Is this Computer Audio 101?

[Norton]

In response to a recent thread asking about the merits of Computer Audio ("CA") vs. CD, I was surprised to note that most of the initial replies cited the convenience of CA over CD but said nothing about relative SQ.

 

I made the move to CA 5 years ago largely influenced by articles citing the improvements in SQ to be had from ripped CDs playing from hard disk or SS media compared to an optical CD drive. Indeed I found this to be true when comparing (on my Oppo) the same disc ripped and played via network share or thumbdrive vs. the original via the Oppo's optical drive. To me there were noticeable gains in detail retrieval and a sense of "airiness" to the sound which moved a little closer to (for me) the "gold standard" of vinyl.

 

I have no real technical knowledge, but when first starting out on CA, my understanding for the reason for this was that when ripping a CD, the software (EAC in my case) takes multiple readings of the data and compiles an optimum copy which is then further verified against the accuraterip database of existing optimum copies, vs. CD replay which just has one go at reading the data in real time using a compromised optical/mechanical device.

 

My question then is whether there is fairly universal agreement that i. ripped CDs do sound better and ii. if so, it's for the reasons as I understand them? A bit more info on what happens when ripping would be interesting too.

 

Thanks

[blownsi]

Whether it's universally known or not depends on your audience. I think it's pretty well known that a bit perfect rip is going to yield better results than a scratched CD. Beyond that, there are many other factors that come into play. While CA can best even a great CD player I would not say that all CA does. In fact a good friend of mine uses his Mac Mini for convenience but for critical listening much prefers his Audio Research CDP even when both played through the same DAC.

[Jabs1542]

Keep in mind that a lot of what you are comparing are the different DACs, this is what you are hearing. Though it is true that an accurately ripped CD has corrected all of the bad data it would take a lot of bad data for a good spinner to start sounding bad due to the data itself - once again, you are "listening" to the DAC.

[alfe]

 

Your Oppo is a blu ray player and as you see in this diagram you need aperture filters to avoid spherical aberrations when a CD is read.

These filters are source of noise introduced in the HF signal.

[krass]

 

Your Oppo is blu ray player and as you see in this diagram you need aperture filters to avoid spherical aberrations when a CD is read.

These filters are a source of noise introduced in the HF signal.

 

alfe, how does the use of aperture filters on a 400nm signal add HF noise in the kilo- or even mega-hertz ?

to me the optics simply recover a nominal beam shape for the different sized pits, but the output clocking is at such a low relative frequency I can't see how the optics can contribute to any HF contribution......

 

if an explanation is not too unwieldy I'd be interested to learn...... (my only experience is with coatings for UV damage protection, hence the ignorance),, mike

[Fitzcaraldo215]

I do not listen to CD's but I do extensively to ripped SACDs and other hi rez sources in Mch. A number of friends and I have all done comparisons between an Oppo 93 or 103 or Sony 5400 with the original silver disc vs. PC playback of the rip, each via HDMI into the same playback system. These friends include two quite noted equipment reviewers for top magazines, one of whom also does recording reviews for several magazines. Our unanimous conclusion: the rip sounds slightly but noticeably better with consistency from disc to disc. I will spare you all the adjectives describing in what way it sounded better. I also do not want to overstate how much better it sounds. It is not night/day.

 

I have also seen the same conclusion reached by a noted recording engineer about his own recordings, and a number of others online. The best theory seems to be that reading a hard drive is much easier than is a hard working laser mechanism servo-tracking a silver disc with possible power supply modulations involved. We do not think error correction plays much, if any, role in the comparison.

 

It is also possible that different players might stack up differently in this comparison. But, that is not of interest to any of us. We are all convinced that computer audio is the way to go and it involves no sacrifice in audio quality. In many cases, it is an improvement.

[alfe]

alfe, how does the use of aperture filters on a 400nm signal add HF noise in the kilo- or even mega-hertz ?

to me the optics simply recover a nominal beam shape for the different sized pits, but the output clocking is at such a low relative frequency I can't see how the optics can contribute to any HF contribution......

 

if an explanation is not too unwieldy I'd be interested to learn...... (my only experience is with coatings for UV damage protection, hence the ignorance),, mike

 

The diffraction created by these filters have a direct influence on the photo detectors, this detectors not only reads the signal but also serves to sense the location relative to the ridges and correctness of the focus.