hopefully someone can answer my question:
what are the DAC's quaility in the average DVD player compared to that of a CD,
so even if you are listening at 96/24 is there any real world difference because
of the conversion, i heard the DAC on a DVD are worse then a CD?
i know the question is like 'how long is a piece of string'?
i,m just looking at the average household DVD player (not audiophile stuff)?

so

I doubt that either one is consistently better than the other. As for sampling rate, I think that most players already oversample the data before sending it to the DAC, not because it makes the sound better, but because it makes the analog electronics cheaper.

Hard to compare maybe, CD player process 44.1kHz/16bit , DVD players mainly 48kHz/16or24bit though most are capable of 96kHz/24 and 44.1/16 too. Then DVD-A players support 88.2kHz on top of that.
Just to show this are really different DACs.

Older CD players often had tricks too improve the decoding (oversampling, noiseshaping) that you don't find on recent ones.

BTW I prefer to connect digitally to my receiver and use the DACs there.

I doubt you will be able to hear any difference.

It's not that hard to make a good DAC. It is NOT difficult to generate very-accurate low-level analog signals with a DAC. (i.e. You can hook-up two resistors to a battery and generate a very accurate one-microvolt DC signal.)


On the other hand, an ADC is more difficult to design & build, because you are trying to detect/read very low-level analog signals. (i.e. If you amplify that one-microvolt signal back to battery voltage, you will get some noise & drift.)

The same is true with the filters....

The output filter on a DAC has to filter-out the 44.1kHz or 48kHz clock frequency, while passing ~20kHz audio... Easy! (This filter is part of the analog output circuitry, and it may generate some noise.)

On the other hand, the ADC input filter has to filter-out any audio above 22.05kHz or 24kHz, while passing ~20kHz audio. This is more difficult, as it requires a sharp filter that probably starts rolling-off before 20kHz.

I think you missed something ... the filter after the DAC also has to filter out everything over half the sample frequency, so 22.05 or 24 kHz.

A recent test carried out by Silicon Chip magazine (an Australian publication) found that the switch-mode power supply in DVD players produced very low level hum due to grounding methods. CD players generally did not have such problems. Obviously there will be exceptions to these findings.

Once the signal is digitized, there is no "data" above half the sample rate. That's the whole idea behind the Nyquist Theory... You can't get any signal through the system that's above half the sample rate. There is no data above 22.5kHz on a CD... It simply cannot exist!

There may be some clock noise (sample rate frequency) leaking into the analog stage. And, there will be harmonics, but (at half the sample rate) the first harmonic is up at the sample rate.

The DAC works by "connecting the dots" in order to "draw" the wave. At half the sample rate, you get one "dot" per half-cycle which represent the positive and negative wave peaks*. A higher frequency would require information between the dots (between the samples).

Aliasing is a side-effect of trying to "push through" signals higher than the Nyquist frequency. This occurs during the digitizing process (at the ADC stage). The above-Nyquest signal is completely missing from the digitized data (replaced by the lower frequency alias). ...Aliasing is not an issue for the DAC.


* This value represents the peak of the reconstructed wave. At these high frequencies, it will NOT accurately represent the peak of the original wave, unless the ADC clock was lucky enough to line-up with the signal peak.

would it be the case then, that i should not buy audio on dvd's as its all hogwash 'so to speak'...
the whole issue of high resolution reproduction doesn't add up, cd is the furthest we can go in quailty?
would this be the case?