Unit of electrical power named after its founder, James Watt.

A guitar effects device where a bandpass filter is varied in frequency by means of a pedal control.

A specific way of mounting two directional microphone capsules such that they both receive sound waves from any direction at exactly the same time. Information about the direction of a sound source is captured in the form of level differences between the two capsule outputs. Commonly, the two microphones in an X-Y array are mounted with a mutual angle of 90 degrees, although other angles are sometimes used. The two capsules will have the same polar pattern, the choice of which determines the stereo recording angle (SRA). The X-Y configuration is entirely mono-compatible because there are no timing differences between the two channels.

A very robust and latching connector commonly used to carry balanced audio signals such as the outputs from microphones or line-level devices. An XLR is a type of connector developed by US manufacturer, Cannon, and used widely in professional audio systems. The company’s original X-series connector was improved with the addition of a latch (Cannon XL) and a more flexible rubber compound surrounding the contacts to improve reliability (Cannon XLR). The connector format is now is available in numerous configurations, from many different manufacturers, and with several different pin configurations. Standard balanced audio interfaces — analogue and digital — use three-pin XLRs with the screen on pin 1, the ‘hot’ signal on pin 2 and the ‘cold’ signal on pin 3.

Yamaha's alternative to Roland's GS system for enhancing the General MIDI protocol so as to provide additional banks of patches and further editing facilities.

The acronym stands for 'Serial Advanced Technology Attachment' and is a computer interface employed for connecting standard ATA hard drives to a computer motherboard. The SATA interface supersedes the PATA (parallel ATA) interface which has been used since the 1980s. A variant of the SATA interface, called eSATA (with the 'e' standing for 'external'), permits the connection of external hard drives. It uses a slightly different connector but is otherwise a very similar interface.

An electronic circuit capable of generating a control signal which represents the envelope of the sound you want to recreate. This may then be used to control the amplitude of an oscillator or other sound source, though envelopes may also be used to control filter or modulation settings. The most common example is the ADSR generator.

The way in which the amplitude of a sound signal varies over time.

An audio processor designed to brighten audio material using techniques such as dynamic equalisation, phase shifting and harmonic generation.

A system that modifies a signal prior to recording or transmission, and subsequently restores the signal on playback or reception.