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THE ARCAM ALPHA 10 DAB TUNER
Reviewed by Alan Stokes
From my early teenage years, rather longer ago than I care to remember, I have been an avid radio listener. At the beginning I used an old Ferguson valve FM radio that my father had discarded. It was mono of course, but that's all there was. The scale only went to about 100MHz - enough for what was broadcast, plus a few Police channels if that's what you wanted.
In the mid to late '60s VHF/FM stereo was introduced to the Third Programme (later Radio 3) and the other networks in October 1973.
In 1968 I began a long struggle to get 'quiet' FM reception. BBC Radio 3 and Radio 4 were my main stations and along the way a number of different tuners and aerials were tried in an attempt to listen to the content rather than the hiss, birdies and crackle that seemed to be a fact of life.
I live in a corner of Kingston upon Thames, in Surrey, which is in the shadow of Kingston Hill, making reception from the main SE England transmitter at Wrotham, in Kent, a little 'iffy'. Apart from a relatively low signal level, there's also "multipath" - reflected signals from the hill, which, when added to the original direct signal, don't exactly help - sibilents which sound like sandpaper being rubbed are one example. In television terms this is the equivalent of multiple images on the screen (I get that as well!) A more recent transmitter at Crystal Palace helped here but it suffered more with birdies from computer and pirate stations.
Thirty years on, I have tried tuners by Ferguson, Quad (the nicest sounding but not very sensitive for it's day) and various others. My latest is the Hitachi FT5500, jolly good at signal handling but still not that 'perfection' I was after. As for aerials, well you name it and I've probably had it - except the 'Galaxy' from Ron Smith, maybe. Finally I have a home built unit, built very carefully from a design by the BBC Research Department, though even that has a head-amp on it's output.
EARLY DAB
Back in the early '90s, I heard a demonstration, given in a television studio control room, of DAB (an EBU agreed system for Digital Audio Broadcasting). The feeling I had was similar to the first time I heard a CD player - within minutes, possibly even seconds, I was convinced that I wanted it! I could listen to the music, or whatever, and not be disturbed by all the 'additional' items.
Then began a long trail of, "When will it be available domestically?" and announcements that DAB would be available "soon... I knew that there were some demonstrations of car sets going on at various professional events so somebody was making receivers, and eventually the BBC announced a service beginning in, I think, September 1995. But how could I get a receiver? Having a contact, via a colleague, at the BBC Research Department, didn't work. A local car radio dealer advertised that they were the first, and then only, DAB retailer in the London area. They carried a Grundig unit which I asked to hear demonstrated. It was wonderful, even on car radio 'speakers. Then of course came the price, "About £2,500 sir." For that price they could certainly call me "Sir!" That sort of money was out of the question, especially as I really wanted a domestic unit.
FINALLY...
Finally, last year, Arcam announced that they were developing a unit, using a module developed by Roke Manor Research. Immediately I was in touch with my local dealer but was told, "Not yet." There were even prototype models at a couple of Hi-Fi and Audio-Visual exhibitions last Autumn. Arcam announced first production around November with full production in January 1999. Those dates came and went and I e-mailed the company and was told that they wanted to make sure there were no problems before releasing units. Quite right but not doing my frustration any good. (Couldn't digital terrestrial television receiver manufacturers learn a lesson here?).
Finally, on 20th April, Sevenoaks HiFi in Kingston rang to say they'd got a box for me. Even though I had to go off to work about 90 minutes later, I was out like a shot. They told me I was one of the first twenty in the country to have one so, according to the enclosed literature, I am a 'trailblazer'.
So, to the unit itself - stylistically, it matches the
current range of Arcam equipment. The box is bigger than an average FM tuner at
430x310x100mm. The front panel, from L to R, has a row of four buttons:
Then there is a large rotary knob, used for 'tuning' the stations. To the right of this is a dot-matrix display, two lines deep, below which are seven buttons for storing favourite stations. Each button has a small LED above it, showing which has been pressed. Finally, to the right of the display, is a bypass switch, so that a normal FM tuner, or whatever, can be used when DAB is not in use, without tying up another amplifier input. Then a volume control, which works with the headphone socket alongside. Finally comes the 'Power' switch. The handbook says that this switch only de-powers the RF and digital circuitry, leaving the analogue circuits powered all the time the mains is connected, to optimise sonic performance.
The rear panel has all the expected facilities
Beware, the aerial input is a BNC socket so make sure you have a plug to hand when installing. Otherwise, more frustration!. Incidentally, the digital outputs include SCMS (Serial Copy Management System) which allows one digital recording generation only. Further copies will be inhibited. There is also a small switch called Data Service Switch. This is used to prevent data (text etc.) from getting to the display. Well that's what the book says I guess this is for when Teletext comes to DAB! There is also an RDI Out socket, another output that "...may allow future expansion to use data services via an outboard device such as a computer..." (RDI = Radio Data Interface) There is a remote control, which clearly is designed to work with a whole range of Arcam products. Select DAB before use with this tuner and all is well. It then offers all the facilities available on the front panel, except headphone volume control.
INSTALLATION
Getting going was simplicity itself. Arcam suggest trying an existing FM Band II aerial, if one is already installed. However, since the currently available signals are in Band III (where ITV used to be in 405-line days) a new installation would best be a correctly tuned aerial, vertically polarised. The unit can also use signals in L Band (1452-1492MHz) if, where and when these are available. Fitting a BNC plug to the aerial was really the most complicated part of my installation. (What a shame so many people took their old Band III aerials down!)
