In August E&MM visited Harrogate for this year's International Festival of Sound and Video.

The main emphasis this year was on Digital Audio with prototypes on display from most of the large manufacturers of audio equipment.

You might think that when the Compact Disc arrives your current record and/or tape collection will be obsolete. However, most of the exhibitors view the digital disc as merely another option to add to your turntable, tape or tuner inputs. Eventually, it may be accepted as the standard medium for home, car or personal Hi-Fi, but with the current advances in Audio and Visual electronics, who knows?

For the time being, however, here is a selection of the new equipment and developments which were on show.

DBX

The dbx 21, when used with one of dbx's large range of encoded discs, provides reproduction with increased dynamic range and virtually no record surface noise. The dbx disc contains signals compressed before recording which when decoded by the dbx 21 (or one of the standard dbx type II tape noise reduction systems) increases the dynamic range of a standard record pressing from 50dB to around 90dB! A large, and ever increasing, range of record titles is available.

MORDAUNT SHORT

The MS20 is derived from the company's Carnival 3 with the same drive units and comparable specifications but designed to be driven by smaller systems. With a rating of 10-80 watts, frequency response of 80-20kHz ±3dB and a very pleasant sound, at around £90 a pair, they represent very good value for money.

ALPINE

Claimed to be 'One of the best cassette decks money can buy', the AL90 certainly has a lot to offer.

The most interesting feature is a microprocessor controlled 'BLES' system. This stands for Bias current Dolby Level and Equalization Search. When activated the deck automatically records three brief sections of 1kHz, 7kHz and 15kHz tones from an internal oscillator. The deck then adjusts the bias current followed by the Dolby level and Equalisation in 0.25dB steps. The process is repeated up to six times to find the setting which provides the flattest possible frequency response. This takes between 20 and 40 seconds during which time the 'OK' lamp indicates. This signifies that the response at the three frequency points are identical to a tolerance of ±1dB. If the points are identical to +3dB the light will flash, otherwise an 'ERROR' lamp lights, indicating substandard tape or the wrong tape selector position.

Four sets of calibration data can be entered into the memory and recalled every time the same tape type is used. There are also four factory pre sets for reference tapes.

The recording and playback circuits have separate power supplies for each channel to avoid channel-to-channel interference. The deck also contains Double Dolby systems, types B and C, three heads, three motors, recording meters switchable between Peak or VU, 4 digit tape/time counter and pitch control; even an optional rack mounting kit can be supplied. All in all a very impressive machine.

INKEL

This system has the capability of being totally under infra-red remote control. The hand-held unit, shown in front of the cassette deck, has 23 buttons allowing control of the following parameters; Record Deck: Reject and tonearm Up or Down; Tuner: Wavelength selection and 14 Station Memories; Amplifier: Input selection, and Volume; Cassette: Play, Record, Stop, FF, REW or Pause. The unit can be operated at distances of up to 20m. The complete system is retailed at £499 from Logica (Audio Video) Ltd.

WHARFEDALE

Wharfedale have introduced yet another new range of speakers, the 'Mach' series. The mid-range and bass drive units have been redesigned with ultra lightweight fibre cones, ceramic magnets and ventilated aluminium voice coils. The tweeters are compression driven loaded by horns which are designed to ensure a wide dispersion of sound. The speakers also have tone controls, LED metering and overload protection which can be reset from the front panel.

QUAD

Quad have introduced a new control unit, the Quad 34, dubbed 'the thinking man's pre-amp.' It is shown here with the Quad FM4 introduced earlier this year. It features CMOS solid-state switching selected by push-buttons with isolated inputs. Four types of top-cut filter characteristics can also be selected to remove distortion without removing musical information. Bass and 'Tilt' controls are provided to control the frequency characteristics of the unit. The Bass can be set to 'lift' (boost) bass or 'step' which acts as a step filter to prevent distortion of the bass caused by a speaker situated in the corner of a room. The 'Tilt' control adjusts the balance across the frequency spectrum. A disc input can be accurately matched with a series of plug-in disc input modules. The unit is priced at approx. £219, including VAT.

SENNHEISER

The SI406 has been developed to assist hard of hearing people who have difficulty listening to television or other audio devices.

Although this product is not of great use to the average reader it is an interesting application of current technology. The transmitter takes the input from a microphone and converts it into an infra-red signal. The user can pick up and decode the signal with a battery powered stethoscope headphone receiver, therefore adjusting the volume to his own level without bothering other listeners. A charger is also supplied for the rechargeable battery.

DIGITAL AUDIO

The most exciting products at the show this year had to be the Compact Disc players and PCM processors. Although these machines were all prototypes and will not be available until early next year, they will be worth waiting for — the sound quality is astounding. Each disc is 12cms in diameter, can play uninterrupted for 1 hour, and will cost at first around £8. The disc cannot wear out and complex error detection and correction circuitry in the players will allow for errors caused by dust and scratches on the playing surface.

The PCM processor is also an inspiring prospect. This allows you to record normal stereo analogue signals in digital on to a standard VCR, regardless of the format. In theory, you can have studio quality sound recording in your living room. Typical specifications for the digital processors are: Frequency response 5 Hz - 20 kHz, Signal to Noise ratio of more than 85dB, Dynamic Range of more than 85dB, Channel separation of more than 80dB, Total Harmonic distortion less than 0.01% and wow and flutter unmeasurable!

Next month in E&MM we will be taking a close look at the Digital Disc and PCM techniques.

Contact Addresses: Here are the addresses to contact if you would like to know more about any of these products. Please mention E&MM when doing so.

DBX (Contact Details).
Mordaunt Short (Contact Details).
Alpine (Contact Details).
Inkel (Contact Details).
Quad (Contact Details).
Revox (Contact Details).
Sennheiser (Contact Details).
Philips (Contact Details).
Sansui (Contact Details).
Fisher (Contact Details).