Differences between cd transports?


Howdy,I borrowed a dedicated CD transport (Musical Fidelity) from a friend. I have found that music sounds much better with his transport than with the CD player I’ve been using to spin CDs. In both cases, I am using exactly the same DAC via the optical out connection from the transport and the CD player. So: is there any rational reason that, using the same digital to analog converter, one CD spinner should sound much better than another?Thanks!  
rebbi
What CD player were you using?
Hey Reb, hope all is well.

Many things might account for one digital source sounding different than another. Jitter is probably the most common culprit. Some DACs can correct for that, others not.

Assuming transports are working properly, there is also often errors in reading optical discs in real time as CD players must do, especially with poor quality, defective, or damaged discs that can affect results differently from transport to transport. Ripping to storage first using good ripping software that can assure high quality rips by detecting errors and rereading as needed.   Streaming  then tends to produce more consistent high quality results compared to reading an optical CD in real time in order to play it. 

Note that just because a CD is or looks new does not mean it is of high quality. You find when ripping CDs to disk that the speed at which the disc can be ripped varies with disc quality and disc quality cannot be determined with visual inspection alone.

Can you elaborate on what the sound differences were and to what extent? Differences in dynamics, detail, sound stage and imaging I am guessing?

Also what is the DAC?

Thanks.
Toslink often sounds worse than coax, in spite of immunity to external electrical noise or not creating ground loops.  It is because optical transmitters are slow.  Light is moving fast, of course, but transitions are slow making moment of detecting threshold voltage vulnerable to system noise.  This will produce slight time variations (jitter) resulting in added noise after D/A conversion.  It is possible that your friend's transport had faster optical transmitters (LEDs) or had less system noise (better power supply, better shielding etc).   Coax has much faster transitions (tenfold), but it has other problems like sensitivity to electrical noise, ground loops and reflections in the cable.
@kijanki 
 
Some DACs perform better with Toslink than USB/coax/etc., so a blanket statement about which input is best for a specific DAC can’t be made. 
Assuming transports are working properly, there is also often errors in reading optical discs in real time as CD players must do, especially with poor quality, defective, or damaged discs that can affect results differently from transport to transport.

What Mapman said.
I’ll add the standard being used to transfer the datastream to the DAC; the use of USB, SPDIF coax, AES, or optical. Also the quality of the cable: ie, how well a SPDIF cable faithfully transfers data without adding jitter.

And IME, the design of the transport; I went from using an NAD CDP as a transport to an ARC which was a major upgrade in SQ, both as a CD and as a transport. My quality of playback increased again since adding a PS Audio memory player.


Some DACs perform better with Toslink than USB/coax/etc., so a blanket statement about which input is best for a specific DAC can’t be made.
That's why I said "often". 
I have an Oppo 105 that I was using with a quality WireWorld toslink. I upgraded it’s input IEC and silver wire to the power supply and later I replaced the OEM power supply with a Linear Power Module, but was not happy with the sound, so I bought a Marantz HD CD 1 to use as a transport. When I replaced the toslink with a TOL WireWorld Coax the Marantz took a giant step forward.

I finally got around to hooking my Oppo 105 back up, this time with the Coax. Coax is so much better on these 2 players used as transports. I doubt there is a transport where toslink would sound better. Some newer high end transports no longer include toslink
Um parts quality and power supply add to why one sounds better than the other, then there is the laser, plus tray loading or top clamp.  For example, a few CD transports have a separate power supply like the old Audiomeca and Metronome ones.  You can read about some of this on the Lampinzator (spelling) website or thereabouts.

Happy Listening   
There are a number of differences. And no, a DAC cannot eliminate anything coming out of the transport!!! The information extracted by the transport cannot be improved, any assertion otherwise demonstrates a gross lack of understanding of physics and mechanical engineering. That said, the quality of the actual transport mechanism can vary wildly. The Music Hall is an inexpensive player and uses lesser quality parts from start to finish. Also, isolation of the transport mechanism from transformer is a big culprit in degradation of the signal. Additionally, the quality of the coax port itself can have an effect. Build quality of the unit also impacts vibration. Lastly, all your connection points that are open allow digital distortion to enter the player. Toslink is always inferior to coax transmission. Quality of cable of course will impact. As you’ve experienced, the player/transport change impacted the sound. Remember, if the information from your source is comprised it will be down through the signal path by very definition. You can’t correct for what’s not there to begin with. Upgrade your transport if you hear a difference and you get to enjoy the music more. Remember, in the end it’s about the music! Best of luck.
tweak1-- so what was better, the Oppo 105 via coax, or the Marantz HDCD1 via coax?  I'm curious because I use my Oppo 105 via XLR's to a Hegel H360 Integrated to play SACD's and HDCD's and was thinking about trying the coax digital output to compare the sound quality.  Perhaps the Hegel DAC is better than the Oppo's, but not sure.
@dobnbav Of course that a DAC can improve things coming out of a transport in one simple way: memory buffer can entirely eliminate jitter and correct few other aspects of the signal. It cannot make up for missing data, but generally that's not the problem. And whether coax or optical is better once again entirely depends on the DAC. I'm fairly positive that a $500 Chord Mojo is not going to sound any different with either transport due to its immunity to jitter and/or signal quality (squareness of the incoming wave).
I believe @dobnbav is talking about much more than controlling jitter. As stated, the power supply, laser, etc. creates a sonic signature of the component. A poor design or low quality parts will pass this signature to the next component.


