Entries found for search: loop
bin-loop master : A special tape that is used in cassette duplication equipment. It contains both sides of the tape and is either run at a very high speed or, for higher quality dubs, in real-time.
closed loop : A closed loop system is one which modifies its behavior based on the difference behavior between an output variable and a set point, i.e., it relies on feedback to determine its output. The opposite of open loop, an example of a closed loop system is a household thermostat. In audio, the main use for closed loop systems is in power amplifier output stages. See bootstrap.
cross-fade looping : A sample-editing feature found in many samplers and most sample-editing software, in which some portion of the data at the beginning of a loop is mixed with some portion of the data at the end of the same loop, so as to produce a smoother transition between the end of the loop and the beginning of the loop replay.
effects loop : A mixing console circuit that is used to add an effect to a signal or a group of signals. When the effect unit is plugged into the effects send bus circuit (via the effects send and effects return jacks), it literally functions as a loop, splitting the signal off from the mixer and sending it to the effect, then returning it to the mixer, where it is combined with the original signal.
multiple loops : The ability of a sampler to handle more than one loop in any given sample. Some machines allow only two loops per sample, while others allow as many as eight.
ground loop : The situation which arises when two pieces of equipment, each having an established chassis ground internally connected to signal ground, are then connected via a shielded cable. This forms a relatively large loop from chassis ground to signal ground (shield), shield ground to signal ground, and chassis ground back to chassis ground. Because the electrical pathway formed in this manner has a finite impedance, a difference in potential may occur from one end of the loop to the other, allowing an AC-frequency signal (usually at AC line voltage--50Hz or 60Hz, depending on where one is) to form in the circuit. This signal will manifest itself as a hum which can, in extreme cases, be louder than the audio signal. The solution is to break the screen connection between the two devices, ideally at the end of the cable that is plugged into a receiver, such as a mixer or amplifier with a ground lifter.
hysteresis loop : The graph of applied magnetic force vs. remanent magnetism. One measure of a specific recording tapeís performance.
loop : (1) A piece of material that plays over and over. In a sampler, loops are used to allow samples of finite length to be sustained indefinitely. See also sustain loop, release loop. (2) A section of tape with the two free ends joined, used for creating repeated sounds. Tape loops were used in the first delay units, where a short tape circulated around a system consisting of a record head followed by a series of replay heads to pick up the increasingly delayed signal (as well as an increasing proportion of noise). (3) In tape recorders equipped with zero-locators, a transport operating mode in which the engineer has designated a starting and ending point, either in tape time or SMPTE time code, and instructed the locator and machine to play the enclosed tape segment repeatedly, rewinding to the starting point each time the end point is reached. Most video interlock devices can be programmed to cause both video and any synchronized audio decks to repeatedly reproduce a loop of picture and its corresponding sound. The engineer may place the audio or video deck into record mode during a section of each repeat of the loop in order to replace dialog or other sync sound, or to perform insert edits. (4) In cameras and projectors, a slack section of film located just before and after the gate. The loop prevents tearing of the film as it passes from continuously turning sprockets to the intermittent movement of the supply reel. (5) A wire or cable system which has at least two ends joined together, usually creating ground loops. (6) An electronic connection where a device has a circuit from its output back to its input. See feedback.
looped recording : A sequencer option whereby a saved sample is played over and over again. The new data can either replace previously played data in real-time, or add to what was played previously.
looping : See ADR.
looping modes : A loop can play (1) forward from start to end, (2) in reverse from end to start, or (3) alternating between forward and reverse. Also called loop type. See also crossfade looping.
Loop Points Request : A Universal System-Exclusive message of the non-real-time type, within the SDS, which allows a receiving device (e.g., a sampler) to request that a transmitter (e.g., a computer) should send information about the two sample numbers between which a loop will occur.
Loop Points Transmit : A Universal System-Exclusive message of the non-real-time type, within the SDS, which allows a transmitting device (e.g., a computer) to request that a receiver (e.g., a sampler) should send information about the two sample numbers between which a loop will occur.
loop tempo : To find the exact tempo of a loop when you know the sampling rate that was used to make the sample (assuming you are using the sample at its original pitch), set the start point and the loop point at the desired points, and subtract the start pointís value from the loop pointís to find the length of the sample. For example, assume a two-bar 4/4 loop = eight beats, sampled at 32kHz. The loop (according to the sampler) is 135,500 sample words: (8 x 32,000 x 60) / 135,500 = 113.35 bpm.
MIDI loop : A (mistakenly) hard-wired loop. See note-doubling.
Multiple Loop Points : A category of message in the SDS which allows loop points to be determined or changed within a sampler independently of the sample itself, i.e., without having to retransmit the entire sample. Loop Points Request and Loop Points Transmit are two such messages.
release loop : A set of loop points that define a portion of the sound to be played repeatedly during an envelopeís release phase. A release loop starts playing back after a key is released when sample playback will finish the current pass through the sustain loop and then move on to the remainder of the sound, which may or may not contain a release loop. The release loop will be heard for the length of time determined by the release time parameter setting.
phase-locked loop (PLL) : A closed-loop electronic circuit that automatically adjusts and locks the frequency of an oscillator to the correct frequency for receiving a signal. The PLL is the preferred FM detector circuit in commercial systems today as it requires no tuned circuits, hence does not require alignment. It normally has high amplification which produces a strong output audio signal. Since it does not respond to amplitude variations, it also provides limiting action.
pattern looping : A digital composition technique whereby long, looped samples are mapped into a sampler along with other samples such as bass riffs, drum variations, and solo samples (vocal sounds, effects, etc.) The different loops and solo sounds are brought in and out via a keyboard to create a finished composition.
open-loop : An amplifier without feedback is said to be in an open-loop mode, or to be an open-loop amplifier. The feedback around the amplifier closes the loop.
sustain loop : A loop which cycles during the sustain segment of an envelope before the rest of the sample plays. See also release loop, loop.
tape loop : See loop(2).
Virgin Looping The process of recording onto a blank piece of mag film, which would later be manually synced to the picture. See looping and lip sync.