A/D converter - The conversion of analog signals into digital signals. The analog signal is sampled every few milliseconds and its level is quantized into a digital word. The larger the digital word, the more accurate the representation of the analog value. See Quantization 1 and Sampling frequency The 02R uses 20-bit linear analog-to-digital converters for most of its analog inputs.
Aliasing - A form of distortion which can
occur during the conversion of analog signals into digital. If the input
signal is more than one half the sampling rate, only portions of the signal
will be present when the system samples the waveform. A false image of the
waveform based on the components that were actually sampled, is created.
A system which samples at 48 kHz can correctly process signals of up to
24 kHz. To remove signals above the Nyquist frequency (See Nyquist Sampling
Theory), all A/D converters employ anti-aliasing filters. The 02R employs
over-sampling A/D converters to allow the anti-aliasing filter to be performed
in the digital domain. See over-sampling.
Attenuation - After the signal has been converted to digital, the 02R can apply numerous forms of signal processing, such as equalization or effects. Some of these processes may boost the signal to digital clipping. The 02R allows you to attenuate the digital signal to reduce the chances of clipping.
Automation system - The 02R has an on-board automation system that memorizes fader positions, switches individual channels on or off adjusts the equalization or pan positions, and changes the auxiliary sends - all based on timecode. It can recall scene' memories and programs from the equalizer, effects, dynamics, and channel libraries, also determined by the recorded timecode. You can record an entire mixing session, and then edit the individual channel settings in multiple passes. You can punch-in to fine tune a specific parameter or you can use one of the event editors to adjust the timecode position of channel settings or scene and library changes.
Automix Memory - The automation system records each parameter change and the associated time as an event. The parameters that are recorded including fader movements, channel status and equalizer changes, and library recalls. The more complicated the mix, the more memory it consumes. The 02R has a default of 512 kbytes of automation memory.
Auxiliary send - The auxiliary sends arc used to feed signals from the input or tape return channels to external effects processors, amplifiers, or multitrack recording equipment. The 02R has eight auxiliary sends. Two of the sends feed the internal effects processors. See Internal Effects.
Bit - A single unit of digital data. It can have a value of 1 or 0.
Bulk Dump - A MIDI function that allow the transfer of system specific data, such as sample files or mixer settings, between MIDI capable devices. The data are transmitted as MIDI System Exclusive messages.
Bus - A circuit that connects the input or tape and effect return signals with the output connectors. The 02R has eight output buses plus the stereo output.
Compander - A compander is a compressor/expander - a combination of signal compression and expansion. The compander attenuates the input signal above the threshold as well as the level below the width. For very dynamic material, this program allows you to retain the dynamic range without having to be concerned with excessive output signal levels and clipping. See Dynamics Processor.
Compressor - A compressor provides a form of automatic level control. It attenuates high levels, thus effectively reducing the dynamic range, making it much easier to control signals and set appropriate fader levels. Reducing the dynamic range also means that recording levels can be set higher, therefore improving the signal-to-noise performance. Limiting is an extreme form of compression, where the output signal is sharply attenuated so that it cannot exceed a particular level. See Dynamics Processor.
Confidence monitoring - Listening directly from a recording medium to ensure the program material is being recorded correctly, Most analog recorders have a playback head trailing the record head, allowing you to hear the material directly after it has been recorded. Professional DAT recorders usually have four heads for confidence monitoring, as do a number of the modular digital multitrack recorders. Hard disk recorders offer their own form of confidence monitoring.
DAT cassette - Metal chrome cassette tape (thickness 13 (m, width 8.8mm).
Delay - A delay applied to the input signals processed by the 02R to compensate for signal processing delays, for example caused by the gap between the record and playback heads of a multitrack recorder.
Dither - Dithering is a mathematical process where a random noise is added to the least significant bit of a digital word. With very low level signals, the quantization error becomes correlated to the signal level. This creates a measurable amount of distortion. By adding dither, the correlation between the signal level and the quantization error is canceled, allowing the digital system to encode amplitudes smaller than the least significant bit. If you change the word size as a signal passes from one digital system to another, being able to add dither allows you to maintain a high quality signal.
Digital Signal Processor (DSP) - A specialized circuit, usually a chip, that is designed to manipulate large quantities of data in real-time. YAMAHA has developed world renowned expertise in proprietary musical application specific digital signal processing.
Ducking - Ducking is used to automatically reduce signal levels when the level of a source signal exceeds a specified threshold. It is used for voice-over applications where, for example, level of background music is automatically reduced, allowing an announcer to be heard clearly. See Dynamics Processor.
Dynamic range - The difference between the loudest (maximum output level) and quietest (residual noise floor) sounds produced in an audio system. The dynamic range in a digital system is determined by the data resolution, about 6 dB per digital bit. A 20-bit system has a theoretical dynamic range of 120 dB. The 02R has a specified dynamic range of 105 dB.
Dynamics Library - An area in 02R memory used to access and store dynamics settings - stored as programs. There are 40 preset programs (1 to 40) for you to recall and 88 user programs (41 to 128) for you to store your own dynamics settings.
Dynamics Processor - Dynamics processors are used to correct or control signal levels. The 02R features comprehensive dynamics processors for ,all the input channels, tape returns, and the bus and stereo outputs. These processors allow you to compress, expand, compress-expand (compand), gate, or duck the signals passing through the mixer. See Compander, Compressor, Ducking, Expander, and Gate.
