Thanks, guys. Regarding twisting the cable right-handed, I suspect that the person who was quoted was vaguely thinking of what is known as the
"right-hand rule", which describes the relation between the direction of the magnetic field surrounding a conductor and the direction of the current flowing in the conductor which produces that field. But I agree with Salectric and Bill, and I don't see that as having any relevance to a twisted pair interconnect. And IMO proving otherwise would require, as a minimum, comparing two cables that are identical except for which hand was used to twist them, under equal conditions of system warmup, AC line voltage and noise conditions, and cable breakin. And preferably when connecting a variety of components. I doubt anyone has done that.
Regarding shielding, there are of course many variables that can affect its consequences, involving the designs of the components that are being connected as well as the characteristics of the cable. So I would second the comment by Charles in his most recent post, to the effect that listening in a given system is the only way to determine which is preferable. My instinctive guess, though, would be that more often than not a shielded cable will tend to provide results that are a bit more accurate (which is not to say that those results would necessarily be subjectively preferable).
Regarding the frequently claimed tendency of unshielded cables to sound more open, I think that is likely to often be the case. Which, however, may or may not mean that the cable is behaving in a more accurate manner. If the component driving the cable has a high output impedance, and especially if the length of the cable is also long, the reduction in cable capacitance that probably results from eliminating the shield may improve high frequency extension and thereby result in a more open (and accurate) sound. But in many cases increased pickup of RFI or other high frequency noise, or possible increases in ground loop-related high frequency noise (see the next paragraph, keeping in mind that ground loop issues can result in high frequency noise as well as low frequency hum), could create the subjective impression of a more open sound, while at the same time being less true to the signal source. I've seen it said a number of times over the years that low level high frequency noise can contribute to a subjective perception of increased ambience, which makes sense to me. Also, low level noise at frequencies that are too high to hear directly can conceivably have similar consequences, by intermodulating with signal in the component circuitry and thereby affecting audible frequencies.
Regarding Bill's mention of a hum that went away with his 845 amp when a shielded Belden cable was used, if the shield was connected at both ends, and assuming that an unbalanced connection was involved, my guess is that the hum had been caused by a ground loop issue between the amp and the component that was driving it. Depending on the designs of the specific components, ground loop susceptibility can be affected by the resistance of the return conductor in the cable which connects them. A shield can be expected to generally have a lower resistance than a wire of moderate gauge.
Regarding natural vs. artificial materials, it stands to reason that the characteristics of the insulating materials surrounding a conductor can affect the sonics of a cable in various ways. But I would be (very) hesitant to draw any general conclusions about natural vs. artificial without extensive and carefully controlled comparisons.
In any event, enjoy! Best regards,
-- Al
