SONY CDP-101 : CX20017 dac improvement

Discussion in 'Digital Sources' started by cizeta, Jan 18, 2018.

  1. FileFixer

    FileFixer Well-Known Member

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    545
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    Zagreb/Croatia
    Thanks above for all your support to me. Usualy life in this country is not to much easy if you need to buy some of special electronic tools. e.g. Any price for osciloscope is more then doubled but payroll for our work is not to much high. We can to buy that equipment from all EU countries but when we buy this equipment we have high taxes. As I say before, I have all these measurement equipment on my workplace but I need to move all my audio equipment to the workplace then work on it and after that I need to move all that things back to my home to hear is that changes good or not. So, my only choice is to inspect precision on my sound card and software what I use on workplace and see is it ok for that or not and move this soundcard back to my home and use it with best what I can. In the near future I`m thinking to buy some simple 2ch osciloscope... For any analyze on audio files I use ARTA software. I`m looking on some HANTEK or Velleman WFS210 or any similar DSO... What you can to reccomend to me for that purpose and with low price?
    @cizeta Thanks for software, I will try it. ;)
     
    Last edited: Jan 20, 2018

     

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  2. restorer-john

    restorer-john Addicted Member

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    Maybe pick up a cheap 20/50MHz dual channel old-skool CRO from ebay- they practically give them away?

    I still have mine that I bought as a schoolboy 35+ years ago. It cost me around $600 back then. It's worth nothing now, but still works perfectly. I still love it.
     
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  3. cizeta

    cizeta Member

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    The digital oscilloscopes are comfortable, but they do everything by themselves ... I feel excluded from the game!
    The oscilloscope in my avatar is analog .. A DSO would have hooked the eye of the RF laser in the middle of the screen and not on the left ...
     
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  4. restorer-john

    restorer-john Addicted Member

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    Honestly, I agree. I love my 30 year old Trio 60MHz analogue scope- it's never let me down. It even fell off my bench once. Bent a BNC connector and cracked the front panel corner, but no other damage. That was 20 years ago and it's still going.
     
  5. cizeta

    cizeta Member

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    Put aside, well covered, there is my old Tek 475A that sometimes I light on to smell the good smell coming out of the rear fan and that makes me go back in time ....Even that is still fully functional ...
     
  6. FileFixer

    FileFixer Well-Known Member

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    Thanks for advice... I will to find something.
     

     

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  7. FileFixer

    FileFixer Well-Known Member

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    Today I was checked how Technics SL-PS770D looks on same Soundcard Osciloscope on what I inspect Pioneer DV-300 and to compare and see is it Pioneer DV-300 plot real or software get own not to much real results. compassion looks that this Soft Osciloscope do good job but also seems that Pioneer DV-300 have outstanding sound on analog outputs in opposite to Technics SL-PS770D...

    [​IMG]

    [​IMG]
     
  8. FileFixer

    FileFixer Well-Known Member

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    This is difference in Frequency Response between Pioneer DV-300 and technics SL-PS770D... It seems that Technics lacks in opposite to Pioneer in high frequency range...

    Frequency Response comparision...
    [​IMG]

    This is some better measurements then before with soundcard. More detailed... I see somethin on *.ini file inside program that can be tuned for better measurements. ;)

    Pioneer DV-300...
    [​IMG]

    Technics SL-PS770D...
    [​IMG]
     
  9. restorer-john

    restorer-john Addicted Member

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    I would say the Technics square wave is much better looking, considering the PC scope is also heavily bandwidth limited- essentially has an inbuilt LPF at Fs/2.

    What is you sample rate on the soundcard? 192?
     
  10. FileFixer

    FileFixer Well-Known Member

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    Soundcard is on 192kHz. Into the *.ini file on Soundscope I do changes and limit on 44.1/16. Soundcard is running on kX drivers. I am also do same tests with Signal Analyzer...

    Pioneer DV-300
    [​IMG]

    Technics SL-PS770D
    [​IMG]
     
  11. FileFixer

    FileFixer Well-Known Member

    Messages:
    545
    Location:
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    I`m thinking that is not problem on that signals but problem persist somewhere in analog section into Technics player. For that reason when I look on Frequency Response plot and listen these players, on my ear Pioneer have better sound, something like it have better dynamics and sound lively then Technics.
    I`m look inside to see and it seems that Technics do some changes on analog section... RED color shows what is difference insted on schematics... Technics change LM833 with M5238 Op-amp into the Difference amp and LM833 with RC4580 in its sum output then change capacitors on 150p with resistors at 6.1 kOhm. This section (IC891) does not do anything with Low-Pass filter and also does not have any purpose in signal path. It is an excess that does not serve anything except for more degradation in sound, output is same as on previous RC4580 stage with 6.2V p-p.

