AUDIO NEWS

The Rogers Ravensbrook tuner-amplifier combines the well known 'separates'

Photo-micrograph of CBS SQ grooves showing front left and right modulation (top) and helical rear channel modulations 1971 Audio Fair bigger than ever

The 1971 International Audio Festival & Fair runs from October 25th to 30th and will be larger than ever before. Already the stand space allocated to exhibitors exceeds that of last year's event, and an additional floor of the Empire Hall at Olympia has been taken, giving a total exhibition area of 139,000 sq. ft. Among special attractions at the Fair will be a continuous series of lectures, presentations and film shows for audio enthusiasts and music lovers in a specially prepared hi-fl theatre.

Further information can be obtained from the organisers, International Audio Festival & Fair Limited, Dorset House, Stamford Street, London SE!, telephone 01-928 3333; or 42 Manchester Street, London Wl, telephone 01-486 2080.

Rogers introduce first tuner-amplifier

Rogers Developments (Electronics) Ltd. 4-14 Barmeston Road, London, SE6 3BN, who have manufactured separate amplifiers and tuners for many years, have just announced their first integrated tuner-amplifier.

The Ravensbrook tuner-amplifier is technically the same as the existing Ravensbrook 'separates' with the addition of an AC power outlet, a third speaker outlet for derived rear channel sound and manual override of the stereo decoder. New styling features front panels in either satin silver or brushed pale gold, control knobs in solid aluminium and an optional free-standing case finished in teak. The recommended UK retail prices with purchase tax at the new reduced rate are Chassis Model: L99-39, Case Model: L118.43.

The Ravensbrook semi-professional Stereo Headphones have also been announced. Particular features include a twin moving coil system, individual volume controls integral with each earpiece and light weight. The recommended UK retail price is L18.50.

"Audio 71" exhibitors list

The Northern International Hi-Fidelity Festival will take place at the Hotel Majestic, Harrogate, from 17th to 19th September 1971. A large number of firms will be exhibiting, with the following product names represented : Astec, Audio Development & Research, Audio-Technica, Arena, B 0, Binatone, BSR, Bose, Cambridge Audio, Celestion, Cosmocord, Garrard, Hitachi, Helme, Harman Kardon, Jordan Watts, Koss, Leak, Luxor, LNB, Metrosound, Mordaunt-Short, National, Ortofon, Pioneer, Peerless, Pickering, Polyplane, Precision Tapes, Richard Allan, Stereosound, Shure, Sonab, Stax, Sinclair, Sugden, Sanyo, Telefunken, Sansui, Schweizer, Tape Recorder Spares, Tandberg, Thorens, Wharfedale.

Purchase tax on speakers

Purchase tax is to be charged on certain types of speaker enclosures containing three or more speaker units. Hitherto all such enclosures have been exempt.

The new ruling, coming into operation on August 2nd, has been introduced by Customs and Excise following discussions with audio manufacturers and the trade. The intention is that exemption will apply only to equipment supplied solely for industrial and address systems.

When the original rules were introduced and exemption was given to three speaker enclosures, firms were able to add an inexpensive tweeter to existing two-unit assemblies in order to avoid paying tax. The new rulings are intended to plug that gap.

In future, an enclosure containing three or more speaker units will now be regarded as taxable unless it meets the following requirements: (1) the cabinet must be specialised and designed for wall or suspended mounting and be incapable of free-standing use, (2) a 100V line transformer must be fitted with external terminal connections and (3) the equipment must be advertised and supplied solely for industrial or public address systems.

The existing liability for tax on single or twin unit enclosures is not affected by the new ruling. and enclosures containing three or more units will not be subject to PT if any one of the speaker drive units is itself of the non-taxable cone type (12in. or over).

CBS demonstrate quadraphonic disc

The Columbia Broadcasting System, who developed the first commercial 331 rpm LP record, have produced a compatible "Stereo/ Quadraphonic" (SQ) gramophone record. It was demonstrated at the Montreux IMIC3 in June by Clive J. Davis, President of Columbia Records, who told delegates, "Quadraphonic sound reproduction will no wbe possible on present high fidelity home phonographs by the addition of a special decoder. another amplifier and two additional loudspeakers. This major electronic breakthrough was developed by CBS Laboratories under the specific commission of Columbia Records. Through a newly developed matrix, four channels of sound are converted into two and recorded on a disc record. On playback. the special decoder provides a reproduction of the original programme on four separate channels. Without the decoder, the programme will reproduce as stereo, thus allowing the new stereo/quadraphonic record to be played on all existing phonographs, providing for full compatibility as well as quadraphonic sound.

"To enhance and to prepare our basic invention for worldwide marketing, we have joined forces with the Sony Corporation.

"Columbia Records [USA] plans to release 50 titles before the end of the year, in addition to introducing a quadraphonic unit in its Masterwork phonograph line. Because there are higher costs involved, and because not all material will be released in quadraphonic, the new, compatible stereo/quadraphonic recordings. abbreviated "SQ:', will be marketed as a separate line and at a suggested one dollar higher list price than that of our conventional stereo LP".

Dual move

As from Monday, June 28th 1971, Dual Electronics Ltd., are operating from new premises at Clive House, Queens Road, Weybridge, Surrey.

Servicing and spare parts are being retained at St. Georgen House, Stokenchurch, Bucks.