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Cable effect

Discussion in 'audio' started by Nic P, Nov 21, 2010.

  1. Nic P

    Nic P pfm Member

    I replaced a Naim 250 with a Tom Evans Linear A. I used a a cheapo cable to connect to the Linear A because I needed the XLR connection on my Nordost Quatrofil to demo the 250 when selling it. After I sold the 250 a friend reterminated the Nordost and I put it with the Linear A and was very pleased with the sound. I hate A/B comparisons so didn't do any (let alone a double blind ... ). I didn't care whether I could prove to myself that it was better. Some days later I played the new Elton John / Leon Russell "The Union". I always had difficulty being sure whether Elton or Leon was singing (I think I would have got it right most of the time). With the Nordost in I would get it right 100% of the time, it is so clear that they are different voices. I was interested that my subjective impression was so clearly vindicated (to me at least).

    Nic P
     
  2. dave

    dave Plywood King

    Most likely the result of a mind-altering substance smeared on whatever you reterminated with by the manufacturer because as Everyone™ knows, page 62 in our Radio Handbook says this can't be so.

    Repeat after me sixty-two times...only phono cartridges, TTs and speakers have a "sound" until The Experts allow otherwise.
     
  3. Nic P

    Nic P pfm Member

    only phono cartridges, TTs and speakers have a "sound"
    only phono cartridges, TTs and speakers have a "sound"
    only phono cartridges, TTs and speakers have a "sound"
    only phono cartridges, TTs and speakers have a "sound"
    .
    .
    .
    only phono cartridges, TTs and speakers have a "sound"
     
  4. avole

    avole The wise never post on Internet forums

    You remind me strangely of Don Quixote, Nic P, except slightly more obsessed.

    Time to move on to newer pastures perhaps - why vinyl is infinitely superior even when it isn't played on anything Naim, for example.

    Anyhow, good luck with your quest.
     
  5. dave

    dave Plywood King

    Those periods aren't proof of sixty two times young man (and we need proof, no, we must have proof, we must, we must, we must have proof or there's nothing that separates us from the animals...)
     
  6. whatsnext

    whatsnext Naimless

    You are wired
    But clearly vindicated is wierd
     
  7. vln

    vln Shuns mooks. And MQA.

    Now now, dave, don't get all sarky...

    Though being a bit of cable skeptic myself these days, I can certainly see that you can/could make cables with some crazy electrical properties which in turn may have some influence on the sound. The effects that solid core cables have in some systems seem to be an indication for this. I just think that with most 'standard' cables the difference is very small or even non-existant. Of course, all cable manufacturers will claim that *their* cables are far from standard...

    I have currently a pair of OCOS cables at home, for two weeks of auditioning, and their technical background is quite interesting:

    http://www.dynaudio.com/eng/pdf/DYN_Ocos_TechnGrundl_INT.pdf

    (If some more technical minded PFMers have comments on this, I would be happy to hear them!)

    In the first couple of hours with the OCOS I was distinctly underwhelmed (as I expected to be), but now I *think* I can hear some improvements: better dynamics, more focus, everything somehow sounds cleaner. Whether this is worth 700EUR to me is another question, the improvement the cable brings is certainly very small compared to the improvement that the room correction system of my amp brings.

    There was a thread about OCOS a while ago, I will post my findings there, once I come to some conclusions.


    Samuel.
     
  8. Nic P

    Nic P pfm Member

    Obsessed - irregular verb:

    I alone know the truth,

    You are deaf,

    He is obsessed,

    We don't give a damn what you think.



    Nic P
     
  9. sq225917

    sq225917 Bit of this, bit of that

    The OCOS contain a filter, so yes they have a 'sound', well a filter effect more accurately.

    Some other speakers also act as filters due to their geometry but all any of them can do is roll off frequencies and skew the response.
     
  10. vln

    vln Shuns mooks. And MQA.

    Can you be a bit more precise? What exactly are they filtering?

    I agree that a cable can certainly not add anything to the signal, but it may take things away, thus making every cable a filter to some degree.

    However, assuming for a moment that the information Dynaudio provides is accurate, what sets the OCOS apart is that the impedance is lower / less frequency dependant than in other speaker cables, which should make them less of a filter in that respect.

