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Audio From Video

Sony Hi-Fi Beta Recorder

Following on from last month's article on the principles of Hi-Fi video recording, Carl Anthony takes a look at Sony's Beta Hi-Fi machine, the SL-HF100.

Although it has been around for sometime in America and Japan, it is only recently that Beta Hi-Fi has been available here in the UK. The reasons for this have been largely due to technical considerations which we will look at later in the review.

For the benefit of any new readers who are wondering why we are reviewing a video machine in a sound recording magazine, the Sony SL-HF100UB (or SL-HF100 for short) is one of a new generation of 'Hi-Fi Sound' video recorders. Basically, they can be used in one of three ways: (1) to record and playback video recordings with conventional, linear audio soundtracks; (2) to record and playback video tapes with a vastly improved Hi-Fi soundtrack obtained via the video head or (3) to record and playback audio-only recordings made via the video head. It is this last facility that is of interest.

Beta Hi-Fi recordings (and VHS Hi-Fi recordings for that matter) are not digital, nor are they similar (or compatible with) the Akai MG1212 video tape-based micro studio reviewed last month. In essence, the Sony SL-HF100 is a high-quality conventional video recorder with a very unconventional audio recording system. Anyone who needs a more detailed, technical explanation of this revolutionary recording process should check out the February issue.


The Sony SL-HF100 is extremely compact measuring only 430mm x 105mmx 380mm (w/h/d). Being only 430mm (17 inches) wide it would be possible to rack mount the recorder using additional brackets, but there are no fixing points provided for this purpose. Apart from the tuning controls, which are under a flap on the top of the unit (used for obtaining the various TV stations), all the major controls are on the front of the machine.

To the far left is a mains On/Standby switch, a headphone mini-jack, and a headphone level control. Next along is the loading flap for the video cassette with the illuminated transport controls underneath. These include, Play, Stop, Rewind, Fast Forward and Pause. Record and Eject are separate from the main bank of controls which is just as well as you only need to push the one Record button to go straight into record mode.

On the right-hand side, the top section contains the Left and Right Peak Level Meters (-40dB to +5dB), two gain controls and a switchable display unit. This contains a clock, tape counter, programme indicator and various information regarding recording times preset by using the built-in timer section.

Below these functions is a concealed flap which contains the timer controls and a set of six switches. These include the input selector (Line/Tuner/Simul); meter On/Off; a Video or Sound only record switch for the Hi-Fi circuit and High/Low tone switch. Also concealed under the flap is a rotary tracking control.

At the back of the machine are connections for a TV aerial (standard 75ohm type); BNC connectors for the Video In and Out signals; and two sets of sockets for Audio In and Out. Additionally, there is an RF Channel adjustment for tuning the recorder to a TV set, a six-pin DIN AV connector (audio and video together), a camera remote jack, a booster switch for TV signals and the main on/off power switch.

Setting Up

The Sony SL-HF100 comes with an infra-red remote control and a coaxial lead to connect the video machine to a TV (the main aerial lead goes directly into the Sony). The remote control has all the transport functions of the main machine (with the exception of Eject) and can also be used to turn the machine on and off and select TV channels. It can control the machine from a distance up to 7 metres (23 feet). It is powered by two R6 batteries and although the function switches don't light up, a small red LED lights momentarily whenever a button is pressed.

In order to start recording, two sets of phono leads will be needed. These are connected in exactly the same way that you would connect a cassette deck or reel-to-reel machine.

At the rear of the machine is a mains On/Off switch. This is usually left on so that the clock is displayed and the video head is kept warm. Video machines are quite susceptible to condensation and playing a tape, taken from a warm room, on a machine stored in an uninsulated loft or garage studio, can cause a fair amount of damage as condensation forms between the warm and cold surfaces. As the heads rotate at 1500rpm there's not much time to stop the machine if the tape starts to stick to the heads or tape guides. In practice, the machines are reasonably tolerant but don't push your luck if the weather is a bit on the nippy side. Very cold tapes or machines should be allowed to warm up gradually.

After pressing the front panel 'On' switch a video cassette can be loaded. For those of you not familiar with video, there are two different systems - VHS and Beta. Although they both use ½inch tape, the cassettes themselves are different sizes and thus not interchangeable. Beta tapes are smaller though the playing times are similar: 125 (30mins); 250 (65mins); 500 (130mins) and 750 (215mins).

Loading is simplicity itself. The cassette is just pressed against the loading flap. Weird and wonderful noises draw the cassette into the machine and lace up the tape automatically, whereupon an orange indicator light tells you that the machine is loaded. As the recorder is black and there is no illumination within the cassette compartment (which is a pity) the warning light is quite useful. Without this feature you could be tempted to try and jam a second cassette into the loading bay with disastrous results.

At this point in the proceedings the machine will have well and truly come to life. The logo 'Prog 1' will be illuminated in the display panel, along with the clock and the day of the week. 'Prog 1' indicates the TV station you're tuned to (there are 12 in all). Selecting the Line input automatically extinguishes the channel number replacing it with the letters 'Au'.

