Analog Corner #281: Klaudio KD-ARM-AG12 tonearm and Ikeda & Tedeska phono cartridges
How do you like your tangential-tracking tonearm: with a captured air bearing? If so, a stationary bearing and moving rail—or a moving bearing and stationary rail? A hovercraft-style air bearing? Trolley-wheel or servo-mechanical bearing? Or pivoted, with some kind of offset at the pivot or the headshell—or both? In today’s crowded market of analog playback, you can buy whatever type of tangential tracker you prefer, from Bergmann, Clearaudio, Kuzma, Reed, Schröder, Thales, and others.
Or maybe you’re okay with a plain ol’ pivoted tonearm that describes an arc across the record’s playing surface. The possibilities here, too, are seemingly limitless. It’s a great time to go analog.
I think I’ve covered these concerns in almost every review of a tangential tracker I’ve written in the past 30 years, and I’ve owned some of those arms. I eventually returned to plain ol’ pivoted arms, but don’t let that discourage you from going straight. It certainly hasn’t discouraged any of the designers at the companies named above—or Klaudio’s Peter Cheon, who for years has been working on this complex pivoted tangential tracker. Cheon, best known for Klaudio’s cavitation-based record-cleaning machines, has sent me more than one of these arms that turned out not to be ready for prime time, but all of them were close. His current tangential-tracking arms, the KD-ARM-MP and -AG models, look, feel, set up, and perform like finished products—hence this review (footnote 1).
Klaudio sent me their top model, the KD-ARM-AG12, a 12″ arm with end-of-album auto-lift and remote-control electronic cueing. It and the 10.5″ version cost the same: $11,999.99. The standard MP models, without auto-lift or electronic cueing but otherwise identical, sell in either length for $8999.99. The $3000 difference is a lot to pay for those conveniences, but they’re very cool features that some will find worth it. Both versions come elegantly packed in a handsome, suitcase-like box.
The KD-ARM-AG12 looks like a super-complex assemblage of hinged and sliding parts, and it is. I’m experienced at setting up tonearms, but this one’s multiple setscrews and moving and sliding parts intimidated me—until I thoroughly understood those parts and their functions.
The KD-ARM-AG12 combines a number of familiar elements. The columnar knob for adjusting the cartridge’s vertical tracking angle (VTA) is reminiscent of Graham Engineering’s; the two rectangular carbon-fiber, articulated arm structures, and the independently moving counterweights, are reminiscent of Thales’s arm; and the Klaudio arm’s front termination is an old-school collet that’s ready for your Ortofon SPU, Technics, or other similarly designed standard headshell.
Vertical movement is via a standard gimbaled bearing: simple enough. The difficult part—maintaining the cartridge’s tangency to the groove with a pivoted arm—is accomplished with two different design elements. One is the articulation of the twin carbon-fiber tonearm “beams,” accomplished with joints located just behind the headshell collet, allowing the headshell to slowly pivot as the arm swings through its arc. This is similar but not identical to the approach used in the Thales tonearms and even the arms fitted to the old Garrard Zero 100 turntable.
Working in tandem with the arm’s articulation is a mechanism whereby the entire tonearm, bearings and all, slides nearer to or farther from the record spindle, also depending on the arm’s position as the stylus traces the record groove. This mechanism is mostly hidden from view, although a cam of sorts seems to be involved.
Stylus alignment—what we’d normally call overhang, except in tangential tracking there’s no over—is set using a two-section Tonearm Alignment Tool supplied with the KD-ARM-AG12: One end of this fits over the record spindle, while the other is locked in place over a portion of the aforementioned sliding mechanism. Then comes the cool part: Also supplied with the Klaudio arm is a Laser Tangent Tool: a compact, adjustable laser projector that’s positioned next to your turntable, close to the platter, and that lays down a green radial line aimed at the center of the spindle. With the Tonearm Alignment Tool still in place, you loosen a set-screw and adjust the arm bearing’s sliding mechanism until the laser shines on the stylus itself—then lock the set-screw and you’re done. Minimal azimuth adjustment is also possible—a separate tool for this is also included—but it was never clear to me if antiskating compensation is applied.