Equalizer - The 02R is equipped with a four-band, fully parametric equalizer, with variable bandwidth (Q), center frequency (F), gain (G), and ON/OFF parameters, equalization can be applied to the input channels, the tape and effect return channels, and the stereo output. For stereo channels, the equalization curve is applied equally to both channels.
Equalizer Library - An area in 02R memory used to access and store equalizer settings - stored as programs. There are 40 preset programs (1 to 40) for you to recall and 88 user programs (41 to 128) for you to store your own equalizer settings.
Expander - An expander is another form of automatic level control. By attenuating the signal below the threshold, the expander reduces low-level noise or expands the dynamic range of the recorded material. See Dynamics Processor.
Gain and 20dB (pad) - The analog input pre-amplifier controls. These controls are used to optimize the signal from the input connectors. The pad switch is used to reduce the channel gain for line level signals.
Gate - A gate or noise gate is an audio switch used to mute signals below a set threshold level. It can be used to suppress background noise and hiss from valve (tube) amps, effects pedals, and microphones. See Dynamics Processor.
IEC958 Part-3 (AES/EBU - Professional) - A digital interface protocol that is used to transfer digital audio data between professional digital audio equipment such as PCM and DAT mastering recorders, modular multitrack recorders and other equipment. Two channels of digital audio are carried on a single line. An XLR-type connector and a shielded cable is typically used.
Internal Effects - The 02R is equipped with two internal multi-effects stereo processors. These processors have a startling range of special effects available to apply to your mix - shimmering reverbs, clean, precise delays, flanging and chorus, and a myriad of other effects are available.
MIDI implementation - MIDI is an acronym for Musical Instrument Digital Interface. It is an international standard that allows electronic musical instruments to communicate with each other. Because of the complexity of the 02R, it only recognizes MIDI Program Change. Parameter Change, and System Exclusive messages. It uses System Exclusive messages to provide bulk data transfers as well as controller changes. It also reads MTC (MIDI timecode). See Timecode.
Nyquist Sampling Theorem - This theorem defines the process of sampling audio with a digital system. Amongst other things, it states that the sampling frequency of a digital audio system must be at least twice that of the highest audio frequency, otherwise aliasing will occur. The Nyquist theorem was developed at Bell Labs by C. Shannon and H. Nyquist. See Aliasing.
Peaking - An equalizer circuit that is used to cut and boost a signal, centered about a specific frequency, Using the bandwidth (Q) parameter, you can widen or narrow the effect of the circuit.
Phase - Phase is the frequency coherence of a signal. If two signals are out of phase, the trough of the first waveform corresponds with the peak of the second, resulting in cancellation. The 02R can invert the phase of the input signals, which allows you to compensate for incorrectly wired conductors and so forth.
Program Change - A MIDI message that is used to recall programs 02R they recall scene memories.
Q (bandwidth) - The bandwidth of an equalizer band. For high values the bandwidth is narrow. For low values, it is wide. See Equalizer.
Quantization - The encoding process when the analog input is approximated (quantized) to the nearest binary value available. In the 20-bit system of the 02R, pulses are approximated to one of l,048,576 binary values. These approximations are not an exact duplication of the analog waveform and are therefore contain quantization errors (noise). However, this noise is reduced by over-sampling.
ROM (Read Only Memory) - A memory chip that stores data that cannot be edited. The 02R operating system is stored in ROM. Contrast with RAM.
Routing - The process of assigning input or tape and effect returns to the output buses or the stereo bus.
Sampling frequency - The rate at which measurements of an audio signal are taken during A/D and D/A conversion. Once in the digital domain, the data usually remains at the same sampling frequency. The measure is samples per second.
Scene Memory - The 02R scene memories are a memory location used to store a snapshot of virtually all the digital parameters of the mixer. Settings that are not stored consist mainly of monitor controls, analog controls, and switches. The 02R has 64 mix scene memory locations. Each can be named for easy identification.
Shelving - An equalizer circuit that is used to cut and boost a signal above or below a specified frequency High and low band equalizers are usually shelving type. The 02R equalizer can be configured as shelving or peaking.
Signal to Noise ratio (S/N) - The difference between the nominal signal level and the residual noise floor, usually expressed in decibels.
System Exclusive - A MIDI message that is used to transmit data between MIDI devices that is exclusive to those devices. Bulk dump data can be sent from any device to a MIDI data filer. Controller events are transmitted between 02Rs using System Exclusive messages. See also Bulk Dump.
Timecode - Timecode is a signal that contains
a chronological record of the absolute time in a recording. It is used for
synchronizing different recorders. It can be used for electronic editing.
Timecode was initially invented for the motion picture business, as a method
of synchronizing the pictures recorded in the frames of a camera to the
sound recorded on tape recorder.
The 02R supports three types of timecode, SMPTE timecode, MTC (MIDI timecode),
and Internal timecode.
Word - One sample of audio data.
Wordclock - Wordclock is a sync pulse which allows devices to determine where the start of each digital word is. When multiple digital devices are connected together, it is vital that each device knows where a digital word starts and stops. Otherwise dropout or distortion may result. Although most digital interconnect protocols are self-clocking, it is more reliable to use a dedicated line for your wordclock signal. This is especially important in a multitrack environment where up to eight channels of digital data may be multiplexed on one cable.