nos dac problem?

Discussion in 'Hi-Fi and General Audio' started by kane, Feb 27, 2005.

  1. kane

    kane

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    hi all
    first post here

    got myself one of the derek shek nos dac's and am not sure if i've got a
    problem.

    when playing female vocals it sounds like i'm getting "distortion" in there
    voices.don't seem to happen on male voices or classical music.

    another anomaly:when a/b-ing between dac and cd-player,sounds that come
    out just the left speaker on cd-player come out the right speaker on the dac.

    i have triple checked the connections and they are all correct (i think :D )

    any ideas?

    kane

    p.s system used=nad c542-rotel 1062-mission 780se
     
    kane, Feb 27, 2005
    #1
  2. kane

    kane

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    i have now tried the dac on my brothers system with the same results
    system=rotel ra-01-nad c521-ma bronze b2

    so there is only two things it can be, 1 the unit is faulty or 2, it's a limitation of the dac

    any ideas...... :(

    kane
     
    kane, Feb 27, 2005
    #2
  3. kane

    BlueMax

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    Have you tried swapping the cables over?

    Since you have tried it in another system it might be a connection fault during manufacture.

    Derek Shek might give you an explanation if you email him with details.
     
    Last edited by a moderator: Feb 28, 2005
    BlueMax, Feb 28, 2005
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  4. kane

    Stuart

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    Kane,

    I've had my NOS DAC from Derek for a week or so now. I've been running it off my Rega Planet CDP for the last few days whilst I sort my PC out. Each time I've heard some distortion in the output, I've swapped back to the Rega's analogue outputs and found the distortion there as well - ie. any distortion I've heard has been from the source material and not introduced by the DAC. I've found it a little more noticeable from the NOS DAC as the Rega rounds the HF off a bit which tends to hide some of the nasties.

    If you find in back to back comparisions with your CDP that the distortion is coming from the DAC only, your best bet would be to ask Derek for assistance. I've found Derek to be really good to deal with and very interested in user feedback about his product. I'm sure he'll assist with any issues you may be experiencing.

    Haven't noticed any channel imbalance.

    Regards,

    Stuart.
     
    Stuart, Feb 28, 2005
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  5. kane

    T-bone Sanchez

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    Hmmmmmmmmmm, Id mail Derek, Ive had mine a month and now Ive made a proper psu its singing like an angel, I cant fault it. BTW Ive you had a look inside? It might be something and nothing.
     
    T-bone Sanchez, Feb 28, 2005
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  6. kane

    Aitcho

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    After you posted your message Kane I decided to check my DAC and found that my connections between DAC and amplifier were wrong, I had fitted the interconnects based on the colour coded plastic/nylon spacers that the RCA connectors pass through.

    According to Derek Shek the colour of these spacers are 'arbitrarly chosen' and are not used to determine left or right channel identification, that is where I went wrong!

    Looking at the rear of the DAC head-on the RCA socket on the extreme left is for the left channel and the RCA socket on the right is for the right channel, just ignore the colour of the spacers.

    As regards the problems you appear to be having with femail vocals (I have been in touch with Kane via email so know what CD he has particular problems with) I have tried numerous female vocal CDs without detecting any distortion.

    This morning I bought the Katie Melusa "Call Off The Search" CD that you mentioned you had particular problems with, I have played it through my system and it is perfect without any distortions.

    In addition I also used a Headsave Classic headphone amp and AKG K501 headphones and could detect no problems at all with this particular CD, I say it is a super CD.

    I would try swopping out the digital coaxial lead and see if this makes any difference or just contact Derek and see what he has to say.

    Aitcho
     
    Aitcho, Feb 28, 2005
    #6
  7. kane

    Aitcho

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    Just a follow-up to my previous message, I have just had a further email from Derek Shek and he said that all future DACs will conform to 'standard colour coding' in respect of the RCA sockets.

    This will avoid any further confusion to people like myself who tend to plug in interconnects based on colour coding without actually checking on whether the socket is left or right channel!


    Aitcho
     
    Last edited by a moderator: Feb 28, 2005
    Aitcho, Feb 28, 2005
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  8. kane

    kane

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    thanks for all your reply's guy's

    i will contact derek shek to see if he has any idea's what might be wrong

    tbh i'm thinking it might be a loose connection or maybe interference (the dac is near a
    freeview box)

    i will let you know if i get this resolved....

    cheers kane

    p.s
    bluemax, between myself and aitcho we found this to be one problem of ours
    and is now fixed :)
     
    Last edited by a moderator: Feb 28, 2005
    kane, Feb 28, 2005
    #8
  9. kane

    chris1968

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    i had an issue with evertying seeming to come from the left, complete with a lot of what i can only call grain in female vocals.