The KD-ARM-AG12’s remote cueing feature lets you raise or lower the arm using a large, illuminated button located on the Laser Tangent Tool. The motorized mechanism raises and lowers the cueing bar and automatically lifts the arm at record’s end. It’s easy to set where that occurs, and adjust as needed.
Knowing I was about to review the VPI Avenger Reference turntable (see December 2018), Peter Cheon brought an aluminum armboard drilled with the single hole into which the threaded arm pillar goes, locked in place with an enormous plated nut. Klaudio also makes a massive, standalone arm platform ($300).
One of Cheon’s most interesting innovations is how his headshell terminates in the collet. Instead of the usual interior pins, to which you connect headshell wires that attach at the other end to the cartridge pins (which, in the case of long cartridges, often leave insufficient room), he’s devised a termination to which the wires are soldered, thus saving room and eliminating that break in the electrical signal. The circular terminal block fits through the rear of the headshell termination, and its protruding rear contacts connect with the collet’s. Why did it take so long for someone to figure this out?
Performance and Sound: I tried numerous cartridges in the Klaudio KD-ARM-AG12, including EAT’s Jo No.5 moving-coil ($1295), Sumiko’s Moonstone moving-magnet ($299), Ortofon’s A95 ($6500), and a few costly Lyras.
Despite the complexity of the Klaudio KD-ARM-AG12, once I’d set it up, installing and adjusting cartridges was relatively easy—that green laser actually made it fun. And since the two supplied headshells are slotted, stylus alignment could be independently set for each cartridge, which made them easy to swap out.
The cueing bar was less than firmly affixed to the lift mechanism (I was told this was “normal”), which made for somewhat wobbly lifting and lowering: cueing was not precise. Other than that, using the KD-ARM-AG12 was mostly similar to using more conventional tonearms. One other difference is the cable running from the base of the arm-lock mechanism—a very sturdy and reliable design that actually locks the arm—to the Laser Tangent Tool and its cueing pushbutton. I had to be careful not to get tangled in it.
Otherwise, the KD-ARM-AG12 allowed the various cartridges to behave well in the grooves and track effectively, which, after all, is its tangential mission. For instance, using the Ortofon Test Record: Accuracy in Sound, the EAT cartridge met its peak trackability specification of 80µm, above which it distorted. That performance should suffice for every LP in your collection other than cannon-fire passages in Telarc’s original 1979 recording of Tchaikovsky’s 1812 Overture.
Aside from its less than fully expressed bottom-end extension, the arm’s overall spectral balance was generally neutral, allowing the cartridge’s tonal personality to express itself, though compared to either of VPI’s Fat Boy arms mounted on the same VPI Avenger turntable that I reviewed in December, the Klaudio arm was somewhat thin in the midband, and images weren’t quite as solid and three-dimensional—the Fat Boys were more fully fleshed out. Relatively, the Klaudio arm provided a greater sensation of “air.”
The KD-ARM-AG12’s biggest shortcoming was its lack of bass punch, and of dynamic slam in general. This isn’t surprising, given the design. Cheon, in my opinion, so focused his design on one design goal—tangential tracking—that he was willing to give up structural and mechanical rigidity and a clear energy path from the record-stylus interface, through the arm, and to a solid mechanical ground.
Rega Research has correctly characterized the turntable as a “vibration-measuring machine.” With so many moving, sliding, and dangling parts, the Klaudio arm must, on a microlevel, be just as much a vibration-producing machine. Makers of unipivot arms tout that design’s single energy ground path, while makers of gimbaled-bearing arms claim that whatever slight reduction in mechanical grounding four points produce in comparison is more than offset by far superior mechanical stability. And so it goes. The Klaudio arm’s mechanical complexity produces both a convoluted mechanical ground path and, in multiple places, sacrifices mechanical rigidity to the goal of tangential tracking.
Ideally, a playback stylus would track a record groove tangentially, because that’s how the groove was cut in the first place, but in my experience, the amount of linear tracking error (LTE) produced by a properly designed and set up 9″ pivoted tonearm is negligible and inaudible, producing less distortion than what’s produced by the rest of a typical audio system.
Footnote 1: Klaudio, 2840 West Valley Highway N., Suite 101, Auburn, WA 98001. Tel: (253) 249-7813. Web: klaudio.com
Published at Tue, 08 Jun 2021 18:58:45 +0000