So you’ve got a rat’s nest of cords, you don’t know which are good or bad, or what to do about it. How do we check them? And once determined to be bad, how do we fix them?
One really handy way to check them is a “Cable Tester” like the Behringer CT-100. There are other types available, too, and they’re a really good way to check your cords and cables prior to an important gig or session. I find these (I have 2 different kinds) very useful in my shop. If you’ve got a band, your band’s gear should include a Battery Checker, a Receptacle Tester, and a Cable Tester, and of course, someone needs to know how to use them. Make sure to use the Battery Checker to check the batteries in the other testers, and no, simple Battery Checkers don’t need batteries…
In general, there are (3) kinds of cords that you use:
- Instrument cable. These are coaxial (like a bull’s eye in cross section), with a center conductor (hot) and a braided outer shield (ground), separated and covered by an insulator.
- Balanced microphone cable. These are also coaxial, but with 2 conductors in a twisted pair (hot & cold) in the center and a braided outer shield (ground), also separated and covered by an insulator.
- Speaker cable. These will be a pair (speaker + and -) of equal gauge (size) wire, usually between #16 gauge and #12 gauge, covered by an insulator. There are smaller and larger types, also. Remember: the larger the AWG wire number, the smaller the wire.
It is worthwhile to note that improper use of cables and cords will result in anything from poor performance to actual damage to your equipment. Please use the correct cord for the application, and please do not use a guitar cord as a speaker cable!!! Stuff might actually catch on fire, and we don’t want that!
The plugs on either end of your guitar cord are called “¼” T/S Phone Plugs”. The “T/S” stands for “Tip/Shield”. The long part of the plug is the shield, and is connected to the grounded outer braid. The little tip is connected to the center ‘hot’ conductor. You will also see “¼” T/R/S Phone Plugs” used on “Balanced” cables, Insert/Compressor cables, FX cables, and used in stereo applications such as Headphone plugs. “T/R/S” stands for “Tip/Ring/Shield” and refer to the tip, ring (behind the tip), and shield of the plug.
Microphone cables are usually tipped with what are called XLR connectors, male (has pins) and female (has sockets). Usually having only three pins, they are labeled Pins 1, 2, & 3. Pin 1 is the ground/shield, pin 2 is usually ‘hot’ and pin 3 is ‘cold’. The inner wires may be red/black, black/white, red/white, blue/brown… Whatever. If you’re doing your own, just consider the lighter color to be ‘hot’ and you’ll be good at both plugs.
Speaker cable can be either ¼” phone plugs, bare wire for posts, “banana plugs”, or “Speak-on” connectors: big guys that twist-lock into the cabinet. The main difference here is that speaker cable is designed to carry current. Lots of current = lots of power. Guitar cables, and microphone cables, are designed to quietly (shhh) carry just milliamps – little teeny-weeny tiny whispers of electricity. A “speaker cable” carries the screaming output of overdriven 6L6’s!! OK, so you’ve got aMarshall– EL34’s, then.
Electricity has to travel in a circle. That circle is called a circuit. There are three kinds of circuits: Open, Shorted, and Good/Working. Electricity moves in a wire a lot like water flows in a pipe. That’s why the Europeans call tubes “valves”, I guess – makes sense. Anyway, if the circuit is open, there’s no path for the electricity, and nothing gets done. If the signal is shorted to ground, it’s like a big hole in the pipe, the entire signal goes ‘zip’ home to the ground, and nothing gets done.
Cord testers check “continuity”. Does the hot/cold conductor on one end connect reliably with the hot/cold conductor on the other end? And does it not connect to ground in any way? Is the ground connection solid? If all three conditions reliably prevail, then your cord is good. Repairing cords is fun and interesting, but you’ll need a soldering iron, tools, and stuff to do it. Another article will coming regarding that subject.
Armand Blake, Owner: AMPWERX Repair
1935 E. 7th. St.Long Beach,CA90813
Tel: 562-591-1423 Fax: 562-591-1423