(Reprinted from issue 61 of UHF Magazine. To purchase the issue, click here. Or click here to subscribe to UHF)

Cambridge Isomagic Converter

If it looks like an antivibration platform, that's because it is. But it's also a high end component.

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There's almost no way around this: the lower the selling price of a product, the fewer the choices open to its designer. More and more high end companies are completing their lineups with "democratic" (read: cheap) units, which sound nothing like other members of the family. And how could they? Price constraints forced their designers to make them almost exactly like the competition's.
     But you can leave Cambridge Audio out of this generalization. The reason we've been recommending some low-cost Cambridge products, including its CD players (see the D500 in UHF No. 59), is that the designers have made a special effort to beat the cost-price squeeze. They still must make choices, but they're different choices, and at least in some cases the results have been particularly felicitous.
     However, no other Cambridge product has ever been as unusual as the S700 Isomagic. It doesn't look like anything you've seen from the competition, and the sound...
     But all in good time.
     The Isomagic is of course a DAC: a digital-to-analog converter. Though DAC's appear to be an endangered species, rapidly losing ground to one-box players, a few manufacturers are swimming against the current. And Cambridge still does make a transport, the DiscMagic (reviewed in UHF No. 50).
     But the fact that it's a DAC isn't what makes it unusual. Check out the shape. We know (though some manufacturers and magazine editors clearly do not) that digital sources, like analog sources, are sensitive to vibration. Many audiophiles use special tables, or isolation devices such as cones or (for instance) Isobearings. With the S700 you get the platform along with the DAC. It sits on five cute little rubber balls, and you put the transport on top. Competitors? What competitors?
     The Isomagic isn't very tall, if you don't count the balls, but it's wide, and in particular it is unusually deep. It needs to be in order to accommodate even a large CD transport, but it takes up a lot of space, more than some equipment tables provide. And it actually requires more elbow room than a standalone isolation platform would, because the connectors are on the back, and you need to leave space for them.
     At the rear are the coaxial and TOSLINK digital inputs, and also a TOSLINK clock link. That link is meant to plug into the matching clock connector on the DiscMagic transport. This connection, originated by Linn and Spectral, as far as we know, is now at the heart of a number of players, though not usually ones this low in cost. The purpose of the circuit is to allow the DAC to determine timing, by telling the transport when to send the next sample. This of course works only if you have a Cambridge transport. We wished the connection could be made with a coaxial lead rather than with the often problematic plastic optical fibre.
      Also at the rear is the round socket for the Isomagic's outboard "brick" power supply.
     Underneath the Isomagic's steel bottom plate are eight indentations for the rubber balls, which Cambridge calls "Puds." Only five Puds are supplied -- one for each corner, plus one for whichever side needs extra support once you put the transport on top. Each Pud has the company logo on it, but if you feel as though you're being stared at, just turn them the other way.

     After the obligatory break-in period, we carefully placed our Parasound transport on top and dug out a small pile of discs. Nearly all the discs were encoded in HDCD, because the Isomagic does have Pacific Microsonics' HDCD chip aboard.
     The first of our recordings is also our most challenging, and it gives trouble to even expensive players. It's Richard Strauss's overblown and over-orchestrated Ein Heldenleben. Any symphonic instruments Strauss didn't use in this tone poem, nobody needs. The result is a mass of sound that has been used on demo records for 70 years, even though it's nearly impossible to reproduce.
     Well, it still sounded somewhat confused with the Isomagic, as it does with virtually all players but the two Linns (CD-12 and Ikemi), and it had lost a bit of the bottom end weight that is captured on this Reference Recordings disc (RR-83CD), but it sounded amazingly good just the same. Timbres were mostly plausible (except for the massed strings, which at times sounded like whistles, as they had with the Linn Genki). Reine found the trumpets a little shrill too, but our combined notes mostly contained compliments. The Isomagic had tackled a nearly impossible recording and at least saved its honor.
     From there things could only get easier, though our next recording presented a challenge too. It was the Stravinsky Firebird (Reference Recordings RR-70CD), whose wide dynamic range includes difficulties at both extremes.
     The Isomagic did very well. In the very soft passages, Stravinsky's evocative magic was largely intact, with no mist to hide the details. The harp arpeggio was gorgeous, and the orchestra built with strong mood and good emotional tension. This time the strings were just right. The brass was a bit brighter than with our reference, but not objectionably so. Albert would have liked more bottom end punch, though the famous bass drum had plenty of it. Reine noted that its booming sound seemed to go on and on...too long, thought Gerard. Depth was very good.
     The third recording would be an excellent test for reproduction of depth...as well as for solidity of lows and smoothness of highs. It was the HDCD version of Antiphone Blues (First Impressions Music CD003). We've heard this recording massacred, but nothing bad happened to it this time. Arne Domnérus's saxophone was clean yet detailed, with exemplary smoothness. The organ perhaps had less weight than it had with our reference, but it was satisfactory, and indeed it was better than with most players we've heard. The recording's famous depth (it was recorded in a large church) was largely intact.
     It's a constant pleasure to return to the wonderful Comes Love (Opus 3 CD19703), with its felicitous blend of piano, trumpet, clarinet and sousaphone. The bottom end may have been a little lighter than usual -- it showed up on the sousaphone -- but the pleasure was otherwise undiminished. The piano tone was both attractive and realistic, but it was the clarinet that drew the most comments. It was sensuous and expressive as it climbed up the scale, sounding at times like a human voice. Rhythm was strong and clear. "Nothing's missing," concluded Albert.
     Nor was much missing from You Can't Take my Blues (Audioquest AQCD1041), in which once again the rhythm -- often messed up by CD players -- remained powerful. Doug McLeod's voice was clear and smooth, with even his trailing syllables perfectly audible. Indeed, we could hear a slight reverberation following each of those final syllables...a sign of the Isomagic's way with fine details. The percussion was very good. Even the cymbal sounded excellent, if not quite the way it is with our reference. Cymbals are notoriously hard to reproduce, and CD players have as much problem with them as loudspeakers do.
     We wanted to include some female voice, and we chose Amanda McBroom's Gossamer (found on the discontinued West of Oz as well as the newer Amanda Gold). We were impressed. Her voice was smooth and about as natural as it can get. Her sometimes prominent esses were superbly natural. We noted approvingly the fine timbre of both the piano and the bass. "This is a reliable converter," said Albert. "It sometimes commits a sin of omission, but never of commission."
     We could easily have stopped there, but we added a second female voice, that of Lori Lieberman in Killing Me Softly (from A Thousand Dreams, Pope PM2001-2). We liked it. Her voice was very slightly harder than with our reference, the sibilance a touch less natural, but none of this got in the way of the song's emotional delivery. We were smiling wistfully as it ended.
     In an earlier session we had used the very demanding version of Vivaldi's Four Seasons by Fabio Biondi and his ensemble (Opus 111 OPS 56-9120), and we wondered how the Cambridge would cope with its bright closely-recorded strings. It did quite well, in fact. It did sound a little close (since that's the way it was recorded), but no more than it had with our reference. Albert pronounced it acceptable.
     We took the converter into the lab, and confirmed a minor problem we had noted by ear: a mysterious whistle -- too low to be objectionable in listening to actual music, but enough we could hear it if we turned up the volume. We don't know the cause, though we can pretty much suppose it's a sample defect. We should add that we often see high frequency noise from power supplies showing up on this test -- even the wonderful Linn Ikemi had some -- but of course it should always remain inaudible.

