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I am thinking about building more interconnects for pre-amp to power-amp. They need to be 8 to 10 feet long. I am thinking of a co-axial design of 24g silver coated copper wire with a silver coated copper shield. Currently I am using a twisted pair with a shield constructed of the same type of silver coated copper wire. I am curious about having the positive leg of different geometry than the return leg. Any opinions? Nothing I have built before has different geometries between the 2 legs.
The shielded twisted pair I am currently using has a capacitance of a whopping 93.8/ft
The coax has capacitance of 19.8/ft
I'm also considering the VH-audio v-twist which is way more expensive but capacitance of 11.3/ft.
Probably going to mate them with the Neutrik ProFi RCAs I usually use.Your thoughts?
Edits: 07/20/16Follow Ups:
By "having the positive leg of different geometry than the return leg" mean an asymmetrical relationship based on different conductor materials, twist ratio, or gauge? A twisted pair benefits greatly via a perfectly symmetrical relationship of the two opposing conductors for a mirror image topology of the positive and return legs along the entire length of the cable, from end to end. However, there are hybrid designs that are considered favorable, but an unshielded cable like the V-Twist with perfect symmetry offers excellent performance with no downside when it comes to a predictably excellent, high-performance sonic signature with overall transparency vs. what might be expected from an experimental DIY build. While the gold plated brass Neutrik Profi rca connector might be an okay compromise for a more affordable DIY project, the V-Twist deserves a higher performance connector, IME.
Thanks for the valuable information. Whatever I do, I think I will terminate with the newish KLE RCAs; probably the high end ones since the best ones are not all that much more than either of the other two. So after eliminating the coaxial design based on advice here, I was looking at some other twisted pairs that are substantially cheaper than VH-Audio's V-twist. This is what I am currently using that has the really high capacitance:
Other possibilities are this twisted pair of 24 AWG silver plated stranded teflon insulated wire:
This is a 20 AWG twisted pair insulated with PTFE and an outside jacket of PTFE
If the difference between stranded and solid wire is important, I could easily twist up something using this 24 AWG PTFE solid core wire
Finally, there is a nickel plated twisted pair "space station" wire that should sound out-of-this-world!
Any thoughts on these alternatives to the $15/foot stuff? These options are about 1/10th that cost.
Thanks in advance.
Edits: 07/24/16
The wires in the photo's you posted all have insulation that is fairly thin. This results in a wire to wire spacing that is fairly close, and even though the insulation quality may be high, it is still going to be manifesting at near 100% effect on the electric fields.
This is one reason that your capacitance per foot is so high.
This thin insulation on the wires is also one reason the shields can have deleterious effects, as it ends up too close to the wires, and interrupts and distorts the electric and magnetic fields. With a good even, tight and consistent twist, the shielding is not needed as much, but often, removing it can help audibly, just because it is too close.
Now, if that wire assembly were to be "taken apart" or disassembled, then you could use the raw individual wires, and ADD some spacing using a benign material such as cotton rope. It wouldn't have to be a very thick rope, in fact you probably wouldn't want something much thicker than the wire and insulation diameter itself. An alternative would be some foamed teflon valve stem sealer. Two or three of these spiraled together, and then the wires twisted around them in the opposite direction would provide some space between the two signal wires.
This would retain most of the benefits of a twisted pair, but reduce the capacitance for such a long run. A 10 foot cable would need to be a decently low C, so this would one way to do so, without the loss of the balanced configuration.
If additional spacing were added, then a shield could be added back onto the twisted pair with the expanded dimensions, but it may have to be a braid from another cable, in order to fit over the now much larger diameter total assembly.
Try to stay away from plated materials, use pure copper or pure silver, the outer shield of a twisted pair is not as critical for materials.
Jon Risch
For some of the rationale, and info on what I said in the post above, see:
http://www.geocities.ws/jonrisch/i1.htm
NOTE: DO NOT CLICK ON ANY OF THE LINKS AT THIS SITE! It is a ghost site of the now defunct Geocities web page hosting, and may link to bad things.
You can go to the following to complete the article:
http://www.geocities.ws/jonrisch/i2.htm
Also see these here at the Asylum:
Assembly of twisted pair using cores from 89259, etc.
http://www.audioasylum.com/audio/cables/messages/99543.html
Assembly of balanced twisted pair:
http://www.audioasylum.com/audio/cables/messages/109148.html
Latest post:
http://www.audioasylum.com/audio/cables/messages/113781.html
Note that the same basic techniques can be used for your teflon insulated wires, but with the added core to increase spacing.
Jon Risch
Jon Risch-89259/89248 twisted pair IC'S
Why do you use two different types of coax cores for this construction? I'm still wading through all your information!
There is not just the electrical aspect only of the cables, but other concerns, such as how the wire assemblies react to mechanical stimulation (sound from the speakers) and their own motor/generator action (sometimes referred to as magnetostriction of the overall cable).
Having different diameter/mass and types of wires and insulators, spreads out the mechanical resonances, reduces any tendency for one physical parameter to reinforce another, and thus create an actual spurious frequency pattern or signature.
In my own studies of DIY cables, using cores of both 89259 or both 89248 did not sound as clean and pure overall as a combination of the two.
Jon Risch
I'll take your advice Duster but why is Mil Spec stuff bad and the "audiophile" stuff good? Mil spec has to meet some reasonably stringent standards which the "audiophile" stuff does not.
Since the criteria is different, high-performance wires and cables designed for audio signal applications can actually have very high standards that directly affect audio signal quality, and can be quite expensive to manufacture vs. mil-spec wire not designed for audiophile use. This is why all audio cables are *not* created equal, since there is a wide-range of considerations, engineering, and production costs that affect the price and performance of various audiophile products. An important aspect to consider is silver plated copper mil-spec conductors tend to impart a very identifiable sonic signature that tends to artificially color the audio presentation, including a level of glare, with a lack of natural-sounding timbrel information being most notable, IME.
Silver plated mil-spec, aerospace/avionics, and other wire/cable not designed for audio signal applications may look impressive, but are substandard for audiophile use. If you were to build short-length cables rather than up to 10 feet long, a simple hand-built twisted pair using VH Audio 21 AWG OCC copper hookup wire with AirLok insulation would be a far better option than the cables/wires shown. I have built outstanding short-length cables using that particular VH Audio wire, especially since the 21 AWG solid core wire with minimal-mass insulation is quite easy to *evenly twist* and *keep its shape* vs. other wires, IME. However, it would be a challenging effort to construct a precision twist using two 10 foot wires. For such a long length, unless a custom jig is used to help build a precision twist of such long-length wires, a pre-built audiophile cable is more advisable, IMO.
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