    [​IMG]
     
    Last edited: Jan 28, 2018

     

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  12. FileFixer

    FileFixer Well-Known Member

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    I found one nice progam for software osciloscope, also work with hardware scopes but it have options for scan signal from sound card. What I see from test it works very smooth and also have huge options. Name of this program is Virtins Multi Instrument. It is not free but trial version work 30 days and it have full options for that time... This is results on Technics SL-PS770D...

    [​IMG]
     
  13. Salar

    Salar Member

    Messages:
    66
    Maybe this is the place for asking my question:
    I would like to add digital output using a DIT4092 from Burr Brown.
    Did this already some years ago on a 2nd. generation Sony-based Nakamichi.

    All signals I need seem to be present in the CDP-101: Data / Bit Clock / L-R clock.
    But there seems to be no crystal on board of the CDP-101 to provide the standard base frequency of 4.2336mHz.
    Four times of this frequency are needed to clock the DIT4092 which is easy by using flip-flops.
    Another way could be using a 16.9344mHz crystal, directly driving the digital transmitter
    and having the frequency divided to 4 in order to clock the CDP-101.

    In later players the clock frequencies mentioned above were produced directly by the crystals on board,
    but they seem to miss in the CDP-101. Only one 4mHz crystal in the datasheet mentioned

    BTW I was very, very lucky with this player: I bought it new in 2014. It was stored in the cellar of a HiFi-Shop for 31 years.
    Picked it up personally , could not believe it; The box covered with dust but untouched.
    Even a red velvet cloth for cleaning the CD and a catalogue of the first CD-releases were in the box
     
  14. onwardjames

    onwardjames Hoardimus Maximus Subscriber

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    This is results on Technics SL-PS770D...


    I used to have two of those cd players, obtained from my former workplace (old radio station). I always liked the softer highs on this cd player. I still have an SL-PS700 Technics, which I consider a fine CD player.

    Fascinating thread.
     
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  15. cpt_paranoia

    cpt_paranoia Active Member

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    201
    I don't like the chunks taken out of the rise/fall excursions. At least the Pioneer is symmetric...

    The ringing could either player or sound card...
     
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  16. restorer-john

    restorer-john Addicted Member

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    Best to start a thread for this.

    BTW, there's a 35.022MHz Xtal on the CX20017 and an 8.6MHz Xtal on the CX7934 which is divided down to approx 22uS to run the L/R ch switching. Not sure what you mean about missing crystals- there's a least 4 in the CDP-101.
     

     

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  17. mbates14

    mbates14 Well-Known Member

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    Here is another related but unrelated thing. I have a Pioneer P-D70 which uses the same DAC setup as the sony CDP-101, However one of the 2 filters is bad but its epoxy sealed and proprietary so I cant do anything about it except make a new one.

    Does anyone have the filter specs required for this type of DAC setup? Also is it possible to wire in a different type of DAC? or is the signalling proprietary? just curious.
     
  18. Salar

    Salar Member

    Messages:
    66
    Yes, but none of the crystals seems to have a frequency which is integral to 16.9344mHz: 4.2336mHz or 8.4672.
    As far as I understood, these frequencies are basics for CD-playback but I cannot find the math right now.
    Besides the CDP-101 you will find the frequencies mentioned above in any CD-Player from the second generation on,
    ranging from 4.2336 in early players up to 67.7376 in modern players, which is 16x.

    http://www.tentlabs.com/InfoSupport/page21/page21.html

    So having 4.2336 already there would make adding a digital output using a DIT4096, which needs the 4x multiple of 4.2336 = 16.9344 fairly easy.


    Also 35.022 is not integral to 16.9344, I assume the CDP-101 uses PLL to achieve 4.2336 somewhere in the circuitry?
     
  19. FileFixer

    FileFixer Well-Known Member

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  20. onwardjames

    onwardjames Hoardimus Maximus Subscriber

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