The meter display can be switched off. When the display is on, two green LEDs marked with an infinity symbol remain on. These are peak-reading meters scaled as follows: -40; -30; -20; -15; blank; 13; blank; -3; 0; +2; +5. Zero and above are red LEDs, the remaining nine are green. The instructions recommend a recording level peaking at '0' and averaging out round about the beta sign (probably -7 of the missing sequence -10; -7; -5). The meters are easy to follow with respect to their ballistics but yellow segments for the average levels or an illuminated dB scale would have proved more useful if sitting away from the machine or using the remote control.

Two pushbuttons under the main display can be used to select either the clock or the tape counter. The tape counter, although displayed in a clock-type arrangement (ie. 00 00), doesn't actually count real time. For example, the display 01 38 only means 138 units not 1hour 38mins. It's a real pity it wasn't real time as I can't imagine the relevant chip would cost that much more. At the end of the day video I suppose, is a competitive business and a few bob saved here and there can make all the difference.

Record level is varied with independent horizontal sliders. Although a little small, they are reasonably easy to use for stereo fades though they can be a bit awkward when it comes to setting individual right and left levels if the input signal is slightly out of balance. Indication that you are making or replaying a Hi-Fi tape is shown by an illuminated green rectangular Beta Hi-Fi logo. This remains on unless you are playing conventional tapes. Switching the machine to 'sound-only' status will illuminate a green LED next to the Hi-Fi logo. Once you become familiar with all the indicators, it is very easy to check whether or not you have the machine set up correctly.


Before we move on to the recordings themselves one quick word about PAL (no jokes please). Throughout the world there are different standards for television broadcasts. As far as colour transmissions are concerned there are three main types. In the UK and most of Europe the standard system is PAL (Phase Alteration Line). France has a separate system - SECAM (Sequential Colour with Memory), and Japan and USA have a system called NTSC (National Television Standards Committee). If you have ever seen American television you'll know why it is sometimes called - Never The Same Colour!

The point of all this is that all the systems are incompatible and that applies to video recordings as well. But what about sound-only recordings, surely they can be played on American machines? Unfortunately, the answer is no. Due to the nature of the American system the Hi-Fi signals can be recorded by the video head. The depth technique used in the UK PAL system requires separate audio heads thus making the two recording techniques totally different. Should you be thinking of swapping tapes or buying a machine in the States bear this in mind.

Sound Quality

Although the Beta cassette uses ½inch tape it is asking too much to expect 30ips ½inch reel-to-reel quality - the sound, however, is excellent. Making comparisons with a high quality cassette deck - Aiwa - and metal tape, the Sony won hands down. There is much better stereo separation, a tighter more stable stereo image and less audible distortion, especially at the bottom-end. For the long suffering home recordist, however, the overall lack of background hiss will be a real treat. At high domestic replay levels there is none of that all too familiar tell-tale hiss preceding each track.

At the top end of the frequency range the sound is a little on the bright side, but in a way I didn't feel this was necessarily a bad thing. It tended to increase the projection of the sound without introducing any nasty side effects and I would imagine this could well be an advantage for many home studio productions.


Given that this is primarily a video recorder, the sound quality is truly a bonus. On the pre-recorded videos I sampled, the Hi-Fi sound was quite breathtaking compared with what now seems old-fashioned and out-dated mono TV reproduction.

As a mastering machine, the Sony SL-HF100 can do all a cassette deck can do - and do it better. As for reel-to-reel, the situation is a little different. First, you don't have access to the tape so editing is out of the question. So are drop-ins and track bouncing (left/right) though you could use the SL-HF100 to dump stereo mixes (such as rhythm tracks) at the start of a multitrack session in order to keep the noise levels down.

The system as it stands has great potential. With a home computer editing system (already in the pipeline for video editing on domestic machines) you could really go to town. This, for example, coupled with the transport of the Sony C9 video recorder (which has slow motion and single frame advance) could form an excellent basis for an audio machine. Or even a total component system, with separate transport, editing, video and audio modules which you could build up as you needed them, might be the answer. As things stand at the moment, this is a video development to improve the poor quality of video sound: it would be a pity to just let matters rest there.

If you are in the market for a video recorder that can be used for prerecorded films, making your own videos, or if you want to record simulcast concerts in glorious stereo, at £599.95 the Sony SL-HF100 is an excellent purchase. With a buckshee tape recorder thrown in, every home should have one!

Sony SL-HF100UB Specification

Audio recording system:
Beta Hi-Fi stereo, helical scanning AFM.
Normal mono, conventional linear track.
Input (Audio) -10dB 47 kilohms.
Output (Audio) unbalanced, less than 47 kilohms impedance.
Frequency response (Beta Hi-Fi) 20Hz—20kHz.
Wow & flutter less than 0.005%.
Dynamic range more than 80dB.
Power requirements 240Vac 10% 50/60Hz.
Power consumption 36W.
Operating temperature 5°C to 40°C.
Weight approx. 10.5kg (23lbs 2oz).

Previous Article in this issue

Interfacing The Line

Next article in this issue

Readers' Tapes

Home & Studio Recording - Copyright: Music Maker Publications (UK), Future Publishing.


Home & Studio Recording - Mar 1985

Donated & scanned by: Mike Gorman

Gear in this article:

Video Deck > Sony > SL-HF100 Beta

Review by Carl Anthony

Previous article in this issue:

> Interfacing The Line

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> Readers' Tapes

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