Eight Channel Parametric Equaliser (PEQ) and Mixer Unit for the Calrec "J" Series sound desk installed at Millbank by the BBC for broadcasting from the House of Commons.

Proposals for live coverage from the House of Commons were first discussed by Parliament in 1964. Following test transmissions in 1975 this equipment was part of the permanent installation made by the BBC in 1978 to broadcast live radio coverage. Broadcasts were made on Radio 4 and clips included in review programmes such as Today in Parliament. Television coverage was introduced in 1989 and from 1998 broadcast as BBC Parliament.

The Calrec "J" series sound desk was designed for the BBC. Large numbers were produced and it was used extensively for outside broadcast and on location recordings.

The "J" Series came in modules comprising eight channels, eight stereo groups and auxiliaries, and an output unit with monitoring and metering which were hooked together with multicores. Up to 72 channels could be cascaded to make a very large sound desk that still was managable for transport. Each unit had built-in carrying handles and could be lifted by one person. Modules could be hot-swapped to extend the required number of inputs whilst broadcasting without causing thumps on the output.

This channel mixer unit is an example of the flexible expansion units that could be used to increase the capacity of the desk. Channel 5 is labelled ‘Tannoy’ which would have taken a direct sound feed from the House of Commons internal tannoy.