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Re: [regsaudioforum] Re: cables and true believers

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  • Uli Brueggemann
    Some experiences and thoughts: 1. a long time ago, in my feeling 25 years, we have used a PC in a machine tool application. The PC has been built into the
    Message 1 of 6 , Jul 1, 2009
      Some experiences and thoughts:

      1. a long time ago, in my feeling 25 years, we have used a PC in a machine tool application. The PC has been built into the electrical cabinet of the machine, an environment with a lot of electrical noise. The RGB monitor has been built into the operator console with a distance of 20 m cable length.
      As you can imagine the screen display did not look very nice, indeed it was unreadable.
      Then we have found another cable, specially made for such long distances, and the display was ok.
      Result: cables make differences, especially in high frequency applications like this example

      2. At this time I also have built some CNC control with microprocessors and I had to learn that it is necessary to apply the proper terminations at the backplane to get the system running. I experienced that independant of the type of the backplane, wire-wrap or PCB, the termination must be done correctly to avoid signal reflections.
      Result: the termination has a big influence, especially in high frequency applications

      There is a lot of theory and application guidelines how to do a proper termination

      3. Today we transfer digital information but it seems that people don't take care about the termination. They just exchange the cables and discuss the sound differences. The cables typically have connectors which do not follow the requirements about impedance and of course nobody knows about the real specs of sender and receiver in his equipment.
      Is there anybody out there who measures the signal quality with a scope? And who adjusts the cable and termination parameters in a way that the digital signal is transported optimally?
      Tuning the digital data transfer by ears seems to be impossible for me.

      Please note, this is a discussion about high frequencies which accompany a digital data transfer, square wave signals contain high frequencies. And the influence of noise, ground loop currents and RF sensitivity is even not discussed here.

      So IMHO changing cables is like a lottery. But mainly the cable sellers win.

      Uli



      On Wed, Jul 1, 2009 at 4:05 AM, sunilm_k2 <sunilm_k2@...> wrote:


      Well ... GHz computers work because by operating in the binary world, they are somewhat immune to some signal imperfections that would be audible in the analog world. When the correct communication of timing is important for example, e.g. when conveying so called 'digital audio', then apparently cables can make a difference.

      -- Sunil



      --- In regsaudioforum@yahoogroups.com, "Robert Greene" <regonaudio@...> wrote:
      >
      >
      >
      > PS How do you think your gigaHz computer works without being full of 6 nines copper and so on?
      >


    • ymm
      Or any unshakable beliefs and convictions of whatever stripe or kind.   best Yip ... From: Robert Greene Subject: [regsaudioforum] cables
      Message 2 of 6 , Jul 1, 2009
        Or any unshakable beliefs and convictions of whatever stripe or kind.
         
        best Yip

        --- On Wed, 1/7/09, Robert Greene <regonaudio@...> wrote:

        From: Robert Greene <regonaudio@...>
        Subject: [regsaudioforum] cables and true believers
        To: regsaudioforum@yahoogroups.com
        Date: Wednesday, 1 July, 2009, 8:16 AM


        I know it is a mistake to argue with people about religion,
        and the cable business is religion indeed.
        But I would be curious if ANYONE can produce evidence
        that there is any audible cable effect whatever
        on line level or amp level speakers that is not
        either a matter of lumped parameters(LRC) and related
        frequency and phase matters
        and/or
        RF filtering.
        I have never seen ANY evidence that anything else counts.

        Keep in mind that
        1 small frequency response shifts are highly audible but are usually observed as something other than tonal matters(eg increased clarity)

        2 all the wonderful measurements of audio performance that audio electronics show are obtained using perfectly ordinary wires and power cords.

        3 no one EVER submits anything like scientific evidence of anything except the lumped parameters and RF effects.

        4 Both lumped parameters and RF matters are arrangeable cheaply.

        Speaker cables and interconnects do of course sound different. They can knock frequency response around in one way and another. But I have never ssen ANY real evidence that they do anything else.

        Of course there are all kinds of effects that arise at very high frequencies and over very long lengths and so on. But in the audio world...

        one still has to wonder how if wires count so much, that those same people can be crazy about Golden Age recordings-- which were all done with ordinary wire, there being nothing else.

        It is as if the signal damage that must have occurred decades ago
        (because of the ordinary wires) somehow went away as the records sat on the shelf or something.

        Anyone care to try to explain that?

        Lots of things make small changes in sound, including cables--they change frqeuency response. But where is any evidence that they change anything else(except for Rf filtering--which is dirt cheap).

        REG

        PS How do you think your gigaHz computer works without being full of 6 nines copper and so on?



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      • Jose Antonio Almagro Pastor
        ... Obviously you didn t ask B&K for a quotation ;-) Please forgive my joke, of course cables can t do miracles and if it s audible, it s measurable. And when
        Message 3 of 6 , Jul 1, 2009


          2 all the wonderful measurements of audio performance that audio electronics show are obtained using perfectly ordinary wires and power cords.







              Obviously you didn't ask B&K for a quotation ;-)

              Please forgive my joke,  of course cables can't do miracles and if it's audible, it's measurable. And when it's audible is because of lacks or bad impedance matching.

              Best regards.

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