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To learn more about what goes into making a quality cable, I called Dave Russell, the founder of Spectraflex, and asked him to share his insights. If you’ve ever been in an Otis elevator, had a CT scan, or flown a B-1 bomber, chances are you’ve been closer to a Spectraflex cable than you realize. Russell took the knowledge he gathered from making cables for aircrafts, elevators, and medical equipment and applied it to manufacturing high-quality instrument cables.
“When you play a note on a guitar,” says Russell, “the string vibrates and that energy is detected by your pickup. The signal goes through your guitar’s electronics and down to your input jack. From there, what travels through your cable is an electrical imprint of the sound, not the sound itself.”
Through my conversations with Russell, I learned that the signal from your guitar travels down a copper wire inside the instrument cable at the speed of electricity, which is around 66 percent of the speed of light—or 122,760 miles per second (the speed of light being approximately 186,000 miles per second). Once the signal travels through your amplifier and comes out of a speaker, the note is traveling at the speed of sound, which is 768 miles per hour in dry air at 68 degrees.
Now, with that bit of science in mind, let’s venture inside the cable and look at its components, beginning with the copper wire. The center conductor of a cable is made out of stranded copper wire. These copper strands, as opposed to a solid copper conductor, allow the cable to be flexible. On a standard guitar cable, there are about 41 36-gauge copper strands that make up a standard 20-gauge center conductor. Copper is a good material because it is highly conductive. Other metals that are also very good conductors are gold, silver, and platinum. But when you’re making a $20 guitar cable that’s going to get stepped on and thrown around on tour, those precious metals are not the most cost-effective materials. Right now, copper costs about four bucks a pound. Gold is selling for around $1400 an ounce, so you can see why center conductors in guitar cables are not made out of gold!
Another important aspect of an instrument cable is the shielding. Shielding takes on two different roles. “The first role of shielding in a bi-directional cable—which describes a standard high-impedance instrument cable—is to complete the signal from your guitar to your amp by implementing the return signal,” says Russell. “The second role of shielding is to block electromagnetic interference from the outside world, such as radio stations, fluorescent lights, aircraft, missiles, UFOs, warps in the space-time continuum, and black holes.” [Laughs.]
Poor shielding in a cable can affect your tone by letting a radio signal, hum, or buzz into your sound. So you always want to use a cable that has sufficient shielding. When you test a cable, shake it around to see if it makes any crackling sounds. Noise can be caused by a loose solder joint or shielding moving around inside the cable. In a well-built cable, you won’t hear any crackling, because all the components inside the cable are being held in place properly.
Along with shielding and center conductors, cables also have a layer called the dielectric. The dielectric is the white-colored material that covers the center conductor. The dielectric physically and electrically insulates, or separates, the center conductor from the shield. It also contributes significantly to the characteristics of the tone, depending on its size and the material from which it’s made.
As you probably know, solder is the silver-colored material used to connect the wire to the cable’s plug. Typical solder is made of lead and tin. Individually, tin and lead are fair electrical conductors, but both require extreme heat to melt, which makes them impractical for use in electrical connections. Too much heat can damage other components that are close to the area you’re soldering. When you combine tin and lead, they melt at a lower temperature and provide a good conductive connection. Some cable companies, such as George L’s, offer cables that don’t require any solder at all. George L’s also sells kits for making your own cables, which is a great option if you like DIY projects.
Several companies make high-quality cables, so your choice depends on what kind of sound you are looking for and how much you want to spend. Most guitarists use a trial-and-error process—similar to testing strings—to find the cable that best suits their needs. Some companies, like Monster Cable, offer cables that are designed for specific genres of music and specific instruments. The two main reasons I prefer Spectraflex’s Original Series cables are that they sound great and have been 100-percent reliable for over a decade. Happy cable hunting!