directional cables?


My IC cables are directional, with arrows pointing the way they should be hooked-up. Q: Should they run with the arrows pointing to my cd player, or to my integrated amp? Thanks.
tbromgard

Showing 6 responses by nsgarch

The "arrow convention" was started by Bruce Brisson when he developed the "shotgun" interconnect while at Monstercable (he left to start MIT cables.)

Cable manufacturers now put arrows on everything! However the arrows were originally meant only for single ended shotgun type interconnects, and have nothing to do with "signal flow." The arrows always point to the end of the (single ended shotgun) interconnect where the shield and the negative signal conductor are soldered together to the ground 'ring' of the RCA plug. The other end of the shield is not connected to the RCA plug (it 'floats'.)**

I think the business about "signal flow" was concocted so technologically challenged audio salesmen could explain cable installation to their customers ;--)) It's too bad this nonsense got started, when it would have been just as easy to say "All arrows should point to the preamp." This would have insured proper star-grounding, with the preamp at the center of the star, and avoided the resulting (and common) mistake of installing the preamp-to-amp cables backwards.

Arrows on all other kinds of cables -- XLR, speaker, power, and data -- are utterly meaningless from an electrical standpoint, since audio signals (and wall voltage) are alternating current and interact with conductors the same way in either direction.

** If you want to check, and have a single-ended interconnect with removable connector barrels (and arrows ;--) you can slide the barrels back and you will see that only he arrowhead end has the shield soldered to the RCA connector. At the other end, the shield has been trimmed short, and usually covered with a piece of tape or shrinkwrap.
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Grounding the shield on the cable at the "source" produces the least noise (hum). That is the reason for the "direction".
Don, I'd be interested in the science on which you base this pronouncement ;--))

Clio, the cable you describe is either:
(1) the old (pre-shotgun) coax that was used to connect all the early RCA enabled equipment; a 'hot' conductor in the center with a 'ground' conductor/shield around it, much like today's CATV cable, OR
(2) some current manufacturers (like Nordost, I think) are offering air-dielectric single-ended interconnects that use teflon tubing and no shield.

The reason for floating the shield is because if connected to ground at BOTH ends, it can conduct a current -- such current can be the music signal, but it can also include that created by nearby electromagnetic sources (power cords, transformers) or by airborne radio waves. If you disconnect the shield at one end, it can still drain interference to the ground end, but it can no longer conduct the 'minus' half of the music signal.

In "pre-shotgun" days, one of the biggest problems people had (with the old coaxial interconnect) was with their record players -- especially after the introduction of stereo, which meant having TWO parallel coaxial interconnects (with shields connected at both ends) creating a nice BIG loop antenna, enabling you to hear both your record AND a local radio broadcast at the same time!!

BTW, the term "shotgun" simply refers to the fact that instead of having a single center conductor (for the 'hot' signal) and a signal conducting shield surrounding it, the new "shotgun" cable had TWO signal conductors in the center (doubled barreled shotgun ;-) with a floating, non-conducting protective shield surrounding them.
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Jea48, you (and they) are talking about the crystalline structure of the conductor metal, and yes, it *can* sometimes have an asymmetrical geometry that lets electrons flow better in one direction than another (the basis of solid state devices by the way.) This is also the reason some cable manufacturers boast of "single crystal" wire which presumably has no impeding geometry.

However, I was referring to the issue of the signal itself having a direction, which it can't, because it's an alternating current, constantly reversing it's polarity.

Herman -- energy is only "transferred" when it does some work. Until then, it's only "potential energy" (as in 'voltage' potential.) It really doesn't matter whether the voltage potential is of constant polarity (direct current) or variable polarity (alternating current), there is no "work" being done in the transmission line itself (other than some heat generated if the conductors are too small for current to flow through them unimpeded.) In direct current, the electrons do indeed flow in one direction, and thus "the load" (where the "work" is done) becomes an impediment to the flow of electrons through the entire system -- and which is why DC can only be transmitted a short distance -- and which is why Edison lost to Westinghouse and AC ;--)) Nevertheless, none of these things affect (or are affected by) the way the metal crystals in the conductor material happen to line up (or not.) As with all things, there are exceptions, the most common being ultra-high frequencies. Normal high frequencies (like in audio) just take the easy way out, and travel on the surface of the conductor(s) if there's enough of it.
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Clio, the Mogami 2549 is ideal for making shotgun interconnects, using the two center conductors for the signal (hot and return), and floating the shield at one end.

