RCA Connection

RCA Analog Audio Cable

By far the most common type of A/V jack and plug, the two-wire RCA connector was standardized in the early days of radio by — guess who? RCA connectors are coaxial, with the signal-carrying conductor surrounded by an outer conductor shield connected to a ground. Occasionally referred to (confusingly) as “phono” plugs/jacks, mostly by old-timers, they’re also used to carry digital audio and analog video signals. RCA audio jacks and plugs are often color-coded in pairs: red for right-channel (“r” for right and red) and black or white for left-channel. Sometimes other colors are assigned to center- and surround-channel RCA jacks. All are electrically identical. RCA audio cables are often bundled in stereo pairs inside a single outer jacket.

XLR Cable

XLR Balanced Audio Cable

A three-wire connector — plus (+), minus (–), and shield — the XLR (or “microphone”) plug or jack is most commonly found in professional and broadcast equipment but is also used in some high-end consumer audio gear, usually for line-level connections between preamplifiers and power amps. By convention, three-pin male XLR connectors (whether panelmounted or at cable ends) are outputs, while female connectors are inputs. XLR cabling is used for balanced-line connections, which makes very low-level signals sent over long distances less susceptible to the noise and hum that can be caused by electromagnetic or radio-frequency interference from machinery, automotive electrical systems, and so on. In typical consumer setups the advantages are usually small.

"Head" Phone Cable

Mono/Stereo/AV Phone/Miniphone (Headphone) Jack

The 1/4-inch phone jack and plug got its name from its origins in early telephone switchboards (think Lily Tomlin). This connector is usually found on A/V gear in three-wire (stereo) form — left-channel, right-channel, and ground — as a front-panel headphone jack and the plug for a full-size headphone set. Phone connectors are also commonly used in professional and broadcast gear in two-wire form (signal and ground) for mono signals and occasionally for balanced signals in a mono three-wire form (+, –, shield). Identical in function to phone connectors, mini-phone plugs and jacks (1/8-inch diameter, bottom photos) are usually found in stereo form as headphone connectors for portable gear.

Digital Coax

Digital Coax(ial) Audio Cable

The identical RCA connector used for analog audio signals is also used for connecting digital audio components following the SPDIF (Sony–Philips Digital Interface Format) standard. A coaxial jack can carry either a stereo (CD format) or multichannel (Dolby Digital/DTS) digital audio signal and will be labeled as an input or an output. Jacks of either type are usually color-coded orange or black. Though any cable with RCA plugs at the ends can be used to make a digital audio connection, you should use a cable that’s specifically designed for digital audio to ensure the best possible signal transfer. In other words, use a cable that’s rated for 75 ohms impedance in which both the conductors and the plugs are coaxial.

Digital Optical

Digital Optical (Toslink) Audio Cable

Toslink optical ports pass the very same SPDIF-format digital audio data as coaxial RCA jacks, but they use pulsating light, instead of fluctuating electrical current, to carry the data. Toslink connections use special fiber-optic cables as the medium. The red light you see coming from an active Toslink output isn’t laser light and isn’t harmful. Dirt and dust can impede the optical link, so avoid handling cable ends, and keep dust caps in place over unused ports. Also avoid kinking Toslink cables, which can render them permanently useless.

F-Pin Coax

F-Pin/Coax (Antenna) Cable

The F-type coaxial connector, found on most receivers and preamp/tuners for hooking up an FM antenna, is engineered to transfer the minuscule radio-frequency (RF) electrical signals produced by antennas. It accepts either a push-on or a screw-on matching plug — the latter is what you’ll find on the end of cable-TV wiring or an indoor antenna system. An F-type plug is usually supplied with a receiver or preamp’s accessories, either fixed to an indoor FM antenna or in the form of an adapter for a Tshaped dipole antenna.

Composite Video

Composite (Yellow RCA) Video Cable

Compositevideo signals, so called because they carry both chrominance (color) and luminance (black-and-white) information along a single wire, use the same familiar RCA jack and plug as line-level analog and coaxial digital audio. Usually the jacks (and cables) are color-coded yellow. Any coaxial cable with RCA plugs can do an adequate job of transmitting composite video, but specialized video cables optimized for 75- ohm connections will yield superior images, especially over long runs, because they minimize impedance mismatches and signal reflections that can cause ghosting. Since composite video is the lowest-fidelity video signal format generally available, use S-video or component-video connections where quality matters.

"S" - Video

Super ("S") Video Cable

Because S-video uses separate wires for the chrominance and luminance segments of a color video signal, it can deliver noticeably better picture quality than the composite-video format, which crams everything into one wire. S-video employs a small four-pin plug (officially known as a mini-DIN connector) that you’re unlikely to encounter anywhere else. Be careful to orient S-video plugs correctly before inserting them: impatiently forcing one in the wrong way can easily bend the tiny pins, effectively ruining the cable. Don’t ask how I know this.

Component Video

Component (RGB/YPbPr) Video Cable

Component video cables carry signals that are broken down to three fundamental “components.” Since these are carried on three individual wires, they can convey even better image quality than S-video. Component-video cables are all terminated with familiar RCA jacks and may be bundled together, but they’re still electrically separate. The three component signals — luminance (Y) and color-difference signals derived by subtracting the luminance signal from two of the three primary colors (blue and red) — are labeled Y, Pb, and Pr, with the corresponding jacks and plugs usually colorcoded green, blue, and red, respectively. You can’t really hurt anything if you get the wires and jacks crossed up, but you’ll get results ranging from no picture at all to weird, unnatural-looking colors. Some DVD players use BNC jacks for their component- video outputs (see RGB+H/V just below). You might see component-video inputs and outputs described as “wideband,” “HDTV-ready,” “HDTV-capable,” and so on. These terms mean that signals from HDTV tuners, progressive-scan DVD players, line doublers, and other video processors can be handled with no problem and will display properly when they reach your high-definition TV or monitor. If high-def or progressive-scan signals go through a component connection that’s not wideband- capable at any point along the way to your TV, there’s a good chance that you will get a picture, but it will be very soft and lacking in high-definition detail.

