London Reference Phono Cartridge

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London Reference
London Reference Phono Cartridge

The london (formerly “Decca” or “Decca London”) cartridge has the longest and most distinguished pedigree of any piece of phonographic gear currently on the market. It has been around in one form or another since before the stereo era—the result of some extraordinarily ingenious and enduring engineering by the Special Products group of the Decca Record Company. (The current London Reference cartridge has no connection to Decca Radio & TV Ltd., which sold the rights to the cartridge’s design and manufacture to former Decca engineer John Wright and Presence Audio in 1989.)

What sets, and has always set, Decca cartridges apart is the way they generate sound. All phono cartridges convert the physical motion of a stylus into an electrical signal. Most use a cantilever—a long thin metal tube equipped with a flexible rubber ring that acts as a fulcrum—to transmit the vibrations from the stylus at one end to the moving magnets or coils at the other. It was Decca’s contention that the resonances of the cantilever, the damping effect of the rubber fulcrum, and the sheer mass of the magnetic engine at the far end of this virtual “see-saw” caused losses of clarity and dynamic range—what Decca called “cantilever haze.” To sidestep these problems Decca came up with a cartridge without a cantilever.

Here’s how it works. A diamond stylus is mounted at the tip of a small flexible piece of slightly angled iron, which, in turn, is glued at its rear to a rubber block (to keep it centered) and further held in place by a tie-back cord (to prevent the angled-iron armature from moving forward).

The armature is then situated directly within the magnetic field, with the magnet and coils that generate the signal from vertical modulations of the stylus immediately above it and those that generate the signal for horizontal modulations of the stylus immediately to its sides. The iron armature is magnetized by these stationary magnets, and its movement causes lines of magnetic flux to cut through the coils, inducing a voltage (a variation on the moving-iron or induced-magnet design). Decca called this system “positive scanning.” (See illustration below.)

As you can see, the only moving part in a Decca cartridge is the tiny anglediron armature that holds the stylus. The mass of magnets or coils do not have to be leveraged at the other end of a cantilever; there is no haze-inducing rubber damping ring at the cantilever’s pivot point; and the motion of the stylus is translated directly to the coils and magnets that literally surround it, insuring superior rise times.

Many audio manufacturers make claims for the technological superiority of their designs. The fact that Decca “positive scanning” cartridges have been around for better than fifty years should tell you that, in this case, the claims are mostly justified. Deccas are clearer and faster than much of their competition.

Lest this turn into a love fest, let me note the not-so-good news about “positive-scanning” pickups, before I turn to the first new “Decca” in 12 years—the London Reference. First, largely because it doesn’t use a rubbery damping ring on a cantilever, the Decca cartridge is relatively “undamped.” This adds to its aliveness but can, in some instances, also add treble-range brightness and aggressiveness. As Deccas were (and continue to be) hand-made in relatively small quantities, slight variations in their construction can also cause variations in flat frequency response. (Finding a “good” Decca used to be an audiophile pastime back in the seventies, although recent-vintage Londons have been far more uniform in sound quality.)

Second, Deccas have always been very picky about tonearms. Decca’s own damped unipivot arm was once considered best. Outside of the used market, however, Decca arms are no longer available (and I would not recommend that you try to find one used, although a new model Decca tonearm will be available in the near future). Even in Decca arms, “positivescanning” cartridges were indifferent trackers. Though that has changed to an extent with the London Reference (which is equipped with a superior ultra-low-mass fine-line stylus), what has not changed is a positive-scanning cartridge’s sensitivity to dirt and groove wear. Where a moving coil will plough through dirty or severely scratched grooves (thanks, in part, to its greater mass, higher compliance, internal damping, and heavier tracking force), a Decca cartridge will not. You simply have to clean your records if you plan to replay them with a positive-scanning cartridge like the London Reference. Otherwise dust will pile up on the stylus, causing audible mistracing and, if enough dirt accumulates, outright mistracking. You will also have to live with the louder reproduction of tics and pops.

Third, because Deccas essentially use one (large) magnet to translate vertical modulations (stereo information) into electrical signals, channel separation is inherently not as high as it is with movingcoil and moving-magnet designs with separate magnets for vertical modulations. As a result soundstage width suffers a bit in comparison to the best conventional cartridges, though not enough, in my opinion, to be anything like a disqualifier.

Fourth, the Decca moving-iron cartridge is a very-high-output device. The current London models generate 5.0mV (you read that right—five millivolts), which could make them unsuitable for use with certain contemporary phonostages that may overload with signals that strong. (Be sure to keep this in mind when contemplating a purchase.)

I could go on—and on—about the practical and theoretical plusses and minuses of these fascinating beasts. But let’s look at the latest iteration.