    Left imbalance was tracked down to the balance control having been inavertently moved :rolleyes: . setting it back to the middle seems to have shifted the 'grain' issue as well. though i am wondering if it is still there - think that may be all in the mind though

    That said the dac is sat on top of my unit behind and almost underneath the TV - methinks i'd best move it incase there is a distortion issue...
     
    chris1968, Mar 1, 2005
    #9
  10. kane

    Aitcho

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    Aitcho, Mar 1, 2005
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  11. kane

    T-bone Sanchez

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    BG's needs approx. 297 yrs to show their best, well not quite but do take time to shine. The dirk shek dac needs a better psu then whats supplied, then it starts sounding far better.
     
    T-bone Sanchez, Mar 2, 2005
    #11
  12. kane

    michaelab desafinado

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    I built a new PSU for my NOS DAC using this. Little regulator board + small toroidal only 53 Euros. Stuck it in a case with an IEC socket and leadout (power) wire and that was it. Made quite a significant improvement IMO.

    Michael.
     
    michaelab, Mar 2, 2005
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  13. kane

    Aitcho

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    I am not into DIY PSUs, I have enough problems mending fuses!

    There is a PSU for the Derek Shek DAC which is nearing completion, he is just awaiting the cases that the power supply internals will fit into.

    He has sent me a couple of images of the transformer and PCB which can be seen here:-

    http://img180.exs.cx/my.php?loc=img180&image=26sj.jpg

    http://img180.exs.cx/my.php?loc=img180&image=17iy.jpg

    It is nice to know that there is more improvement to be had from the DAC with an upgraded power supply.

    Aitcho
     
    Aitcho, Mar 2, 2005
    #13
  14. kane

    BlueMax

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    Location:
    South Coast of UK
    5 Amp Power Supply
    SMPS 60W 12V output
    Manufacturer: Stontronics
    A high power, fixed output, switch mode power supply that meet all safety and EMI regulations – UL, CSA, TUV, BS etc. Input is via a 3-pin IEC C-14 socket, with output via a 3.1mm power plug attached to 1.8m of flying lead. All are housed in a tough moulded plastic case with a fully regulated and protected output.
    [​IMG]
    Order code 85-1844 at www.rapidelectronics.com UKP30.43 incl VAT.
    Stontronics might have a stockist in other countires. They also make 80 and 130 Watt models.
    http://www.stontronics.co.uk/productlist.cfm?lproducttypeid=1

    Other models worth looking into are these Stabilised Power Supplies:
    HP145. Stabilised 13.8V, 5A. EUR 40,28
    HP147. Stabilised 13.8V, 7A. EUR 47,51
    ZETAGI S.p.A., Via Ozanam, 29 - Concorezzo (MI) - Tel. (+39) 039.60.49.346 - Fax (+39) 039.60.41.465
    http://www.zgitaly.it/power E-Mail: [email protected]

    Outputs 13.8V but popular with various T-Amp designs that are also 12V nominal as with NOS-DAC.
    Check with the manufacturer of your particular NOS-DAC to make sure that 13.8V do not exceed voltage tolerances.
     
    BlueMax, Mar 2, 2005
    #14
  15. kane

    T-bone Sanchez

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    I bought a chassis with the regs already soldered on, the only difference with mine is that Ive quite a few large caps to smoooooooth that juice, not sure if they are needed. Its made quite a significant improvement to mine, Im pretty pleased.

    Is that harryo by any chance??
     
    T-bone Sanchez, Mar 2, 2005
    #15
  16. kane

    Class A

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    Class A, Mar 2, 2005
    #16
  17. kane

    BlueMax

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    Location:
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    That is by eBay seller Panda_99 (MHDT15214 Lab).
    “TDA1543 Non-OS DAC 230/115V -- V2.0 Digital Password†from Taiwan.
    Uses TDA1543, CS8412, TL431 and LM317
    [​IMG]
    http://www.geocities.com/mhdt15214/Main_v2.0.htm
    http://www.geocities.com/mhdt15214/Parts.htm

    Good quality components and well made but cheaper at about £70 (if you buy direct).
    I haven't used one but have heard good reports.
    Though some people prefer a seperate PSU.
     
    Last edited by a moderator: Mar 2, 2005
    BlueMax, Mar 2, 2005
    #17
  18. kane

    Class A

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    Bluemax
    Thanks for that, where can I buy one of these direct for £70?. I m thinking of linking up one of these dac to my Sony SCD-1 for redbook replay.
    cheers
     
    Class A, Mar 2, 2005
    #18
  19. kane

    Aitcho

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    Yes it is. :)



    Aitcho
     
    Aitcho, Mar 2, 2005
    #19
  20. kane

    Aitcho

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    Panda_99 (mhdtlab) has recently introduced another DAC called "Digital Renaissance" (TDA1543V3) which has a different circuit layout compared to his "Digital Password" DAC.

    There is a valve incorporated into his latest design, you can view images here:-

    http://photobucket.com/albums/v309/mhdtlab/TDA1543V30/

    Aitcho
     
    Aitcho, Mar 2, 2005
    #20
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