RGB+H/V Cables

RGB+H/V (Red, Green, Blue + Horizontal and Vertical Sync)

The term RGB+H/V stands for red-green-blue plus horizontal and vertical sync signals. This is a long-standing pro-video/computer-monitor format that’s carried on into the HDTV era. You’ll find this five-jack input set on HDTV monitors and video projectors (including some nonhigh- def videophile models). Most commonly, RGB+H/V inputs and outputs employ BNC connectors (shown above), a professional- grade, bayonet-type plug and jack widely used on lab equipment that locks in place for an ultratight connection. Occasionally RCA connectors are used instead. You can get adapter cables with a VGA plug at one end and RGB+H/V plugs at the other from computer and pro-video sources, but they tend to be expensive. (For the insatiably curious: BNC stands for Bayonet Neill–Concelman, after the men who invented the connector.)

VGA Cable

DB15/VGA (Video Graphics Adapter) Cable

The VGA-graphics-standard 15-pin D-Sub connector is familiar to anyone who’s ever hooked up a monitor to a PC. In effect, VGA provides the same connections as RGB+H/V in a different physical configuration. VGA is found as a video output option on some HDTV tuners and as an input on some HDTV monitors and projectors.

DVI-I/D Cable

DVI (-I/D) Digital Visual Interface Cables

Like VGA and RGB+H/V, the DVI (Digital Visual Interface) connection is an immigrant from the computer world. It supplies a one-way path for digital video signals from source to display via a rectangular, 18-pin connector — for example, from an HDTV tuner to an HDTV monitor. Because a DVI connection eliminates the digital-to-analog conversion that’s required when a digital source has to pass through analog video connections (even wideband component video, RGB+H/V, and VGA are still analog), it holds the potential for improved picture quality from “digital,” fixed-pixel plasma, LCD, and DLP (Digital Light Processing) displays. DVI connections are found on many of the newest HDTV components, which incorporate a copy-protection scheme called HDCP (High-bandwidth Digital Content Protection) that prevents DVI signals from being copied.

HDMI Cable

HDMI (High Definition Multimedia Interface) Cable

The High-Definition Multimedia Interface, or HDMI, hasn’t arrived on any products yet, but it could become the standard connector of the future. For digital video, it’s essentially identical to DVI, on which it’s based, but it also carries both stereo and multichannel digital audio as well as signals for integrated remote control and infrared (IR) repeater functions — all on a single cable. The 19-pin HDMI connector is significantly smaller than a DVI connector, looking something like a USB jack and plug. HDMI-equipped HDTV monitors and source components (tuners and DVD players first) will probably begin to appear early next year. HDMI gear will be backwardcompatible with DVI-equipped components through cable adapters, though these arrangements won’t deliver the digital audio and control capabilities of all-HDMI hookups.

RS-232

Serial Communications DB9/RS-232 Cable

This nine-pin serial connector is found on some A/V components in the form of a DB-9 female jack. It is most commonly used to connect the component to a PC for control and communication, or to interface with home-automation systems such as touchscreen controllers.

USB Cable

USB (Universal Serial Bus) Cable

With rectangular or squarish plugs and jacks, the USB (Universal Serial Bus) has all but replaced old-fashioned nine-pin serial ports on personal computers and is fast becoming familiar to home-entertainment enthusiasts, too. The rectangular (or Type A) jacks shown are typically found on computers or other “hosts,” while the squarish (or Type B) jacks are found on peripherals. Among other uses, USB connections can transfer data between PCs, music servers, and portable MP3 players, and they’re used for audio and video input/output to computer recording/editing systems.

IEEE1394 Firewire Cable

IEEE1394 "FireWire" Cable

Apple Computer coined the name FireWire for the IEEE 1394 digital interface standard, and it has now been widely adopted, though Sony calls it i.Link and some jacks might use different names, such as DTV Link. Using a tiny rectangular, four-pin jack and plug, FireWire is a very high-speed (400 megabits per second, or Mbps), bidirectional, serial interface for digital devices: computers with hard-disk drives, video and audio editing systems with computers, DV camcorders with computers — or HDTV or satellite tuners with HDTVs. (A larger, six-pin connector found on computer equipment carries power as well as data.) Until the development of the HDCP (High-bandwidth Digital Content Protection) copy-protection scheme, the movie studios largely blocked it from being used for interconnecting HDTV components, but it is widely used for digital camcorder connections.

Telephone Jack

Telephone/Telecom (RJ-11) Cable

You’ll find modular telephone (RJ-11) jacks on certain components, primarily satellite tuners and harddisk video recorders, whose internal modems make dial-up network connections to transmit billing or program-guide data. You connect the RJ-11 jack on the component to a standard telephone wall jack (or to an extra jack on a phone) just as you would a telephone or answering machine.

Cat5/Cat5e/Cat6 Cable

Ethernet/Cat5/Cat5e/Cat6 (RJ-45) Cable

The RJ-45 network connector looks like an overweight modular telephone jack and works the same way (insert and click to plug in, press down on tab and pull out to unplug). Ethernet ports are becoming more common on components as network abilities migrate from computers to home-entertainment gear like receivers, hard-disk video recorders, and digital music servers. Almost any computer or electronics superstore will have network cables in lengths from a few feet to 50 feet with plugs already attached to the ends. If you’re handy, you could install room-to-room network wiring using bulk CAT-5 cabling yourself, but you’ll need special tools for attaching the wiring to jacks and plugs.