When the length of an electrical cable is shorter than about 10% of the wavelength of the signal it conveys, the voltage and current are effectively the same at all points along the cable. However, if the cable is longer than 10% of the wavelength, the signal can be considered to propogate as electromagnetic waves along the cable, and this condition is referred to as a 'transmission-line'.

A bi-directional computer interface based on the PCI Express protocol, used for both data transfers and to connect display monitors (it supports DVI, HDMI, and VGA monitors via adapters). Introduced by Apple in 2011.

A term first used in the 1980s to describe early ‘tapeless’ recording/sampling machines like the Fairlight and Synclavier. Nowadays, DAW is more commonly used to describe Audio+MIDI ‘virtual studio’ software programs such as Cubase, Logic Pro, Digital Performer, Studio One and such-like. Essentially elaborate software running on a bespoke or generic computer platform which is designed to replicate the processes involved in recording, replaying, mixing and processing real or virtual audio signals. Many modern DAWs incorporate MIDI sequencing facilities as well as audio manipulation, a range of effects and sound generation.

The form of electrical current supplied by batteries and the power supplies inside electrical equipment. The current flows in one direction only.

— see dB

A form of adapter cable that passively splits the output of a source to feed two or more destinations. Y-leads may also be used in unbalanced console insert points, in which case a stereo jack plug at one end of the lead is split into two monos at the other for separate send and return connections. A Y-lead must never be used to combine signals.

The parameter of tape head alignment relating to vertical alignment head and whether it is leaning forward or back relative to the tape path. (cf. Azimuth and Wrap.)

The point at which a signal waveform crosses from being positive to negative or vice versa.