Difference in sound between copper and silver digital cables?

@david_ten - Ooooops sorry about that….

@williewonka Steve: within the parameters of (the "experiment" / components / systems) you tested them, correct? Thanks.

Yes - I was testing with digital audio files up to and including 24/192. They connected a Schiit Bifrost DAC and a Musical Fidelity V-Link192 USB-S/PDIF Converter and an Apple PC as the source of the digital files via USB.

The amp was a NAIM 5i Mk II and the speakers are the Gershman Acoustics Sonogram model

I could not discern any degradation in audio quality at those sample rates, higher sample rates may have issues, but I am unable to test ot those rates.

I did drop down to the copper Harmony RCA and there was also no degradation, but I the silver plating on the copper harmony may wear off after 30 insertions, so I do not use them for anything.

My Silver Harmony RCA’s had been inserted around 40 times to that point without wearing to the copper underneath the plating. But this very much depends on the quality of the socket they are plugged into.

For all analogue cables I only use Harmony Absolute RCA’s

Hope that helps

@williewonka   Steve: YES.   Very much so. Thank you!

... could it be possible that the impedance of the RCA only has to be greater than 50,75,101 ohms?

@williewonka

Hi Steve,

Thanks for providing the additional background. But no, for accurate minimally distorted transmission of digital waveforms, the "characteristic impedance" of a digital cable, the output impedance of the component providing the digital signal, and the input impedance of the component receiving the signal, should all be very close to being exactly the same.

In saying that, I should emphasize two things. First, this has nothing to due with accurate conveyance of the digital bits, which figures to be perfect in any half-way reasonable interconnection. Second, the distortion of the waveform that is received by the destination component does not by any means have any **direct** relation to distortion that may result in the sound that is eventually heard, as it might in the case of transmission of analog signals. But what may happen is that the frequency components corresponding to that distortion of the digital waveform, which will be well into the RF region, probably at several tens of MHz or even more, may find their way past the receiving circuit (via grounds, power supplies, stray capacitances, etc.) and contribute to timing jitter at the point of D/A conversion, or to intermodulation or AM demodulation or other such effects at analog circuit points further downstream. All of this being very much dependent in unpredictable ways on the particular components, on the normally unspecified "risetimes" and "falltimes" of the signal provided by the source component (i.e., the amount of time required for the signal to transition between its two voltage states), and on the length and several other characteristics of the particular cable.

Ground loop effects between interconnected digital components can also be cable-sensitive, btw, potentially resulting in low-level high frequency noise being injected into the DAC or other receiving component, with consequences similar to those I’ve described above.

All of this is completely different than the potential effects of cables conveying analog audio signals, due to the vastly higher frequency components of digital audio signals. In the latter case bit rates are already well into the RF region (roughly between 1.5 and 10 MHz or so, depending on whether it is redbook data, 24/192 data, etc.), where imprecise impedance matching can degrade waveform quality due to signal reflection effects. But the frequency content of the risetimes and falltimes of all of those signals are at even much higher frequencies, at several tens of MHz even for redbook data as I said.

One thing that follows from all of this, IMO, is that any similarity that may be observed between the sonic effects of various metals and various geometries as used in analog audio cables vs. as used in digital audio cables is entirely coincidental.

And, finally, I would approach with a great deal of skepticism any claims that a specific wire type can simultaneously be optimal for 50 ohm, 75 ohm, and 110 ohm digital applications. And I feel pretty certain that nearly all other experienced digital circuit designers would agree with me. While it may not make any difference in some systems, or it might even make a difference in some systems that seems to be subjectively preferable, why do what amounts to introducing a known design flaw into the system?

Best regards,
-- Al

I have experienced very large differences between digital cables and I've tried many. I've paid less attention to materials/metallurgy when it comes to digital cables more to overall design. I've had silver, Kimber AGDL,  mixed materials, Cerious Technologies, and copper, Nirvana, Acrolink, Jorma.


As an overall comment over the years I've gravitated from all or mostly silver cables to all copper now. I prize warmth and musicality over excessive detail. The Jorma digital cable I use, hyper-pure copper, gives me a warm rich organic sound with plenty of detail.


My advice is to experiment buy some used digital cables and keep at it til you find one you love.