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Another issue to take into account is the current-handling capability, or ampacity, of the cable. Again, this is mostly an issue for speaker cables and power cables, both of which need to carry high currents. These cables have a maximum current rating, measured in amperes (amps), that indicates what the cable can safely handle. The rating is based on the amperage a conductor can carry before melting either the conductor or the insulation. Therefore, when in doubt about ampacity, check with the manufacturer.

In general, the larger the conductor size, the greater the current-carrying capacity—that is, as long as the jacket is able to handle the heat. For example, 28-gauge wire can handle between 3 and 5 amps, while 4-gauge wire can carry between 125 and 180 amps. Of course, 4-gauge wire is overkill for most speaker applications; a typical speaker cable is 10 to 18 AWG. (Depending on how it’s constructed, 18-gauge wire can handle around 10 to 20 amps.).

Relief is in Sight
As a cable hangs off a piece of gear, the connector joint bears the weight of the part of the cable that is not resting on the ground. Eventually, this can cause the internal conductor and braiding to fray and even break. That’s why strain relief is another important factor in cable construction.

When selecting cables, be sure there is good strain relief at the ends, usually in the form of a rubber sheath that extends into the connector. Molded cables offer only fair strain relief and cannot be inspected or fixed if a problem arises. Soldered connectors are generally more robust, because they include better strain relief and you can open them up for repair.

Another important consideration—especially for mic and guitar cables—is how well the cable can handle the strain of being pulled on. Inside good-quality cable, the same filler that reduces handling noise also helps relieve pulling strain, taking the load off the connector. With inexpensive cable, however, the strain is borne solely by the solder joint between the conductor and the connector, which can cause the cable to fail after only one or two unfortunate tugs (or overly enthusiastic stage dives). In either case, the trick is to pull on the connector, not on the cable itself.

Upping the Ante
So far, I have covered the basics of cable design and described some ways in which cables can affect performance. Fortunately, most reasonably priced, well-made cables address these problems to a high degree. But for those seeking maximum audio performance, many types of so-called “exotic” cables are also available—typically at exorbitant prices.

Is exotic cable really worth the added expense? The answer depends on several variables, including whom you ask, how good your ears are, the listening environment, and the quality of the other components in the system. As suggested earlier, it makes little sense to buy the most expensive cables available if the rest of your system is not of similar quality.

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Reprinted with permission from Magazine, January, 2001
© 2001, Intertec Publishing, A Primedia Company All Rights Reserved