How does a Transport effect sound?


hi guys,

Been wondering about this: How does a CD Transport effect sound?  Isn't it just reading the disc and sending the 1s and 0s to the DAC.  Shouldn't every transport sound the same?

Thanks! 
leemaze
I don’t know all the variables involved but I do know from experience that CD transports can and do sound different. Bits is bits?
Background scattered light has not been addressed by any manufacturers, at least not to any great extent. So there’s that. And magnetism and static electricity are still problems, there’s that, too. I suspect maybe “jitter” isn’t the do-all end-all for various problems involved with CD playback. There’s also the nagging question of why they can’t make the clear layer in CDs a little more transparent.

All of these problems are addressed by two current solutions:

1) reclock the S/PDIF output from the transport

2) design a transport using a CDROM and a computer motherboard and memory.  Buffer in memory and spool it out over S/PDIF

And JITTER is the THE ONLY issue with the S/PDIF output on a transport, period!

I am a EE that has designed digital systems for 42 years and have designed dozens of digital audio interfaces including S/PDIF, AES/EBU, I2S, differential I2S, 6 generations of USB, Ethernet.  I know what I'm talking about.

There are obviously other issues that come up if you use the D/A inside the player and the analog outputs.

Steve N.

Empirical Audio

I don’t know all the variables involved but I do know from experience that CD transports can and do sound different. Bits is bits?

Same bits, different Jitter.  Bits are the data, Jitter is in the timing.

Steve N.

Empirical Audio

@audioengr 
I like the compact "Same bits, different Jitter. Bits are the data, Jitter is in the timing." Steve, what stand alone transport do you think sufficiently handles jitter such that the synchro-mesh is redundant, if any? And I second the importance of a high quality SPDIF cable. 

Frankly if you dont spend $20K on a transport, you will not get the kind of low jitter that the Synchro-Mesh can provide.  Even then, I'm not convinced.  dCS Vivaldi, dCS Scarlatti, MBL do not publish jitter numbers and neither does PSAudio for their memory player. The dCS has word-clock input, so it can synchronize to the Master Clock in their DAC's.  So it's the DAC clock that needs to be low jitter.  Simaudio 260D says their "intrinsic jitter" is 1 psec.  I think this means their oscillator spec.  This is not unusual for a good oscillator, however by the time the signal goes out the S/PDIF BNC or RCA, it will usually have 100's of psec of jitter.  My clocks have 1psec of intrinsic jitter, but that's not what I advertise.  I advertise the jitter at the end of a 1.5m cable with a 75 ohm termination.

Steve N.

Empirical Audio