The Alpha 10 comes pre-tuned to the BBC ensemble at 225.648MHz. In the London area at least, DigitalOne are radiating test signals so it's worth setting the receiver to 'search' before going much further. This is done by selecting 'Store/Search' followed by 'Select'. This takes up to 3 minutes.
From now on it's matter of gently rotating the big knob until the required service is displayed and then pressing 'Select'. To store a favourite, press 'Store Search' followed by the required button. From then on you can enjoy what, to all intents and purposes, is a connection to the studio. Well, almost... If you happen to drop into a channel with a pause in its audio, like Radio 3 or 4, don't raise the volume until the noise is apparent, as I might have with analogue, you will do damage! It's gloriously quiet and the 'programme' hasn't any distractions.
The audio signal, once in the digital domain, has data reduction applied, using the MUSICAM system, so there will be those who say it has a built in disadvantage. I would say to them, try it before condemning it. Existing FM transmissions have a restricted bandwidth, the upper limit being around 15KHz, so there are already compromises.
DAB - or Digital Radio as it is now to be known - is a joy to listen to. Certain sections of the HiFi press have started to 'knock' the system but, in my experience, it is better than anything that has gone before. It's quiet, has good imaging, good transients and lays bare all the faults in the source material! Listen to a well balanced live concert, however, and all the best qualities will be apparent. There's an added bonus - the Radio 3 feed is free of the dynamics processing which is applied to the analogue services. The aforementioned well balanced live concert, and the records of course, have a much more natural dynamic. A very enjoyable experience.
Classic FM are still on test and I can therefore forgive them that their output is still compressed. They have been inviting reception reports, so I did. I also took the opportunity to add a plea, to PLEASE, PLEASE remove the compressor, at least from the DAB output. So, maybe, just maybe...
The display has a number of uses. Initially it shows the station name and a 'static' description of the service. This can change, depending on what programme is running. On Radio 3 it currently shows "Serious Classical" but changes to "Drama" when a play is broadcast. With a press of the "Display Mode" button, it gives a scrolling display. Radio 3 use it to describe what's on, a title and orchestra for example. BBC World Service is running a test which shows news headlines and sports news. R4 usually shows the programme title and a few words about it. Further pressing of display mode shows the data rate in use or the signal 'quality'. I'm not sure how this grades quality but mine is at full-scale all the time!
With various button combinations the display changes from User Mode to Engineering Mode when signal strength is shown. There is also 'Ensemble Frequency'; 'Data Rate'; 'Transmitter ID' and 'Error Rate' (a count of up to 200 is possible before audio problems arise, according to Arcam. I'm running at between 1 and 3, following a small tweak of my aerial). As described, the DAB system can benefit from multiple signals from different transmitters, thus there is no need to operate a network of stations on different frequencies, they can all be the same. The 'Transmitter ID' display here is showing that I am receiving three, probably Crystal Palace, Reigate and one other. The commercial multiplexes are only showing one transmitter each.
WHAT'S ON
As for the available services, it's a little changeable at the moment. The BBC National ensemble is fairly consistent:
However, DAB has a facility for 'Secondary Services'. These might be used for specific sporting events, or national events maybe. They are usually associated with main services and show on the Arcam display as, for example BBC R4 Digital >>, the >> indicating a secondary service. The only way of accessing this is by a right turn of the big knob on the front panel. They cannot be stored, which may be deliberate as, when the service disappears, the store 'forgets' the service and doesn't remember it when the service returns. As I write this, a Monday afternoon in late April, Radio 4 has BBC Parliament as a secondary service and Radio 5 Live currently has Sport Xtra which is a promotion for the extra sport commentaries that are possible. It may be worth mentioning here that seven buttons for storing favourites may be a bit limiting, given the number of main services that are in the pipeline
Whatever else, the number of services on any ensemble has to exist within the 'bandwidth' of that multiplex. So, if more services are used, others may have to reduce their data rate to accommodate. The higher the data rate the better potential quality. Currently Radios 1, 2, 3 & 4 are running at 192Kb/s, Radio 5 is at 96Kb/s (in mono so that's half of 192). World Service are at 80Kb/s (mono). It looks as though the BBC are looking to see if a lower data rate can be used as there's a BBC Test with Radio 2 at 160Kb/s. It doesn't sound too bad but the audio is very compressed anyway!
DigitalOne is the first national commercial multiplex. Of the seven services available there, only one is currently in use, by Classic FM, on test. The rest have birdsong and countryside noises.
Also running, as I write, is a local ensemble carrying
I understand that this ensemble is currently running on an RSL (Restricted Service Licence) prior to a full announcement on operators.
The Arcam Alpha 10 costs £799.95. Only you can judge whether you can justify this sort of price. In time it is certain that costs will come down, you only have to look at how CD began to see this.
Other tuners are claimed to available, from Cymbol who were supposed to be in full production last Autumn but has anyone seen or used one, and at what cost? Also, Meridian are producing an add-on for their FM tuner but, again, cost is not known. My dealer tells me this is even more expensive than the Arcam. How will it 'add-on'?
So, is the Arcam worth it? My answer is yes. In domestic terms it is very new technology and that will always come at a price. But the audio quality is first class and I no longer need to make sure my PC is turned off or my satellite TV receiver completely de-powered, to avoid birdies and I no longer suffer with interference from weekend 'pirates'.
Review: The Psion Wavefinder
Other related sites:
Arcam
| Alpha 10 Digital Tuner
BBC Guide to Digital Radio
BBC DAB Transmitters
NTL DAB
British DX Club DAB
Transmitter lists
The World Forum for Digital Audio Broadcasting
DAB Online Information System
The DAB Directory
Ted Ledingham's Digital Radio site and the RADIO-L
mailing list
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