How is CD playback via optical connection?

[sologemini]

I have been playing CD's and DVD's using the same connection (optical SPDIF) to my receiver for a year now. That means I am using the D/A converter in the receiver instead of the one in the sony DVD player. I have done the comparison between digital connection and analog connection(w/ regular stereo RCA cables, of course) and the sound of digital connection is better indeed. A friend of my listened to it and said that meant the D/A converter in the Marantz receiver is better than that in the Sony DVD player obiviously and if I upgrade the sony to a Marantz CD player and use the analog connection it would be EVEN BETTER! His reason is that the converter in a good CD player should be better than that in a receiver because it's dedicated for two channel audio instead of H/T. Is he right?

Also, is there any difference in terms of quality between the digital output of a good player (marantz) and an average player(sony)?

[cornwaller]

Hello,

Your friend is both right and wrong. If life was simple and all variables were linear then he would be correct. However there to many things at work here to make such a cut and dried decision. The circutry in the boxes has a lot to do with it. Inside there are things like a digital signal demodulator and a microprocessor that could be lacking in one and super in the other. The elegance of the circut, the sampling rate and the number of data bits addressed at a time will make a difference also...and all these things will change with a different model be it sony or marantz or rotel or whomever. For example everybody has a tendency to chase larger numbers--"if an 8 bit dac is good then a 16 or 24 would be much better"! Well Bob Carver is of the schoool that nothing is better than a 1 bit dac. The reasoning is that if you sample a 16 bit chunk of data at one time there is more room for error (this is where the microprocessor does it's job) than if you sample one bit at a time. I think he's correct.

There is no simple answer as you can see...and don't be so quick to write-off sony. Just about every engineer that has heard their cdrw, I think the model is 660; has said that it has the best dac they have ever heard and this unit can be had for about 700 bucks!!

The best you can do is trial and error after you have done some damn good research.

Hope this helps,

Cornwaller

[whell]

Other points to ponder:

Its not always just about the CD player. Any audio component is a series of design successes and compromises. If audio and design engineers were left to their own devices, we'd have much different equipment in the marketplace today. However, every audio company also has marketers and accountants, all of whom have their own agendas for production cost management and delivering products at certain price points.

All of this is to say, for example, that the DAC in any given receiver and CD player could be quite similar, but if there is a jittery transport on the CD palyer, you'll never hear the DAC on that player in full bloom. Conversely, the receiver could have a lousy preamp section, or poorly soldiered connections between the DAC and the preamp, and you'd never hear the DAC on the receiver correctly.

Both my Adcom CD player (5 disk) and my NAD DVD player (single disk) have Burr Brown DAC's, but sometimes the NAD just sounds sweeter playing CD's. Don't know why, really. Transport? Op amps? Same brand/make of analog interconnects used to connect each component. I guess that's what makes this hobby so much fun, but it can drive you nuts at the same time!

[sologemini]

thanks alot, cornwaller and whell

I have to say both of you are quite right. Now I can see that when you do analog signal processing, there are a million factors affecting the final sound coming out the speakers so it's difficult to judge the DAC based on the limited experiments I have done.

Then what about the my second question? As I understand, the digital output should give the signal which is the digital information recorded on the cd so there is no quality factor involved. it's either right or wrong, isn't it? If so, the digital output of different players should give the same digital signal as long as the disc is the same, right or wrong? Or maybe a good player makes less mistakes when reading a disc. I guess that's why cd/dvd player advertisments alsway say something like "precision optics".

Happy new year!

[whell]

>>Then what about the my second question? As I understand, the digital output should give the signal which is the digital information recorded on the cd so there is no quality factor involved. it's either right or wrong, isn't it? If so, the digital output of different players should give the same digital signal as long as the disc is the same, right or wrong? Or maybe a good player makes less mistakes when reading a disc. I guess that's why cd/dvd player advertisments alsway say something like "precision optics". <<

Laser pickup and transports vary widely in quality among CD players. This can account for signal loss in lower quality players, and genrate audible differences.

I'm not one that subscribes to the idea that spending $150 on an optical cable is going to produce audible results versus a $30 Monster cable, however. Opinions on this vary widely, however.