Stan, the kinds of conditions you mention are "direction neutral" in the presence of an alternating current such as a music signal. They can sometimes alter frequency response due to capacitive effects, similar to the boundry interface between conductors and dielectric materials, but again, the physical orientation of such an interface between two materials would not change its effect (if any) on the frequency curve of the signal.
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Herman, if you want to nit pick about the physics of energy transmission (which is NOT what my remarks here concern) then we can have that conversation privately, and not bore these folks. Is sounds like you accept that a cable (material) will conduct a signal the same way regardless of which end is used at the source and which at the load, or do you disagree with that?

As for the arrows, they simply indicate at which end of a single ended audio frequency cable the shield is tied to ground. This helps to select a common piece of equipment (usually the preamp) as the single grounding point for all the signal cables.

Placing arrows on other kinds of cables commonly used in audio, as if to imply their design is soooo sophisticated that their performance will be affected by their orientation, is a silly marketing ploy used to raise their perceived value in the eyes of unsophisticated consumers ;--)

I do know of one high end cable manufacturer whose glass digital data cables do render different analog results depending how they are installed. I won't even go there, God forbid I've lost my grasp on that technology as well ;--)
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In the early 80's, at Christopher Hansen's audio showrooms in Beverly Hills, I had the pleasure of meeting Bruce Brisson right after he left MonsterCable, and had begun making his famous MI330 interconnect and Music Hose speaker cable. He was there to train Chris's technicians to prep the epoxy-coated wire and terminate his cables; since he was still in the process of putting together a manufacturing facility. He was very clear that the arrows printed on the cable should point to the end where the shield was tied to ground. This was only the the second interconnect product on the market, at that time, to carry such indicators on the jacket (the first being the IC's Bruce designed at Monster.)

Neither product had any printed text on the jacket to indicate what the arrows meant, and it was Noel Lee of MonsterCable (great marketer that he is) who first came up with the "signal flow" idea, which was mentioned in the packaging but never printed on the cables themselves.

The only other (consumer audio) cable makers at that time were Straightwire, which made the standard coax stuff and Kimber which had his famous braided design. Audioquest followed a few years later. Mogami (preceding all of them) remained in pro-audio field.

Unfortunately, and probably due to Noel Lee's playing fast and loose with the science (like some on this thread) no standard was ever adopted. But for the first post-Monster decade at least, arrows appeared ONLY on shotgun-type single-ended interconnects.

Today, arrows appear on every kind of audio cable and power cord, mostly meaningless for any practical purpose. There are a least three manufacturers (Purist, Magnan, and Aural Symphonics) who each use different, and unconventional shielding topology, and who also mark their cables with arrows. Those people are very open, if you care to contact them as I have, about how their cables are designed and how the arrows relate to each of those designs.

One manufacturer I know of, Cardas, and maybe others, does build a shotgun-type single-ended interconnect which CAN be used in either direction. This is because the interconnect has TWO concentric shields, insulated from each other, with each shield tied to ground at opposite ends of the cable. I think those have arrows on them too!

Tbromgard, those are the historical facts. The answer to your original question UNFORTUNATELY depends on the construction of the specific cable you are using. Any of the better-known brands will follow Bruce Brisson's original shotgun design (so point all arrows to the preamp.) If you're not sure, call the manufacturer, and ask specifically what the conductor layout is, and if the cable has a floating shield. If they hedge, or don't seem to know what a floating shield is, or God forbid!, tell you the arrows point in the direction of the signal flow, then you might want to consider replacing your cables with ones from a more reputable manufacturer ;--)

Sorry your thread got hijacked.