So is this as good as you need for a transport?

I sure agree with that. When digital was new, differences among transports were stark. Now that DACs have improved, differences seem less, but despite my expectations (same as @Rolltide ), I hear differences. When in the early 1990s, I added a Proceed PDT to replace something cheap. I was flabbergasted at how much better the system sounded.

In 2018, my listening is 99.9% file-based, but for years, I kept my Meridian G98 to play discs for visitors. When that died last year, a friend passed along a Marantz SA8260. The Meridian sounded indistinguishable from the home-networked stream; the Marantz, decidedly inferior. Again, not what I was expecting.

It is unfortunate, but this is an area where you need to listen before deciding.

 

I could not disagree more. I have found that no other cable even comes close to the deleterious impact that a badly matched SP-DIF cable has inside of my system.

Honestly I do not understand why this is, because theory would dictate the exact opposite. But the difference when a friend inserted a some special $300 SP/DIF cable inside of my system was absolutely shocking. Everybody could hear it immediately (him, me, and my wife). And no the sound wasn't better, it was actually much worse! It sounded like somebody had thrown some thick wool blankets over while this expensive cable was in my system. And removing it, to replace it with my original cable instantly restored the sound.

I agree, this makes no sense. But I also know that it can make a significant difference, although I have no idea why or how.

 

I'm not sure any theory would really dictate the opposite.

There are two main places that a (relatively) large amount of clock jitter is introduced in the typical transport/DAC system. They both use a phase-lock loop (PLL) for synchronization.

The first is when the data is read from the disc, using a PLL to control disc speed and keep the read buffer filled to a certain level, so pit jitter encoded in the data on the disc will become part of that PLL clock to a certain small extent as it adjusts to keep the data rate constant, and will also wind up in the system clock to a certain smaller extent since it is in the same domain (both can be made very small with careful design and layout).

The next PLL is in the receiver at the DAC input since the SPDIF is (for simplicity) a single line transmission, and the clock must thus be biphase-encoded in the data stream. The receiver circuit attempts to lock onto this datastream using a PLL circuit, which by design usually tracks the incoming signal closely to lock quickly and maintain lock. The tight lock means that it also tracks the clock jitter to the extent allowed by the PLL loop filter, and this SPDIF line can have a lot of jitter in the recovered clock because the rise and fall times of the signal bits are somewhat dependent on the data pattern due to cable impedance mismatches, and bandwidth limitations, and dielectric constants of the cable materials, etc.

So the cable type, and how well the driver and receiver circuit impedances match to the cable and connector types, and a host of other small details will determine how much data correlated jitter gets across from the transport to the DAC. How the DAC handles all that jitter on the recovered clock is another subject, but will influence how much difference one may perceive between different cables and transports.

 

That's a lot of words. Too bad none of them explain why coaxial cable with a 75ohm connector adds or removes jitter from the signal it carries.

 

There's nothing like a good "even my wife heard it!" post.

 

Well, some of them try to, apparently not very well

 

Actually, several years ago I bought a new DAC and in the process drained my audio kitty. I needed an interim transport, and I decided to give the cheap DVD option a go. Since all the heavy lifting is done by the DAC, this should be a no brainer. I had robbed the TV system of a Philips machine we had, and it sounded pretty good. So I got a Toshiba, and it sounded horrible! I also tried a Sony, and terrible results to. I finally found another Phillips, and that worked out the best.

One other thing I found interesting is that many of the DVD players did not output 44.1 kHz. While they may sample that, the ones I was looking at actually put out 48 kHz. You could find it in the menu settings.

I ended up buying an EAD T1000 transport, and that was a far better choice than a DVD player.

 

Are there cables that are claimed to remove jitter? I've never run across such claims, and I'd seriously be very suspicious if a manufacturer did claim such. Cables can only contribute to the total jitter, not remove it. Cable A may have less jitter contribution in a particular system than Cable B. If you have used Cable B for quite some time, then switch to Cable A, you may feel that Cable A has removed some jitter. But, in reality, it has just contributed less jitter than Cable B. Most of us are stuck with RCA jacks on our equipment for SPDIF connections, in which case 75ohm connectors don't exist. BNC connectors do come in 75ohm flavors, but the only gear I have with BNCs use them for Word Clocks - not the actual audio data connector. Danggit!

But, let's just say we do have a couple of cables with 75ohm BNC connectors on it. The one with the wider bandwidth cable will, in all likelihood, contribute less jitter in a system than the lower bandwidth cable.

 

Canare makes a 75-ohm RCA connector. How it compares to a BNC, I don't know.

 

In most cases you won't hear the difference in transports but in some cases the differences can be rather staggering. Why? Well transport mechanisms fall into two general categories. The $4 to $22 range and the $400-$600 range (that is cost just for the transport mechanism).

Since most all CD players in the $300 to $2500 price range use a sub $25 transport mechanism the "transports" would be rather difficult to distinguish so back in the day when I compared a single disc Marantz raved about transport and a Pioneer 100 disc changer into the same DAC and heard no difference and neither did the dealer or anyone else my thinking was why not get all the boatload of features and get the 100 disc player?

Plus when fully loaded it was a substantially HEAVIER transport than the single disc loader.

But you fast forward two decades and hearing much higher end systems and a very good transport like the Audio Note CD Two/II makes a rather substantial difference over the 99% of machines that use the $15 mechanism. Bass, dynamics, music coming out of a black backdrop. The problem is that because it's 2018 and none of the "GOOD" mechanisms are being anymore the price of entry for a CD player using the Philips Pro2LF are likely going to run you $5,000+

And yes it may very well sound better but it's a lot of coin. But it's either a machine like this (there are a few companies like Metronome and Acoustic Plan and Opera Consonance using this transport) or the CD players using an el cheapo mechanism. Some may be a little better than others with various tweaks done by the manufacturers.

Cambridge Audio makes the CXC which is only around $400 (affordable) but dedicated transports are becoming harder to find. I think the Philips Pro2 offers audible gains but at $5k you have to ask yourself if spending an extra $5k on the DAC and going with the CXC would be better? The other factor is if the CXC drive fails it's a $20 drive - if the Philips pro fails (and they eventually fail) then it's $500 plus. And if it is 10 years from now, will there be a replacement part available?

 

The transport mechanism can indeed make a big difference, if you have a really good one. As Richard pointed out, units with good mechanisms are rare, and not cheap. The least expensive one I'm aware of is the CEC TL-5 with their proprietary belt drive mechanism. To the best of my knowledge, the current price in the US is $2800. I have one, and highly recommend it. There is a new US distributor, and at least one factory authorized technician in the US who services CEC, if that is a concern. I've had mine for a year and a half, problem free. It is very well built, the belt is specified to last at least 5 years, and is easily user replaceable, if needed.

 

Simaudio makes a good one, the 260D for about $2000. I have one with the optional DAC. Very nice unit. No SACD though.

 

The CEC TL-5 is now $2800? I have to admit, sound aside, it is way sexier than the Tascam . However, at these prices, as much as I like physical media, I am more inclined to use a computer as a transport.