 4.1x Balanced Signature worth over $20K, and it makes the sonic defferences between transports and digital interconnects all the more more obvious. I recently upgraded my transport and interconnect from a a $5K combo to a $10K combo, and the improvement was striking.
Gliderguider, doesn't the DAC convert the "1" and "0" into analog signal. Afterall DAC is digital-to-analog converter. I must be missing your point about the already analog signal from the transport to the DAC.
Svhoang,

It's actually pretty complicated. At every stage in both the transport and the DAC, digital information (conceptually consisting of 1's and 0's) is superimposed (or "rides") on a modulated analog carrier signal. There is no such thing as a "pure" digital signal in electronics - a digital signal is really just an information-processing abstraction.

The process of digital to analog conversion you describe is better thought of as taking a very high frequency modulated analog signal coming in from the transport, extracting the digital information from the analog carrier, processing this information through the necessary filters and producing a reconstruction of the original sound pressure waves (the "analog").

The point is, at every stage in the process, from the pits on the CD throught the transport, the cabling, and all the circuitry out to the output jacks on the DAC, the signals are analog. The digital information rides along on these analog signals as a passenger. Anything that can corrupt an analog signal can affect the digital information it carries.

The idea that there are somehow 0's and 1's flowing around inside a "digital" component is unfortunately a massive oversimplification, one that leads to notions like "bits are bits" and "the quality of the transport doesn't matter because it's not analog".

It's all analog. Everything matters.