Patch panel
Encyclopedia
A patch panel or patch bay is a panel, typically rackmounted, that houses cable
connections. One typically shorter patch cable
will plug into the front side, whereas the back holds the connection of a much longer and more permanent cable. The assembly of hardware
is arranged so that a number of circuits, usually of the same or similar type, appear on jacks for monitoring, interconnecting, and testing circuits in a convenient, flexible manner.
s, television and radio broadcast studios, and concert sound reinforcement systems, patchbays are widely used to facilitate the connection of different devices, such as microphones, electric or electronic instruments, effects
(e.g. compression, reverb, etc.), recording gear, amplifier
s, or broadcasting equipment. Patchbays make it easier to connect different devices in different orders for different projects, because all of the changes can be made at the patchbay. As well, patchbays make it easier to troubleshoot problems such as ground loop
s; even small home studios and amateur project studios often use patchbays, because it groups all of the input jacks into one location. This means that devices mounted in racks or keyboard instruments can be connected without having to hunt around behind the rack or instrument with a flashlight for the right jack. Using a patchbay also saves wear and tear on the input jacks of studio gear and instruments, because all of the connections are made with the patchbay.
Example: a 16-point S-Video
patch panel, with 8 patch cables, cost may start at $150.00, and connect 8 inputs and 8 outputs. An S-Video matrix routing switcher with the same capability (8x8) would probably cost between $2,000.00 and $4,000.00 new, though it would probably have more capabilities, including audio-follow-video and built-in distribution amplifier
s.
There are various types of switchers for audio and video, from simple selector switches to sophisticated production switchers. However, emulating or exceeding the capabilities of audio and/or video patch bays requires specialized devices like routing switchers and matrix routers (aka "crosspoint switchers").
Like patch panels, switching equipment for nearly any type of signal is available, including analog and digital video and audio, as well as RF
(cable TV), MIDI, telephone, networking, electrical, and just about anything else.
Switching equipment may be electronic, mechanical, or electro-mechanical. Some switcher hardware can be controlled via computer and/or other external devices. Some have automated and/or pre-programmed operational capabilities. There are also software switcher applications used to route signals and control data within a "pure digital" computer environment.
Distribution frame
s are cheaper, but less convenient.
Cable
A cable is two or more wires running side by side and bonded, twisted or braided together to form a single assembly. In mechanics cables, otherwise known as wire ropes, are used for lifting, hauling and towing or conveying force through tension. In electrical engineering cables are used to carry...
connections. One typically shorter patch cable
Patch cable
A patch cable or patch cord is an electrical or optical cable used to connect one electronic or optical device to another for signal routing. Devices of different types are connected with patch cords...
will plug into the front side, whereas the back holds the connection of a much longer and more permanent cable. The assembly of hardware
Hardware
Hardware is a general term for equipment such as keys, locks, hinges, latches, handles, wire, chains, plumbing supplies, tools, utensils, cutlery and machine parts. Household hardware is typically sold in hardware stores....
is arranged so that a number of circuits, usually of the same or similar type, appear on jacks for monitoring, interconnecting, and testing circuits in a convenient, flexible manner.
Uses and connectors
In recording studioRecording studio
A recording studio is a facility for sound recording and mixing. Ideally both the recording and monitoring spaces are specially designed by an acoustician to achieve optimum acoustic properties...
s, television and radio broadcast studios, and concert sound reinforcement systems, patchbays are widely used to facilitate the connection of different devices, such as microphones, electric or electronic instruments, effects
Sound effect
For the album by The Jam, see Sound Affects.Sound effects or audio effects are artificially created or enhanced sounds, or sound processes used to emphasize artistic or other content of films, television shows, live performance, animation, video games, music, or other media...
(e.g. compression, reverb, etc.), recording gear, amplifier
Amplifier
Generally, an amplifier or simply amp, is a device for increasing the power of a signal.In popular use, the term usually describes an electronic amplifier, in which the input "signal" is usually a voltage or a current. In audio applications, amplifiers drive the loudspeakers used in PA systems to...
s, or broadcasting equipment. Patchbays make it easier to connect different devices in different orders for different projects, because all of the changes can be made at the patchbay. As well, patchbays make it easier to troubleshoot problems such as ground loop
Ground loop (electricity)
In an electrical system, a ground loop usually refers to a current, almost always unwanted, in a conductor connecting two points that are supposed to be at the same potential, often ground, but are actually at different potentials. Ground loops created by improperly designed or improperly installed...
s; even small home studios and amateur project studios often use patchbays, because it groups all of the input jacks into one location. This means that devices mounted in racks or keyboard instruments can be connected without having to hunt around behind the rack or instrument with a flashlight for the right jack. Using a patchbay also saves wear and tear on the input jacks of studio gear and instruments, because all of the connections are made with the patchbay.
Normalling
It is conventional to have the top row of jacks wired at the rear to outputs and bottom row of jacks wired to inputs. Patch bays may be half-normal (usually bottom) or full-normal, "normal" indicating that the top and bottom jacks are connected together internally. When a patch bay has half-normal wiring, then with no patch cord inserted into either jack, the top jack is internally linked to the bottom jack via break contacts on the bottom jack; inserting a patch cord into the top jack will take a feed off that jack whilst retaining the internal link between the two jacks; inserting a patch cord into the bottom jack will break the internal link and replace the signal feed from the top jack with the signal carried on the patch cord. If a patch bay is wired to full-normal, then it includes break contacts in both rows of jacks.Switches
Dedicated switching equipment can be an alternative to patch bays in some applications. Switchers can make routing as easy as pushing a button, and can provide other benefits over patch bays, including routing a signal to any number of destinations simultaneously. However, switching equipment that can emulate the capabilities of a given patch bay is much more expensive.Example: a 16-point S-Video
S-Video
Separate Video, more commonly known as S-Video and Y/C, is often referred to by JVC as both an S-VHS connector and as Super Video. It is an analog video transmission scheme, in which video information is encoded on two channels: luma and chroma...
patch panel, with 8 patch cables, cost may start at $150.00, and connect 8 inputs and 8 outputs. An S-Video matrix routing switcher with the same capability (8x8) would probably cost between $2,000.00 and $4,000.00 new, though it would probably have more capabilities, including audio-follow-video and built-in distribution amplifier
Distribution amplifier
In electronics, a distribution amplifier or simply distribution amp, is a device that accepts a single input signal and provides this same signal to multiple isolated outputs....
s.
There are various types of switchers for audio and video, from simple selector switches to sophisticated production switchers. However, emulating or exceeding the capabilities of audio and/or video patch bays requires specialized devices like routing switchers and matrix routers (aka "crosspoint switchers").
Like patch panels, switching equipment for nearly any type of signal is available, including analog and digital video and audio, as well as RF
Radio frequency
Radio frequency is a rate of oscillation in the range of about 3 kHz to 300 GHz, which corresponds to the frequency of radio waves, and the alternating currents which carry radio signals...
(cable TV), MIDI, telephone, networking, electrical, and just about anything else.
Switching equipment may be electronic, mechanical, or electro-mechanical. Some switcher hardware can be controlled via computer and/or other external devices. Some have automated and/or pre-programmed operational capabilities. There are also software switcher applications used to route signals and control data within a "pure digital" computer environment.
Distribution frame
Distribution frame
In telecommunications, a distribution frame is a passive device which terminates cables, allowing arbitrary interconnections to be made.For example, the Main Distribution Frame located at a telephone central office terminates the cables leading to subscribers on the one hand, and cables leading to...
s are cheaper, but less convenient.