Does the quality of a digital signal matter?

I have not as I've only had it for about a day, but I'll give it a shot. I wouldn't purchase another CD player for the single purpose of making regular CDs sound slightly better, but if I determine that SACDs are a significant improvement it would be worth the upgrade that may do both.

Are you suggesting that a large portion of the SACD improvement is the player iteself and not the additional data?

That's exactly the question. I would suspect that the vast majority of audiophiles use analogue connections to avoid ever having to make the transition into a digital format.

If a CD player is doing nothing more than reading the digital data (i.e. ones and zeros) on the disk and sending the information to another component for the D/A converstion what could effect the signal?

Do you insist on having a $1,000 CD drive in your computer to ensure that you have an accurate copied disk? How about burning a disk on an external drive using a USB cable, is there any risk of not getting a perfect duplication of the original without getting an error?

"Apples and oranges......

I suggest you compare the two players just using the CDs you have now. You should be able to hear a difference between the two players."

Why would the SACD player make standard CDs sound different? The SACD has a much higher sampling rate that should be responsible for the vast majority of any difference. I have burned some standard CDs from the hybrid SACDs and I'll probably be getting an SACD player fairly soon. Everything is more crisp and detailed.

From How Stuff Works:

"In analog technology, a wave is recorded or used in its original form. So, for example, in an analog tape recorder, a signal is taken straight from the microphone and laid onto tape. The wave from the microphone is an analog wave, and therefore the wave on the tape is analog as well. That wave on the tape can be read, amplified and sent to a speaker to produce the sound.

In digital technology, the analog wave is sampled at some interval, and then turned into numbers that are stored in the digital device. On a CD, the sampling rate is 44,000 samples per second. So on a CD, there are 44,000 numbers stored per second of music. To hear the music, the numbers are turned into a voltage wave that approximates the original wave."

What this means is that until the numbers of the digital signal are converted back to a analog voltage wave via a D/A converter the only thing that matters is that the signal be transferred.

Maybe this is my my CD player recommends using a digital connection to my receiver rather than analog. At my equipment level he preservation of the analog signal isn't able to match bypassing the component all together and "shortening" the path of the analog signal.

I'm glad to see some objective insight on this subject. Keep in mind that I'm making a clear distinction between the two cases of having analog vs. digital being output from the CD player.

In my mind, a clean analog system would be the following:

(1) turntable - pre-amp - amp - speakers

In the digital world it would look like one of the following:

(1) CD player (DAC) - pre-amp - amp - speakers

(2) CD player - seperate DAC - pre-amp - amp - speakers

(3) CD player - integrated DAC/amp / receiver

I suspect that having an analog signal go through my home theater receiver would probably cause more degradation of the signal quality to nullify any advantage of an auidophile grade CD player.

I do not think that timing would be an issue for CDs as most can read a disk much faster than is required. This is was is known as a buffer and we all know what happens on youtube when the buffer isn't adequate.

My thought is that someone that will be using a home theater receiver (possibly other options depending on budget) would do better to put their money towards a better receiver and speakers than to invest in an expensive CD player and increase the number of things in the analog signal stream.

The issues assocated with degradation begin wherever the D/A happens.

It's interesting that the majority of arguments for the quality of a digital signal making a difference are directed at the D/A conversion process which is exactly where everyone agrees that the signal can be influenced.

It also interesting that another Electrical Engineer (EE) agrees with what my friend explained to me.

I may be over simplifying this a bit, but it sounds like the proximity of the components that "read" the CD can have an effect on the analog signal created in the DAC. Would this be justification for a completely seperate DAC?

How does this relate to a Toslink cable that is optical?

Almarg - Here is a response from my EE friend that I've been discussion this topic with at work.

"One of the most important factors discussed is "the value of the logic threshold for the digital receiver chip at the input of the dac" which, and this is important, supersedes ALL OTHERS in properly designed electronic equipment. If it didn't, the computer you are typing on would not work, the key-strokes would get lost, data you receive over the internet would be incomplete, pixels would be missing from the image in your video screen--ALL of which operate at WAY higher frequencies than any CD audio signal. Compared to modern computers, digital audio is simply rudimentary. If the audio equipment cannot transmit or identify logic signals that are above the background noise (all other elements discussed fall into this category) than the equipment in question is simply junk. I could, in the digital electronics lab at school, design and build a digital data transmission device and associated data receiver that would operate at 1MHz (far above any audio signal, but low frequency for digital electronics) and not lose a single bit of data.

Again, everything mentioned is real and true, but IS NOT A FACTOR in properly designed and built equipment. It is FAR more applicable to things like cell phone and computer design, and if the electronics industry were unable to overcome all the factors discussed in mere audio equipment, then a working cell phone and 3GHz processor would simply be pipe dreams.

As far as the SPDIF issue addressed in the linked article is concerned, it too is correct, but not a factor in your system. If you think it might be, switch to an optical cable or HDMI and see if you can hear a difference. I bet not. The information getting to the DAC in your amplifier will be bit for bit identical. If not, you have broken equipment."

On thing to note is that the information in one of the long and detailed articles linked in this discussion is 17 years old. My EE friend pointed out that a 2x CD player was a big deal 17 years ago. I would hope that many of the problems described have been reduced or solved by now. When it comes to electronics, 17 years is a very long time for technology to develop.

I picked up an SACD player from a friend today to borrow for a few days. We'll see how much difference there is once I get a copies of a single album in both formats. It'll probably be Nora Jones since I already have the CD and know it's a quality recording.

Jea48 - I currently have the SACD player hooked up in 2 channel analog mode so I'm not even listening to the multi-channel versions. I think most, if not all, SACDs have stereo versions. I don't really care about the multi-channel because my rear channel speakers are no where near the qualility of my Focals.

2 channel standard vs. 2 channel SACD is what I'm comparing. I'm planning to swap the disk and compare the result of standard CDs on both players, but a toslink vs. analog isn't really an equal comparision.