Question CD Player Transport

Discussion in 'Hi-Fi Stereo Systems & Separates' started by Hawklord, Jul 12, 2018.

  1. Hawklord

    Hawklord
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    I have recently purchased an external DAC (Roksan K3) and would like to purchase a decent transport with a digital out to feed the DAC.

    Will any cheap CD player suffice or would it be worthwhile spending more for a player with a good transport.

    The DAC is being used with a Yamaha AS-1100 and KEF R500 speakers.

    Any pointers to a player worthy of complimenting this set up would be appreciated.
     
  2. dannnielll

    dannnielll
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    Not only will a CD player do, but the cheapest DVD player having a display, a remote control and a coaxial digital audio out ( orange insert RCA) will suffice... you need the display to figure which track and to select tracks
    It will be the quality of the DAC in the Rocksan which determines the audio quality.
     
  3. Don Dadda

    Don Dadda
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    If you have a blu ray player already, you can use that
     
  4. Darious

    Darious
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    I would rather not buy another DAC (built into a CD player) and would instead prefer to pair your new Roksan DAC with some decent CD transport, i.e. the one from Cambridge Audio - CXC (£300 brand new, probably cheapest CD transport in the world). It's not best (i.e. Cyrus CD transport would be perfect), but does the job fine enough.
     
  5. dannnielll

    dannnielll
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    .. but Darius, that is approximately 250 quid more expensive than a DVD player which will do exactly the same function. Granted the two DACs in the dvd player (one for audio, one for video ) will not be the same standard as the Rocksan model, but then they are not being used. A transport is a transport, it reads the data from the disc, error corrects if necessary and then sends it out . The transport electronics, selects the tracks and keeps the lasers in the correct location. Speed fluctuations, vibration on the platform none of these things matter provided the data stream is uninterrupted. The data is serial so unless the jitter is so bad as to miss an entire bit, it does not matter either. One would assume that the expensive DAC in the Rocksan will have a de jittering reclocking circuit.
     
  6. muljao

    muljao
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    Sound quality wise as said above any player digitally fed to the DAC should sound the same.

    If I were in your position I'd likely try to buy a well loved second hand cd player or something like an entry level marantz or similar cd player (maybe a yamaha would work with amp remote keeping that part easy) simply because of the function setup, the display etc, but more importantly cd players are generally quieter in operation than dvd and Blu-ray players.
     
  7. Darious

    Darious
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    OK Hawk Lord, any cheap CD/DVD player will do :D

    ..but if you find after a while, that something actually could be missing, check out that CXC.
     
  8. Hawklord

    Hawklord
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    I have bought the cxc.
     
  9. dannnielll

    dannnielll
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    Enjoy!!
     
  10. mark6226

    mark6226
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    Not all CD transports are equal .The Cyrus cdt or cdt xt will certain be better than a dvd player or cheap CD player. Putting low quality sources into an expensive system is really not a good idea. You won't maximise your system potential if you do that
     
  11. dannnielll

    dannnielll
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    Define better in this context?... If the transport sends out the full data stream, with or without jitter and gives the user the ability to change tracks ,what more can it do?.
     
  12. Welwynnick

    Welwynnick
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    This subject has come up several times. Everyone thinks transports sound the same because they produce ones and zeros.

    This assumes that the output of a transport is just digital data, whereas it is in fact digital audio, which is different. Digital audio consists of digital data and digital clock.

    The clock is actually an analogue signal, and this varies from one transport to another. The degradation or variation is called jitter, and this probably accounts for most of the differences between transports (and their connections).

    Jitter is very unlikely to cause bit loss - that would be very bad indeed, far worse than what is audible. The mechanism for audio degradation from jitter is that it applies phase modulation to the output of the DAC, and increases noise and distortion, especially at high frequencies.

    Jitter is demonstrably audible, and is usually worst with complex video players like DVD and Blu-ray players. Dedicated CD players and especially transports are usually best.

    Nick
     
    Last edited: Jul 27, 2018
  13. andy1249

    andy1249
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    Summarised here ....
    Note the link halfway down , to a paper on how various players performed with the same material.
    Conclusions , Bad PSU and inaccurate servos definitely altered the output stream in an audible way , jitter was dismissed as irrelevant , as it usually is.

    Q. How much impact can a CD transport have on sound quality? |

    Direct link to the paper
    http://www.prismsound.com/m_r_downloads/cdinvest.pdf

    Summing up , CD transports "should" be all identical if the basics are followed , but never underestimate the lengths a manufacturer will go to in order to maximise profit.
    There are some very nasty transports out there that don't do what they "should".
     
  14. gibbsy

    gibbsy
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    Good points. Interesting article.
     
  15. dannnielll

    dannnielll
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    The data stream from the transport is not analogue. It is a digital data stream in which the clock is embedded along with the data. It goes under a variety of names such as differential Manchester coding the SPDIF and any number of other serial data streams use it. Even if there is jitter in the production of the data stream, that can be filtered out by proper electronics.

    The case you have repeatedly been making is that there is something special about audio digital data..and there is not. It is much more robust and less sensitive than financial information sent ,using the same technology between banks.
    There is a case to be made that the sampled voltage output from a DAC must occur at a fixed rate with little or no difference in that rate, (certainly over the short term.) That is the only place where the jitter could matter. How the master clock is derived, extracted and then rephrased from the SPDIF combined clock and data, jittery as it may be, and how the samples are then processed is down to the design of the DAC and it's ancillary circuits.
     
  16. Welwynnick

    Welwynnick
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    The audio data is digital.

    The audio clock is analogue, and it's just as vulnerable as any other analogue signal.

    It's easy to believe all the marketing hype about DACs and processors that can re-clock digital audio and get rid of the jitter. It's possible in theory, but practice is different. In my experience it just doesn't work, even with quite expensive equipment from reputable manufacturers who know what they're doing.

    I haven't heard the latest and greatest DACs with effective ASRCs like the Benchmark DAC3 or NAD M51, which really do measure astoundingly well, and in their case I wouldn't claim that I could hear the difference between different sources with them, but for mainstream equipment that uses imperfectly-implemented PLLs, I think the source does matter.

    Nick
     
    Last edited: Jul 28, 2018

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