     The 100 Hz square wave (below) came through very well, with minimal ringing, well damped. As usual we looked at the oscilloscope image of a low-level signal, a 1 kHz sine wave 60 decibels below full level. As you can see on the previous page, it is heavily contaminated by the whistle we mentioned. The source is probably in the power supply, and another sample would probably look quite a lot better on this test.

     We had waited a long time to take this converter out for a spin, since there was a long gap between its announcement and its actual production. It was worth the wait. Of course, the fact that it had HDCD decoding had piqued our interest, but bitter experience has taught us that the presence of the HDCD logo does not always guarantee a pleasant or even an acceptable listening experience. In this case it was pleasant and far more than just acceptable. Adding it to your existing CD player could be the smartest upgrade you can make. Take your player along, and go hear it. You may be as pleased as we were.

Model: Cambridge Isomagic S700
Price: C$1000/US$600
Warranty: 2 years, transferable
Dimensions: 43 x 35 x 3 cm
Most liked: Pleasant musical performance, no bad habits
Least liked: Too deep for some equipment tables
Verdict: HDCD made both desirable and affordable


     Listening to a series of recordings with this converter, I discovered its considerable qualities, and even a certain magic. Depth and image are more than adequate. Timbres are attractive, and both male and female voices are natural and pleasant. The sax, the clarinet and the piano all sound good. I need only list its qualities to evoke the pleasure I had from the listening session: rhythm, depth, natural timbres, sensuality, a good dynamic range, emotion, lyricism. All of this is reproduced for our great pleasure.
     I would go as far as to say that if you can improve your system by adding a quality converter at such a low price, you shouldn't hesitate. Can I add more? As a bonus, this excellent converter is also a platform on which your transport will feel at ease.
--Reine Lessard

     This converter, in a subtle way, made me forget about the reference. I did notice a certain lightness in the lower bass, at first, but then I stopped comparing and the music settled comfortably into known territory.
     I found the same qualities in the overall texture of the music -- whether I concentrated on massed strings or individual voices. I had to remind myself from time to time that it wasn't the reference playing, and I wondered how different the music would actually sound. When I start asking myself those questions, it's time to admit that this converter is a surprising value.
     All I kept thinking of was, "Gee, that was pretty good." One piece followed another and I found the sense of space I knew so well, the magic of whispering strings, the subtle woody timbre of the clarinet, the lovely rendition of voices and the clarity of lyrics and, throughout, this great sense of rhythm.
     And you know what? All of it sounded really, really good. Knowing the reference sound, I was surprised. Knowing Cambridge, I shouldn't have been.
--Albert Simon

     Considering the price of this converter, you expect it to be a little less good than others on a number of items. You expect slightly lighter bass, a slightly shallower image, slightly rougher highs. Well, I got that much. You also expect a slight mist that hides details, a slight shrillness, a little less of the excitement of real music. And that I didn't get.
     How is it done? Well, the chip sets available to designers have been getting both better and cheaper. The companies that don't care about sound are using them to turn out the same old, same old. The ones that do care are waking up to the possibilities.
     Put Cambridge in the second group.
--Gerard Rejskind

(This is a complete review from UHF issue No. 61. To read other reviews and articles in full, just order issue 61 at our secure server.)

Complete articles from this issue:
The Battle of the Super Discs, Cambridge Isomagic Converter, Soundcare Superspikes, State of the Art

Excerpted articles from this issue:
New Surround Formats, Defeating DVD Zoning, Vegas 2001, Audiomat Tempo & Vecteur D-2, Audio Refinement Pre 5 Preamp, Osborn Mini Tower Speakers, Mirage OM-9 Speakers