    I understand early Dynaudio speakers had a special OCOS socket to plug the cable in directly, using some special connector.

    These days, it's just a cable (a rather thin and unassuming looking one at that).
     
  11. avole

    avole The wise never post on Internet forums

    Have to agree with vin. The reason I've bought OCOS (waiting for delivery) is they do nothing to the signal. From reading the tech paper I would have thought filtering is the last of Dynaudio's objectives.
     
  12. sq225917

    sq225917 Bit of this, bit of that

    Like any cable, but more so, The OCOS acts as a filter due to its combination of fixed cable impedance and added parallel filter network. .33uf cap and 8ohm resistor or thereabouts if memory servers me right. This basically acts as an RF filter.

    The impedance effects of the cable itself will be benign, but not the add on filter units they are meant to be used with. Whether the effect is actually audible is another question altogether.

    I wasn't aware they had removed the filter, i bow to you experience in that respect.
     
  13. avole

    avole The wise never post on Internet forums

    What filter units are these? The tech paper and the web site don't mention them. I'm a bit concerned now, having splashed out on them because they are meant to be the most neutral speaker cables around.
     
  14. sq225917

    sq225917 Bit of this, bit of that

  15. avole

    avole The wise never post on Internet forums

    The Dynaudio site doesn't mention them, so I assume they've been discontinued. That review was 2007, after all.
     
  16. stevec67

    stevec67 pfm Member

    The capacitor would be tricky but the presence of a resistor would be easy to detect with a multimeter. A conventional cable after all has a DC resistance around zero, so 8R will be easy to spot.
     
  17. rontoolsie

    rontoolsie pfm Member

    I used to use a tripled up (three in parallel) run of OCOS in the days when I had the Exposure XVI monoblocks. At the speaker end there was the option of using some impedence matching terminators (either two reds and one black, or two blacks and one red)- I tried both options. I found that the triple OCOS was slightly better than the Exposure speaker cable-which looked much like rebranded NACA4 but not quite as good as the NACA5, which at the time was maybe one tenth of the tripled up OCOS cost.
     
  18. sq225917

    sq225917 Bit of this, bit of that

    Yes, let's of progress been made in cost cutting since 2007 ;-)
     
  19. Robert

    Robert Tapehead

    All cables are filters but luckily the cable parameters of most available combined with the source and load impedance pushes the filter waaaaay out of audibility - nowhere near the audio band. That's one reason why most cables sound the same.

    Some do differ though.

    Cables with high capacitance can often stand out as impressive because they can give measurable and audible rising response at HF. Not always a bad thing - can help valve amps for example by countering inductance in the output transformers.
    Usually a bad thing for SS amps though and if high enough the capacitance will cause oscillation, and possible failure. Effectively, the amplifier 'sees' a load approaching a short circuit at high frequencies with high capacitance cables.

    Cables with high inductance can subtly roll off the top end. Again how much and where depends on what you have at each end.

    Loop resistance alters the power transfer characteristic and as resistance rises, the loudspeaker response is pulled into progressively closer resemblance to the impedance curve (hint- they are usually far from flat). DNM does this and usually sounds quite different as a result - nothing to do with skin effect or single strand theory. Put a 1-2 ohm wirewound resistor in series with some NACA5 and it'll sound like DNM (L & C are similar).

    The vast majority of cables used in the vast majority of situations will not manipulate the signal to a degree that is audible.... to humans at least ;)
     
  20. vln

    vln Shuns mooks. And MQA.


    Hi Rob,


    thx for that, much appreciated.

    So what is the influence of loudspeaker cable impedance on the signal - if there is any? In the information Dynaudio provide on the OCOS cable, they mention that impedance rises to very high levels at audio frequencies, rising to 1,248 ohms at 100 Hz (page 4), but with the OCOS cable this supposedly doesn't happen (page 9).

    I don't assume that this effect being disputed, i.e. the physics behind this is sound, but I guess the question is whether this effect is audible given that the rise in impedance takes place well in the range of human hearing.

    Any comments?


    Cheers,
    Samuel.


    PS:
    The guys who produce the OCOS cable certainly look like they shun mooks (if you catch my drift):

    http://www.hubersuhner.ch/co-ch/mozilla/ch-index
     

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