As long as data from CD is bit perfect the only thing that affects the sound is jitter.  Jitter, having many different forms (correlated, uncorrelated etc.), can produce many sound signatures.  D/A converter word clock's time variation (jitter) converts into many additional (very low level) frequencies on the analog side - basically a noise. Jitter can be produced by transport, by connecting cable or by the DAC itself.  DACs have ability to suppress jitter and all of them do, either by buffering combined with PLL or by Asynchronous Rate Converter (resampling data to D/A convert with new stable clock).
fred, the Oppo by a wide margin (like a torquie V8 it has a lot moe low end drive) versus a sweet turbo 4 cylinder. Keep i mind my 105 has a upgraded LPM (easy to install bought from ebay) PLUS the incoming wire rhodium IEC this makes a big difference too, but the toslink was hamstringing it.

According to Oppo tech the 105 cannot output SACD, unless your dac has I2Bus input. If not, SACD has to be played via the 105s direct outs to the amp using the variable volume control

hth.
There are quite a few variables that make comparing transports tricky. The spinning disc should be absolutely level during play. When switching transports connecting cables require settling time, maybe a day or two, before judgements regarding sound quality are made. Connecting cables are directional, if in the wrong direction the sound will suffer. Some transports may or may not handle scattered background laser light better than others.
Geoff, yes balancing is critical, especially when using your springs
@geoffkait Cables are directional. LOL. Settling time. I'm in the wrong business but of course I can't bring myself to that level of detachment from reality. 
Not the be argumentative but level is critical with or without springs. Obviously springs make it easier to balance and level. I actually distinguish between balance and level, now that you bring it up since you can balance a thing on springs yet not be level. Depends on the underlying surface which is oft not level. Furthermore, the CD level during play is oft times not (rpt not) the same level as the chassis or the tray. Obtaining level of the tray can be a little bit tricky. Finally, Out of level Condition is amplified by out of round CDs.
astelmaszek71 posts03-05-2019 10:03am@geoffkait Cables are directional. LOL. Settling time. I'm in the wrong business but of course I can't bring myself to that level of detachment from reality.

>>>>You appear to be enjoying an out of body experience right now. 🤗
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Geoff yes, yes, and yes. What naysayers fail to understand is strands of wire are pulled/drawn through a die, rough edges are bent over on a microscopic level

Many cable companies put direction arrows on their jackets, so where does this silliness come from? Ignorance, or flat ou stupidity?

elizabeth, yes, before playing any new discs I always clean them with oil free soap and RO water. I used to use various treatments, but found over time that they oxidize creating a haze that the laser cannot read through 100%. 

That said my Marantz HD CD 1 is new but the laser is very fussy, or somewhat misaligned from the factory. Never had this issue with my Oppo 105 
The beauty of the trial process.
@tweak1 What audio tweakers fail to understand that not a single of these things make a damn bit of a difference at audio frequencies. You have to start moving into microwave frequencies for any of this to have measurable effects and even then it doesn't affect anything. The entire world is running on cheap ethernet cable and even cheaper fiberoptic cable with bit perfect data making it across oceans.

As to directionality, more often than not, it has to do shielding only being connected on one end. I assure you not one cable used to wire the entire new Stratcom operations center was tested for directionality. How in the world would the cable manufactures have any idea which way the cable was originally pulled through a die considering it was spooled and respooled many times before it ever arrived at their "manufacturing" facility where they slap fancy outer jackets on them and call it hifi audio cable.
astelmaszek"What audio tweakers fail to understand that not a single of these things make a damn bit of a difference at audio frequencies."

Do you base this claim, proclamation, and pronouncement on personal, first hand experience, experiments, and analysis or are you simply repeating a religious doctrine as has become so common this site recently?
Like clean power, feeding a CD playback system with a clean disc will almost always result in improved SQ.

(Elizabeth, +1)
clearthinker +1!


astel.

apples and oranges. Data is not the same as the many nuances involved with hi-end audio reproduction

It is up to the designer to know their science. I have seen raw cable tested for directionality resistance. It matters

Although optical cable is not directional, the quality of the finishing of the cut is critical for music. Hi-end optical cables ends are highly polished using high powered microscopes

Aside from my coax, all my components are balanced, and although many tout that XR is only for long runs, I can hear the difference between a 0.5m and a 1.0 meter cable

hth
No...... You can't..... No one can, Sir.
@tweak1 directionality resistance with AC current? I assume you rapidly flip your cables...

astel, please tell me you are joking!!!!!!!!!

