Digital Playback Comparison


Which sounds better: Original CD, CD burned from harddrive, playback from computer HD through USB, or optic cable, or Airport Express? I cleaned my contacts, installed NOS Amperex tubes in my preamp, had new tubes installed in my Trivista SACD/CD player, and had a go at a comparison test for these playback methods. The HD used was from my MacBook Pro. The piece of music used for a comparison was the Hallelujah chorus from Handel's Messiah, Solti and the Chicago Symphony Orchestra and Chorus (Decca 1985). See my system for equipment used. The USB playback was via a HagUSB via S/PDIF into the Trivista coax input. Here are the conclusions, going from best to least good sound quality:

1. (Tie): HagUSB and Burned CD (CD was burned from HD at 4x, from Apple Lossless file). I couldn't tell a difference between these two after extended listening including other music besides the test music. Great dynamic range, wide and deep soundstage, a "rightness" to the sound (at least within the limitations of digital) that made you want to quit analyzing and just listen.
2. Original CD. I read somewhere recently (some of you might know the source) that there is an explaination for why burned CD's sound better than original, but until I made the comparison, I was skeptical. The original had a slight loss of "presence", and seemed slightly compressed compared to the #1 playback methods.
3. HD through toslink. 1 & 2 are closer in sound than 2 & 3. There is a noticable shrinking of the soundstage and air with the optic cable. The cable is a good one--Van den Hull glass cable with mini-plug out from Mac. I was disappointed in the sound from this method.
4. Airport Express and optic. A significant drop in sound quality here. If you have been using this method I suggest doing what I will now do which is run USB out of computer to HagUSB ($119) via long run of coax (Canare for me) to your DAC. The Airport Express is OK for "working around the house on the weekend" listening, but is a serious compromise from what you can get with only a minimal incremental investment.

Notably absent from this comparison are music servers, or a good quality USB DAC, or good reclocker/converters that could be used with a computer HD and conventional DAC. Hopefully someone else can do comparisons of the burned CD with some of these methods to see what is the best sound for, let's say, a $2000 or less investment (obviously not including the cost of a computer). That is a level that many of us might be willing to make if there is a significant improvement over the #1 methods above.
bruce_1
Johnnyb53 - your understanding of USB is wrong. Except for asynchronous interfaces, most USB intefaces are synchronous, and depend on the rate of the datastream in real-time. The thing that makes some USB converters better than others is the chip that is used for the conversion, which can lower jitter significantly, the clock in the converter, and the implementation, or design.

Steve N.
Empirical Audio
steve:

admittedly, i haven't read much on the topic, and i generally only listen to original CDs, so the issue has not really come up for me. however, as mentioned in my own experience, the few times i have compared a wav copy with the original, i did not detect any differences and i was looking for them, as that was the purpose of the comparison. so i would say thatg if there is reduced jitter on a CDR version, it appears that the improvement may not be audible (at least some of the time).

vcoheda

I’m not as technically oriented as a good amount of the posters here… I only know what I’ve done, and what I can audibly feret out over a fairly lengthy time of ripping and burning comps and dupes.

I have no decent path just yet to compare HD tracks via USB just yet… I will have an outboard dAc soon however with which to compare non CD/CDR music, shortly.

That being said, I've personally found that there are audible differences in copied & burned CDR vs. Store Bought (origrecorded) CDs. Many times the orig, store bought is better…. But not always.

Sometimes the noticeable diffs one expects to hear in a duplicated disc aren’t there at all. Occasionally, the diffs are so subtle as to passs without detection for a good while… so remote a quirk or slight is the change in the dupe.

I’ve found some conditions play a fair enough part in the reproduction of CDRs too, such as one’s choice of blanks, ripping speed of the orig disc onto the HD, burning speed, and the burner as well. In fact after adding my PC to an inexpensive PS Audio power filter another level of improvement occurred. Using some isolation devices under the tower helped too. Cooling the CPU also is a real gainer.

BTW Physically heavier orig CDs do better overall during the whole of the process. IMO.

All of these changes played either marginal, or just couldn’t help but hear it changes. A nagging notion for me is I’ve always used Sony CD rom drives, or DVD rom drives to rip and burn with. One of my PCs has a different type burner and I’ve done some comparisons between the performance of both in various fashions, rip with one, burn with the other… same same… different CDRs, etc.

It didn’t take much to discern which was the better unit. All else being the same during the process, the Sony DRU 800 won hands down over the Optiarc 3750A DVD burner. The Sony DVD 510A was I believe better still…. But I did that one in finally some time back.

Using the Apple Lossless codec, using error correction, ripping & burning at 4X, and simply sticking to the blanks acceptable to the burner in question have served me very well.

Much of the audible diffs or losses, occur in the lower regions delineation or articulation. When noticeable losses occur it usually is in that area. It does seem to depend upon the bass info being burned. Very busy or synthesized tracks which contain subtle shifts can be blurred now and then during copying.

Trust me here, I can’t recall how many times I’ve played a disc and wondered when or where I had bought it, only to find out I had made it myself!

Also, dedicating the PC more so to burning, via eliminating background services, processes, and closing out apps normally running in the sys tray helps, as does ensuring the burned tracks are all the same file types. The bit rate of them doesn’t seem as important. Chalk that up to the software most likely. Separating drives onto differing IDE channels was a positive move too, but only just.

When I rip or burn, it’s a dedicated event. I’m doing nothing else with the PC.

Making exact copies using NERO has proven repeatedly the best path… either to HD and then CDR, or marginally better, CD to CDR immediately, using two drives at once.

Mixing up varying file types such as mp3, WAVE, etc, during a compilation, does seem to mess up things now and then at the initial opening of the track. When two differing file types follow one another, for example things have a better chance of going south. I’ve completely quit doing that sort of arrangement altogether now.

Does Oppo make a CD burner? They should if they don’t.

FYI…. Much of these tests are really blind tests…. Though not by choice.