Читать книгу Home Recording For Dummies - Jeff Strong - Страница 71

A stereo/TRS (short for tip/ring/sleeve) ¼-inch plug looks like a stereo headphone plug (take a look at Figure 3-2). The tip is the end of the plug, the ring is the small middle section located between the two plastic dividers, and the sleeve is the rest of the metal part of the plug. A TRS plug can be used for the following three types of cords:

 Stereo cord: A stereo cord is used for signals that contain two separate portions: one for the right channel and the other for the left channel. This type of cord is generally wired with the left-channel signal attached to the tip, the right-channel signal connected to the ring, and the shield wired to the sleeve. This type of cord is typically used for headphones.FIGURE 3-2: Use a balanced (TRS) plug to connect professional audio gear.

 Balanced cord: A balanced cord is used on professional audio gear to join the various pieces of equipment (to connect the mixer to the recorder, for example). The advantage with a balanced cord is that you can have longer cord runs without creating noise. Why are balanced cords so conveniently noise free? The balanced cord has two wires and a shield inside and has the same signal running through both wires. One signal is 180 degrees out of phase with the other (that is, their waveforms are opposite one another), and when the signals get to the mixer (or whatever they’re plugged into) one of the signals is flipped and added to the other. When this happens, any noise that built up in the signal is canceled out.

 Y cord: A Y cord consists of a TRS plug on one end and two TS plugs on the other, forming — you guessed it — a nice representation of the letter Y. This cord allows you to insert an effect processor — a compressor or equalizer, for example — in the line of a mixer (more specifically, into the insert jack of the mixer). Check out Chapter 4 for details on mixers. The TRS plug both sends and receives a signal. This cord is wired so that the tip sends the signal and the ring receives it (see Figure 3-3). The sleeve is connected to the shield of each cable.

FIGURE 3-3: Use a Y cord to send and receive a signal.