What is a CD transport?
Oct 21, 2003 at 6:05 PM Thread Starter Post #1 of 13

GlowWorm

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Yes, I was wondering exactly what a CD transport is, and what are the differences,and advantages/disadvantages compared to a regular CD-player? Thanks.
 
Oct 21, 2003 at 6:16 PM Post #2 of 13
The transport is merely the drive with digital output - so the dac part (digital analog conversion & analog output section) has to be added externally. The advantage is the same as with getting a pre-/power-amp combo instead of an integrated amp: More choices and more chances to tailor sound and features to your needs.

Greetings from Munich!

Manfred / lini
 
Oct 21, 2003 at 6:30 PM Post #3 of 13
Think of a transport as a cd player without the internal digital to analog conversion or analog output stage. A transport is designed to work with an outboard digital to analog converter (DAC)

The transport includes the following basic parts: All these parts are found inside of every cd player as well. The list is not exhaustive.

1. turntable mechanism / laser assembly (most are produced by major Japanese manufacturers like Phillips and Sony)
2. servo (chip that operates motor assembly to tell the laser what data to read)
3. Clock, which is an oscillator that controls the rate of data flow. The clock may be integrated onto a digital receiver chip.
4. Digital receiver chip: My understanding here is that the receiver chip sets the data stream to a certain protocol for delivery to the DAC (different data stream protocols would be S/PDIF or AES/EBU). Also controls servo chip.
5. Power Supply for the above.

The transport will include several types of digital outs for use with a variety of DACs. The advantage of the transport lies in its flexibility to use with other components. For example you could have an SACD transport going to seperate DSD (SACD) and PCM (redbook 16/44) Dac's. The main advantage in sound quality is the isolation of the mechanical parts from the electronic parts. A dedicated transport is not necessarily better, certainly many of the most esoteric digital combinations are separate transport/DACs.

Disadvantage: You have to pay for a separate chassis/power supply and digital cable so it will be more expensive. There are also other issues with data communication like clocking that a more qualified person will have to answer.

The DAC controls the digital to analog conversion and includes an analog section that increases the voltage of the signal to line level.

Did I miss anything?
 
Oct 21, 2003 at 7:01 PM Post #4 of 13
In very general terms, a CD transport can be any CD player that has a digital output. If you connect an external digital to analog converter to the CD player's digital output the CD player in effect then becomes a CD transport, simply put. It acts as a transport mechanism to send the digital information off a CD to an external digital to analog converter bypassing it's own digital to analog converter section.

Now there are, as other posters have pointed out, some CD players that are only a transport in that they only have a digital output to send the bits to an external digital to analog converter, and do not themselves have an internal digital to analog converter. They truly are dubbed a "CD Transport."
 
Oct 21, 2003 at 7:26 PM Post #5 of 13
Thanks guys for taking the time to explain it to me.
smily_headphones1.gif
 
Oct 21, 2003 at 7:53 PM Post #6 of 13
Quote:

Originally posted by Canman
. . . major Japanese manufacturers like Phillips . . .


My Dutch friend would kill you right now. Philips is a Dutch company based in the Netherlands.
smily_headphones1.gif
 
Oct 21, 2003 at 8:52 PM Post #7 of 13
Quote:

Originally posted by Hiker
My Dutch friend would kill you right now. Philips is a Dutch company based in the Netherlands.
smily_headphones1.gif


Netherlands is in Japan, right?


J/K, props to those Dutch for their excellent transports
wink.gif
 
Oct 21, 2003 at 11:21 PM Post #8 of 13
Yeah, they do have some good transports. I was acutally surprised when I first learned that Philips was a Dutch company. I found out last year when I was shopping for HDTVs.

Well I guess thats enough of my thread jacking for now.
very_evil_smiley.gif
 
Oct 22, 2003 at 6:04 AM Post #9 of 13
Quote:

Originally posted by Hiker
Yeah, they do have some good transports. I was acutally surprised when I first learned that Philips was a Dutch company. I found out last year when I was shopping for HDTVs.

Well I guess thats enough of my thread jacking for now.
very_evil_smiley.gif




mmmm Philips HDTV. i saw one at best buy and it was the best picture i have ever seen on a tv to this day. too bad it was like $8k. id rather have a motorcycle
 
Oct 23, 2003 at 11:47 AM Post #10 of 13
FWIW I've had a few CDPs / Tranports over the last few years and swear by the Philips tranport mechanisms.

I'm currently using a Rotel RDD980 with a Philips CDM9 and a Krell DAC and the sound is wonderful, perhaps only being let down by the PSU in the Rotel.

The current CMD12 and the VAM12.. Transports as seen in the Naim CD5 et al will go up against anything!




The only issue with using a seperate Transport and DAC is the slight mismatch of the internal clocks which can cause Jitter (slight loss of detail and smearing of soundstage/depth). Thi can of course be fixed by the use of a Monarch DIP or Theta TLC or a Jitterbuster or the like.
 
May 19, 2009 at 2:21 PM Post #12 of 13
The drive/unit physically spinning and reading the data bits from the CD, outputting the data digitally through an S/PDIF (optical or coaxial) connector.
Unlike a CD player which have a built in DAC and output analog audio.
 

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