Do Transports Matter???


I borrowed an outboard D/A from a friend to try in my system. My intent was to hook the analog outs on my CDP to one input on my preamp and the analog outs of the DAC to another input so I could a/b my player with and without the DAC. However something is wrong with the digital out on my player because I couldn't lock a siginal with the DAC. So I grabbed my pioneer DVD Player and hooked it up as a transport. Everything sounds awesome, made a big difference in my system(won't go into details). The outboard also puts the DVD players onboard DAC to shame(well duh). But this of course also made me wonder if using a different transport(my cdp if it worked)would make any difference?? In reality the DVD player is reading the CD and sending 0s and 1s to the DAC where its reclocked anyway. I know that sometimes little things make a difference, even though on paper they shouldn't. Being this is my first expirence with an outboard DAC, I am just curious if what you use as a transport makes any difference
brianvoelz

Showing 6 responses by redbeard

Oh PLEASE!!! Now I've heard it all! The AC cord on the transport makes a difference???

The ONLY thing that makes a difference is the stability of the clock/power/ground at the last digital element prior to the actual D-to-A. (I'm talking downstream if the digital filter here.) Anything upstream of that ONLY makes a difference if it affects in some way, shape, or form the clock at that critical point.

You can have jitter up the ying yang upstream, but as long as proper care has been taken to provide a jitter free clock at the LAST register, upstream crud doesn't matter. Of course the power and ground at the last register also matters because noise on the power or ground cause fluctuations in the switching threshold of digital devices, but even that can be minimized by providing rapid rise and fall times on the clock.

If someone hears a difference when they change a transport or digital cable they should realize that what they are actually hearing is a byproduct of insufficient filtering or isolation IN THE DAC!!!!!!
Mejames,

I've heard that painting you room a different color also improves the sound. Have you tried that?

For anyone who is interested in the engineering principles behind DACS (as opposed to VooDoo engineering) here is a link to a great website:

http://members.chello.nl/~m.heijligers/DAChtml/dactop.htm

And one on a jitter free PLL:
http://members.chello.nl/~m.heijligers/DAChtml/PLL/PLL1.htm
Mejames,

I'm afraid you are right. This forum may not be the right place to espouse science and engineering. Some people just don’t believe in such things.

If you look at my first post in this thread you will see the following sentence:

“If someone hears a difference when they change a transport or digital cable they should realize that what they are actually hearing is a byproduct of insufficient filtering and isolation IN THE DAC!!!!!!”

That statement, as well as the rest of that post is pure unadulterated fact. It is irrefutable.

Let me make that clear so there is no confusion. If there is insufficient isolation, filtering, or clock source in the DAC, then crud (jitter) present in the digital input could be coupled into the analog signal path. The common band-aid solution when this happens is to try to reduce that jitter by throwing money at the transport, transport power cable (what a laugh), digital cable, etc. instead of addressing the real problem, which is poor isolation, filtering or clock source in the DAC. THIS IS FACT!!!!!!!

I’m sorry if this doesn’t fit into your perception of reality.
You know, I half expect to hear someone say that they can hear a difference in the sound of a cd after rapidly shaking the cd before puting it into the CDP.
It is normal for people to believe their senses instead of science. After all, there is a lot of historical precedent along these lines. I can imagine the frustration that Aristotle must have felt, after realizing the world was round, as he tried to explain to people that ships only appeared to fall off the edge of the earth as they went out to sea. People believed what they saw rather than science, which they didn’t understand.

The situation that we have been discussing here isn’t much different. We have a group of people who do not understand the science and technology behind digital electronics. They believe their senses, and rather than trying to understand the underlying cause and effect relationships that are responsible for their perceptions, and they prefer to believe in magical and mystical solutions that can not be explained through science.

The technology involved in Redbook recoding techniques is over 20 years old. Today, technology has advanced to the point where CDP technology is literally child’s play in the engineering community. To put it into perspective, in 1982 they were putting 5MB into a 5.25” HDD with 5 platters. Today, they are putting 80GB onto a single 3.5” platter. This is an 80,000+ fold increase in aerial density. Believe me, this wasn’t achieved by relying on mystical effects that we don’t understand. It was based on hard work by scientists and engineers in multiple disciplines. Technology, and our understanding of it, march on. So when someone tells me that there are unexplainable forces at work in the digital end of a CDP, I can’t help but laugh my head off.

There are market forces at work here as well. There is a lucrative cottage industry that supplies the audiophile community with nonsensical accessories. Many segments of this industry would dry up if the audiophile community became aware of the true cause and effect relationships at work in their systems. It is in the interests of these merchants to keep the community ignorant, and believe me, they do their best to muddy the waters.
Now where did I put that can of paint labeled 'transparent, clear, with a deep sound stage'?