With a meter 
@tweak1 Clearly you missed my point. Being that current (AC) constantly flows in two directions in audio, even if such a thing as directionality existed, it would make no difference. 

I'm going to start selling the latest audio tweak. You can be the first to sign up, for only $500K I'll transplant you ears of a one year old rat terrier, so you can now hear the difference between 6inch cable and a 6.5inch cable as well as too much dust having collected on your tweeter. 

In the mean time I'll enjoy my system, all connected by Canare cable, a cable used on something like 99% of studio microphones. If it's good enough to record, it's good enough to play back.
tweak1-- so you are saying that the Oppo 105 can't output SACD via coax digital?  I think that you might be right about that...

@fred60 That is correct that the Oppo can't output SACD over coax. I don't think any player can. 
I have yet to find any transport which compares to the Philips which floats on jewels, as used in the old equipment like my Rotel RDP 980.The sound is incredible.
This unit picks a disc in 1 second.The logic is a dream, a full size pcb packed with electronics, dual psu and HQ caps.It is connected to the RDD 980, another master in my opinion.This cost me a few k years ago, well worth the buy.When i procured the 2 i stripped and re soldered both units, took a day.I replaced the Bakelite tray loader gear with a plastic gear.Can one still purchase such systems in today's price point world?


The Nakamichi Dragon CD System exhibited by Mapleshade at CES many years ago had a very unique feature. After the CD was placed on the tray and the CD tray was inserted into the transport the tray was locked in place.  Then a vacuum was created, filling the entire transport compartment. In addition, at the show, the entire 3 piece Nakamichi CD system was isolated on a sub-Hertz platform.
astel, Im talking about interconnects which transfer signal not current

hth, 
Just so there's no misunderstanding fuses in AC circuits and power cords are also directional.  All wire is directional. If you don't know what the word directionality means look it up.
@tweak1 And how do you think that "signal" gets transferred? Let me help you out: current. It never ceases to amaze me that the biggest proponents of all this voodoo have the least amount of understanding of basic principles of electronic design. Actually, it makes perfect sense.

@geoffkait I really hope the electrician in house didn't pull NM in the wrong direction.
asel,aren't all ICs driven by DC within the preamp/dac/amp? 
tweak1
... aren't all ICs driven by DC within the preamp/dac/amp?
Let's hope not. Audio signals are AC.
Astelmaszek
@geoffkait I really hope the electrician in house didn’t pull NM in the wrong direction.

>>>>My electrician uses a Push Me Pull Me. 🔛 I’m pretty sure now you aren’t gronking what we mean by the word directionality. That’s why you’re still all tangled up. We see this a lot here. No big deal.
cleed if that's true why aren't people getting the crap shocked out of them when they change ICs or speaker cables with music playing? 
@tweak1 Powered by, yes? Driven/controlled by, no? Power by DC, driven/controlled by AC in case of audio signal. Basic transistor theory.

Are you planning on ripping apart all your components, measuring resistance across each and everyone of them and switching them around if you find one with resistance higher in one direction. I'll save you some time: you won't find one like that just like you won't a piece of wire like that either. Basic physics prevents that from occurring, I don't care what you claim. 

And yes, it can all be rather easily measured with a laser pointed at each speaker driver. Just ask Devialet. I wonder why not a single cable manufacturer has ever done this to support their claims. I can tell you why. Cause they'd go bankrupt.

@geoffkait Clearly not. 
When corrected that ICs are not driven by DC within the preamp/dac/amp, but are instead AC signals:
tweak1
... if that’s true why aren’t people getting the crap shocked out of them when they change ICs or speaker cables with music playing?
Because an IC or speaker cable’s AC audio signal is very low current.
so, you're saying low current ac negates directional flow of signal? 
tweak1
so, you're saying low current ac negates directional flow of signal?
This thread is: "Differences between cd transports?" You seem to be drifting off-topic.

I was merely correcting you that audio signals in an IC or speaker cable are not "driven by DC within the preamp/dac/amp," as you had claimed.
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Look, it’s not rocket science. Take the case for two wires connected to a speaker, + and -. When the current travels toward the speaker on one wire it travels the opposite direction on the other wire. And vice versa. All you care about is the current traveling toward the speaker, so control the directionality of BOTH wires such that the preferred direction is the one toward the speaker. You don’t care about the opposite direction, the one traveling away from the speaker. It’s not audible. The direction toward the speaker is. The same logic applies to a single wire, e.g. fuse in an AC circuit. Raise your hand if you still don’t get it.
yes this should end, but if, as you said, that the ac in cables is minimal, then shouldn't it running as you said back and forth be minimal, too? 

AND, what about optic cables

Hopefully someone else with electrical knowledge in audio component and cable signal will agree with you, and put a bow on it, as it seems only the two of us are discussing this, and Im not convinced