Have you guys seen this video on digital audio?

[JZatopa]

I thought some of you guys would like to see this video from Xiph.com on Digital audio signals.

Check it out.

 

[ginetto61]

Very interesting indeed. Thank you for the link !
I have a friend with a very nice analogue set up (and quite expensive as well)
I tried to convince him to make a comparison between the signal coming from the turntable and the same signal digitally recorded at 44,1kHz/16 bit
He did not accept maybe scared by the possible result ... he considers the cd inferior system.
but now I have the answer.
Most probably the copy would be pretty much identical to the original.
Thanks again and kind regards,
gino

 

[DF96]

Very good.

I would take slight issue with his claim that the stair steps are not really there. They are there in the raw output from most DAC chips, but the reconstruction filter gets rid of them. That is what it is there for. Another way to understand this is that the stair steps are the time view of what are images in the frequency view. People who are worried by digital stair steps should never use a simple NOS DAC, as that has no reconstruction filter so the steps are sent straight to your amplifier and tweeters.

 

[JonSnell Electronic]

Very good.

I would take slight issue with his claim that the stair steps are not really there. They are there in the raw output from most DAC chips, but the reconstruction filter gets rid of them. That is what it is there for. Another way to understand this is that the stair steps are the time view of what are images in the frequency view. People who are worried by digital stair steps should never use a simple NOS DAC, as that has no reconstruction filter so the steps are sent straight to your amplifier and tweeters.

The inacuracies are smoothed out with the capacitance of the phono lead and amplifier in most cases using 128bit.
Anyway, why is there such a revolution with Flying Mole and other d type amplification?

 

[Bibliophile]

Thanks for that very interesting link.
It clears up some misconceptions that I had about digital media.

 

[DF96]

The inacuracies are smoothed out with the capacitance of the phono lead and amplifier in most cases using 128bit.

128bit?? The steps are not inaccuracies, they are images. They are not the result of quantisation, but sampling. 1024-bit digital (if it were possible) would still have the same steps. To get smaller steps you need faster sampling. Given that the source is probably 44.1kHz or 48kHz, the only way to reduce the steps is to use a reconstruction filter (either digital or analogue).

Cable capacitance, unless driven from an inadequate source impedance, will not make much difference and anyway is entirely the wrong way to engineer a system.

 

[Xoc1]

Digital Audio is OK!
In theory we should be all listening to wide dynamic range low noise audio.
Instead what we are given is horribly compressed and distorted audio 'Because its sounds exciting for five minutes on the radio'
It's not the recording medium that is wrong, its the way that it is used to give us recordings that are blatantly clipped that is the real problem.
Want to see flat edges on an audio signal - simple just measure the waveform on almost any modern recording!
I know this has nothing to do with digital sampling but the reality is almost any CD I buy has been clipped and distorted to make it louder.

 

[ginetto61]

Also impressive to hear that the old cassettes were 4-5 bit at maximum
if I think that I considered those hifi ...
But now I really wonder if high rez is really needed ... if the redbook format is so good already

 

[Pano]

To get smaller steps you need faster sampling.

I'm not sure I know what you mean. Do you mean smaller steps in time? Smaller steps in amplitude can be had with higher bit depth, no?

 

[dirkwright]

Well, there is a stair step output directly from the DAC chip, which the video ignores, and the other problem is that there is a phase shift introduced by the analog filtering after the DAC.

Of course, in the analog world, there are plenty of phase shifts in the RIAA and NAB compensation networks, so analog systems are no better in that respect.