The innards of the London Reference cartridge are essentially the same as those of the Decca Mk V that was reviewed in Issue 2 of TAS. It still uses the “positive scanning” technique, although its magnets are now made of rare-earth materials, its internal wiring is audiophile-grade, and its stylus, as noted, is an expensive ultra-low-mass fine-line diamond. (The London Reference can also be ordered with a 78rpm or mono LP stylus.) Unlike the plastic-bodied Mk V, the Reference is housed in a gorgeous two-piece aluminum chassis to provide better damping and shielding and, unlike the early Deccas, it has four output pins (rather than three). At $5295, it is also quite expensive.

I hadn’t had a positive-scanning cartridge in my system for years, so I wasn’t sure what to expect from the London Reference. I think I was imagining something like a really good Grado on steroids. Well…I was wrong.

From the moment I dropped the stylus into a groove, I knew I was hearing something I hadn’t heard before— something remarkable. I listen to a lot of twentieth-century chamber music in which strings are snapped or played with vigorous bow strokes. It only took a few bars of the Schnittke Quasi una sonata [EMI] for me to realize that the pizzicatos, collés, ricochéts, and martelés on this remarkable LP were being reproduced with breathtaking realism—not merely better than what I was used to hearing, but “breakthrough” better. As I’ve written before, most analog rigs tend to screw up the speed and duration of plucked and forcefully bowed strings (and other transients), making them sound either too abrupt or too stretched-out in tone and time. The London Reference reproduced string transients with such “fool-you” realism that I felt—and I seldom feel this way—that I’d been carried substantially closer to the absolute sound.

Happily, the London Reference’s virtues did not stop with strings. Any instrument played percussively—the mighty Bösendorfer on Grazyna Bacewicz’s Kleines Triptychon [Muza], the through-the-floor bass drum on George Crumb’s A Haunted Landscape [New World Records], the stinging cymbals on Roberto Gerhardt’s Libra [Decca Headline]—was just that much more realistic than what I’d come to expect from typical moving coils. Decca’s famous, long-standing claim of superior transient speed—which, frankly, I thought would be invalidated by the performance of contemporary mc’s— still held up.

But the London Reference cartridge wasn’t just preternaturally quick; it was also downright natural in timbre. It is weird, and rather astonishing, to hear a cartridge that doesn’t have the slight rise in the uppermidrange and treble or slight suckout in the upper bass and lower mids of most moving coils but that still maintains— and, in the case of instruments played percussively, exceeds—typical moving-coil transient speed. The results are uniquely “right”: a presentation with the lifelike air, body, and fullness of tone color of a great moving-magnet or moving-iron cartridge without the comparative sluggishness or opacity of either. While I wouldn’t say that the London Reference was quite the equal in very-low-level resolution of my thenreference Clearaudio Titanium “Fingers” moving coil—the more expensive Clearaudio Titanium is a veritable sonic vacuum cleaners when it comes to picking up fine detail and an unaparalleled soundstager—it was very, very close, with, as noted, superior realism on transients and timbres, even in the bass (which, with the Reference, is naturally round, full, fast, and deep) and treble (which was sweeter and airier than the Clearaudio, though a bit softer and less extended).

On vocals…well, the Decca has always been famous for its way with voices. But when you listen to a song you’ve heard a hundred times, like Randy Newman’s “I Love L.A.” [Warner], and suddenly realize that you can not only distinctly hear the two back-up singers—one male, one female—going “ah, Ah, AH, AH!” in the chorus, but can also, for the first time, tell from the timbre of their voices that one is Lindsey Buckingham and the other Christine McVie (as the album jacket tells you)…well, that’s pretty darn amazing!

The London Reference is far and away the best non-moving-coil cartridge I’ve ever heard and would’ve been TAS’ 2006 High-End Cartridge of the Year, if it didn’t have the bad luck of coming up against the Air Tight PC-1, which landed on my doorstep a week or two after the London Reference and, frankly, marginally outdid it in transient realism. Even at that, I would have to say that the London Reference is still the more natural in timbre and very nearly the PC-1’s equal in speed (though not in soundstage width or low-level resolution).

Now for the bad news. All of the provisos that I mentioned above about earlier Decca cartridges still apply: (1) You will need the right tonearm, preferably a damped unipivot or damped straight-line-tracker that is happy with a relatively low-compliance cartridge and a relatively low VTF of 1.8–1.9 grams (I’ve had good luck with the Kuzma Air Line, less good with the Walker air-bearing arm); (2) you will need a phonostage that is capable of handling 5.0mV signals without overloading (in my experience, the Audio Research PH7, the Lamm LP2, and the Aesthetix Io all fit the bill); (3) you will need to clean your records and the London Reference’s stylus regularly (a gentle sweep with the Decca 2+2 Record Brush should suffice for the stylus); and (4) you will have to put up with less clean tracing on well-worn discs and occasional mistracking on really deep scratches.

If you’re willing to live with these idiosyncrasies (and I grant that several can be annoying), you’ll be hard put to find a more lifelike phono cartridge. Oh, some will beat it out here and others there, but overall a properly functioning London Reference is, indeed, a reference-quality pickup—and I use it, along with the Air Tight PC-1, as my reference. Just don’t say I didn’t warn you about its quirks. TAS