signal processing Signal processing is an electrical engineering subfield that focuses on analyzing, modifying and synthesizing '' signals'', such as sound, images, and scientific measurements. Signal processing techniques are used to optimize transmissions, ...

, a passthrough is a

logic gate A logic gate is an idealized or physical device implementing a Boolean function, a logical operation performed on one or more binary inputs that produces a single binary output. Depending on the context, the term may refer to an ideal logic ga ...

that enables a signal to "pass through" unaltered, sometimes with little alteration. Sometimes the concept of a "passthrough" can also involve

daisy chain Daisy chain may refer to: * Daisy chain, a garland created from daisy flowers * Daisy chain (climbing), a type of strap * Daisy chain (electrical engineering), a wiring scheme * Daisy chain (fishing), a type of fishing lure * Daisy chain (kno ...

logic.

Examples of passthroughs

Analog passthrough Analog passthrough is a feature found on some digital-to-analog television converter boxes. Boxes without analog passthrough only allow digital TV ( ATSC standard) to be viewed on older, analog-only ( NTSC standard) TVs. Those with analog passthr ...

(for

digital TV Digital television (DTV) is the transmission of television signals using digital encoding, in contrast to the earlier analog television technology which used analog signals. At the time of its development it was considered an innovative advanc ...

) *

Sega 32X The 32X is an add-on for the Sega Genesis video game console. Codenamed "Project Mars", it was designed to expand the power of the Genesis and serve as a transitional console into the 32-bit era until the release of the Sega Saturn. The 32X us ...

(passthrough for

Sega Genesis The Sega Genesis, known as the outside North America, is a 16-bit Fourth generation of video game consoles, fourth generation home video game console developed and sold by Sega. It was Sega's third console and the successor to the Master Syst ...

video games) *

VCR A videocassette recorder (VCR) or video recorder is an electromechanical device that records analog audio and analog video from broadcast television or other source on a removable, magnetic tape videocassette, and can play back the recording ...

DVD recorder A DVD recorder is an optical disc recorder that uses optical disc recording technologies to digitally record analog or digital signals onto blank writable DVD media. Such devices are available as either installable drives for computers o ...

s, etc. act as a "pass-through" for

composite video Composite video is an analog video signal format that carries standard-definition video (typically at 525 lines or 625 lines) as a single channel. Video information is encoded on one channel, unlike the higher-quality S-Video (two channe ...

and

S-video S-Video (also known as separate video, Y/C, and erroneously Super-Video ) is an analog video signal format that carries standard-definition video, typically at 525 lines or 625 lines. It encodes video luma and chrominance on two separate chan ...

, though sometimes they act as an

RF modulator An RF modulator (or radio frequency modulator) is an electronic device whose input is a baseband signal which is used to modulate a radio frequency source. RF modulators are used to convert signals from devices such as media players, VCRs an ...

for use on Channel 3. *

Tape monitor Tape or Tapes may refer to: Material A long, narrow, thin strip of material (see also Ribbon (disambiguation): Adhesive tapes * Adhesive tape, any of many varieties of backing materials coated with an adhesive *Athletic tape, pressure-sensitiv ...

features allow an

AV receiver An audio/video receiver (AVR) is a consumer electronics component used in a home theater. Its purpose is to receive audio and video signals from a number of sources, and to process them and provide power amplifiers to drive loudspeakers and r ...

(sometime the recording device itself) to act as a "pass-through" for audio. *An

usually allows pass-through of the video signal while amplifying the audio signal to drive speakers.

Examples of passthroughs

See also