2. digital
  3. 1165585305

Transport - does it matter to the sound at all?

I wanted to start this thread, to gain some insight into peoples experiences on this subject.
My view: From the outset of CD and digital media, we were force fed the view that 'its digital so always sounds the same whatever' ideology. Remember the jam on the cd, and it doesn't skip. Since these naive beginning we quickly found out it did matter, and the quality of components, interconnects (its wire isn't it so doesn't affect the sound?) and design DID affect the sound. So I firmly believe that a transport does affect the signal quality and final sound output in a big way. There are transformers, capacitors, boards, wires, all the components that have such a bearing on quality output on all the other components in a system. And the motor, the bearings, the transport mechanism, jitter correction, noise, damping, vibration from itself and speaker interaction ALL will affect the sound.

My question, what are the views on this balance between cost on a DAC and the transport. Are many of us getting it wrong bolting on Sony DVD players to high quality DACs? And are many of the 'quality transports" out there just re-boxed philips units. It does appear very few manufactures build their own transports aka Meridain, Linn and Naim to mention a few.

It would be great to see a high quality transport kit out there, which would allow a full transport and kit DIY project, with mods and part upgrades available at an affordable price.

I haven't the money at present to upgrade my DAC, which is an upgraded Audio Note DAC 1.1 and Zero transport, but I am very happy it at the moment as it was a huge jump over oversampling units I had owned previously.
astrostar59

Showing 10 responses by audioengr

audioengr
3,282 posts
 
Jitter is the difference in both Transports and digital cables. Jitter is also a problem with commercial CD disks. Rewriting a disk with a low-jitter writer can be equivalent to $1200 in mods to the transport or a $600 digital cable. See these articles on the subject:

http://www.positive-feedback.com/Issue14/spdif.htm
http://www.positive-feedback.com/Issue22/nugent.htm

As you can glean from the articles, changing transports is not really the road to low jitter, computer audio is.

Steve N.
Empirical Audio
Manufacturer
audioengr
3,282 posts
 
"The wisdom handed down to me from one of the most respected engineers and manufacturers of tube gear was expensive transport and modest dac make for a musical presentation and the other way an audiophile presentation."

This is not wisdom IMO, it is a result of some limited anecdotal evidence. The sound result depends entirely on the designs of the individual components and the parts used therein. No conclusions like this can be drawn IMO. And I would be wary of who you consider wise.....

Steve N.
Empirical Audio
EE with 30 years design experience
audioengr
3,282 posts
 
Astrostar59 - what you must understand is that the Transport primariily has a impact on the jitter. The jitter has a sonic signature that mostly impacts the high-frequencies and the dynamics of the HF. The DAC on the other hand can have an impact on the entire frequency spectrum as well as dynamics top-to-bottom. Noise and distortion are also DAC related. The DAC can also add jitter. Given all of these impacts, I would have to judge the DAC the most important with the Transport/digital cable next important.

Steve N.
Empirical Audio
Manufacturer
audioengr
3,282 posts
 
Still waiting for Alex's response: If it's not jitter what is it????

DSP??

Steve N.
audioengr
3,282 posts
 
Seandtaylor99 - I have customers with these. I have to hear it to believe it.

I've heard a true reclocker, my own Pace-Car. It is still in debug, but amazing sound.

Steve N.
audioengr
3,282 posts
 
Jsadurni wrote:
"Are you saying that the only difference between a good transport and a bad one is in the High frequencies?"

No, the jitter is the difference. The HF are the most noticable effect of jitter.

Steve N.
audioengr
3,282 posts
 
Alex - You claim that ther are other "Factors" than jitter. What are they?

The ability to read disks without error is a capability of even the cheapest $50 transports. What else is there than jitter?

I suppose one other thing could be galvanic isolation, such as with a pulse transformer, but again, even cheap transports have transformers on the digital out.

Edge-rates vary quite a lot between transports, but again, this is manifested as jitter.

Steve N.
audioengr
3,282 posts
 
Zaikesman - I would be wary of drawing conclusions about jitter reduction from a Monarchy DIP. It certainly helps, but as you say, is far cry from elimination of jitter. Even the expensive Big-Ben, which incidently works much better is not jitter insensitive. A true re-clocker with good ground isolation should make even the cheapest DVD player sound like a million bux. Unfortunately, it does not exist.

Steve N.
audioengr
3,282 posts
 
Jsadurni - I have a couple of Off-Ramp customers that are using the Altmann DAC. They seem to like it. I dont really understand what this JISCO thing is. I have reports from some that it is better turned-off. Others seem to like it on. Looking at the parts and board design I'm not impressed and evidently some digital signals pass through a toggle-switch? It may sound good though. Never heard one. The battery power definitely helps.

The only DAC that I'm aware of that uses a true jitter rejection technology is the Lavry. This is sound technical design. Interesting feedback from a customer that upgraded from a Audiophile USB to an Off-Ramp Turbo 2 though. It sounded better, more focused. Maybe it does not reject all jitter? Still one of the better designs available commercially.

Steve N.
audioengr
3,282 posts
 
Seandtaylor99 - I would not put the onus on either the DAC or the Transport. Either can have very low jitter. However, the closer you get to the D/A chip with a low-jitter clock, the better the result. The problem is that most modern DAC chips dont use the classical "word-clock" to actually do the conversion. They more often use the bit-clock or even the master clock, which are much higher frequency. This is why I prefer the I2S interface. It enables all of the clocks (SCLK, MCLK and L/RCLK) to be close to the D/A chip. If the source of these clocks is low-jitter, then mission accomplished. This is what I do in my Pace-Car.

Steve N.
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