TechDAS Air Force Zero turntable

The Air Force Zero turntable is very large for a turntable, but it is not as large as a house. At $450,000 for the base model, it does, however, cost as much as many houses and more than many others (footnote 1).

This observation will set off howling among some audio enthusiasts of a sort that never happens in the wine world, for instance, where well-heeled oenophiles routinely spend large sums for a short-lived thrill.

Yes, I know, some people are homeless. Others are hungry. Isn’t it wrong to spend the equivalent of a suburban home on a means of playing records? It’s a legitimate question, and I don’t dismiss it, but it’s not for me to say, except when it comes to my own choices. It’s a decision each of us must make for ourselves. Now, where was I?

Nishikawa’s ultimate analog statement
I’m sure TechDAS founder Hideaki Nishikawa has heard more turntables than I have, and I’ve heard a lot of them.

He received his mechanical engineering degree in 1963, when I was still in high school. He then joined Stax Ltd., where he was instrumental in developing that company’s legendary electrostatic headphones. He was involved in other projects, too.

Nishikawa-san left Stax in 1980 to join Micro Seiki. As manager of the technical department, he was involved in the development of a long line of turntables including the company’s statement product, the SX-8000, which remained in production from 1981 until 1990. Find an online photo (footnote 2) and you’ll notice more than a passing resemblance to the Air Force turntable line, especially in the large metal platter topped with a double-lipped vacuum hold-down system. Also notice how the outboard motor drives the platter with a belt around its periphery.

Micro Seiki’s slew of talented engineers produced turntables and tonearms for other brands and performed precision machining work for other industries, much as SME does in the UK and Ortofon does in Denmark. Diversification helps with a company’s stability—hence its longevity—something every audiophile should consider when investing in high-dollar gear. What good is a lifetime guarantee from an out-of-business company?

In 1989, Nishikawa founded Stellavox (now Stella, Inc.), an importer (into Japan) of high-performance audio gear. In 2010, he started TechDAS as the Stella house brand.

Even if you’re not a fan of TechDAS turntables, you have to admire Nishikawa’s passion and decades of accomplishments and the consistency of his vision of what constitutes good turntable design.

Nearly a decade has passed since TechDAS introduced its first turntable, the Air Force One. Last year, I reviewed the updated version of that ‘table, the Air Force One Premium, which is now second to the top of the TechDAS line. Six months ago, the formidable Air Force Zero arrived in many crates. Assembling it took a team of two several days, but since then, I’ve been listening to it and enjoying everything about it, from its impressive size, which at first felt almost cartoonish (a feeling that quickly dissipated when the stylus touched the record with a gentle “bip”) to its ease of use and trouble-free, non-fiddly performance.

We’ll probably see a few product enhancements throughout the TechDAS line. Maybe we can hope for a truly affordable model that retains the line’s key features, priced below the current “entry-level” V, or perhaps a more compact, less expensive version of the Zero: call it Zero.1. But to me the Air Force Zero looks very much like the ultimate fulfillment of Hideaki Nishikawa’s turntable vision.

The massive Zero took three years to develop, from inception to launch. Just watching the technicians unpack the Zero made clear the company’s careful attention to detail. All of the many modules, feet, and platters, and the ultraheavy main subchassis assembly, were securely and efficiently positioned in stacks of subpackages within each crate. It took two people almost two full days to repack it for secure shipping, and of course it took much longer to set it up.

How many of these half-million-dollar, 725.5lb boats does TechDAS intend to float? I was told that TechDAS is at least halfway through a 40-unit run. The serial number of the review sample was 018.

The TechDAS Air Force Zero’s platter-speed statistics measured two ways: with the PlatterSpeed app and the Shaknspin. The low-pass filtered speed deviation is 0.02%.

The three-phase, synchronous Papst motors used in the AF Zero are new old stock, originally used to spin Revox tape recorder capstans. (The size of the AF Zero’s production run was determined partly by how many new-old-stock Papst, high-torque, three-phase, 12-pole AC, synchronous motors the company was able to source.) TechDAS takes them completely apart and rebuilds them into highly modified motors that include a customized air-bearing spindle and flywheel. The rotor assembly floats, so no load is applied to its thrust plate, minimizing noise and producing the largest possible moment of inertia, which TechDAS has precisely calculated. The flywheel and rotor together weigh 5lb and produce a moment of inertia of 116lb˘cm².

TechDAS’s goal for the motor was to produce “virtually zero wobble” thanks to the combination of air and metal bearings, the “enormous” inertia generated by the flywheel effect, the extremely high S/N ratio made possible by the air bearing, and what TechDAS claims is the best speed stability and consistency of any Air Force turntable—the latter due to a new electronic drive circuit designed for stable, precise rotation with low vibration.

The new, multistep drive system begins with a sensor that communicates platter speed to the micro-processor. The desired rotation frequency is synthesized by a “Direct Digital Synthesizer” (DDS) with reference to a crystal oscillator. Each motor phase is driven by its own 50W power amplifier. A three-phase generator circuit creates the phase shift in place of the more typical capacitors, which are more error-prone and deteriorate with age. A torque-switching circuit adjusts motor voltage during startup or when changing speeds to quickly achieve rated speed, at which point the speed locks and torque is decreased to further reduce vibration.

A strong motor is needed during startup because there’s a lot of mass to move: The Air Force Zero doesn’t have a platter; it has a stack o’ platters. On the bottom of the stack is a 15¾”, 80lb platter made of nonmagnetic forged stainless steel; above that is a 43.5lb, 12.2″ platter made from the same material; the drive belt, which is made of “polished and non flexible polyurethane fiber” and isn’t stretchy, wraps around this platter. Above that is a 40lb, 12.2″ platter made of cast gunmetal, a form of bronze. The platter second from the top is also stainless steel. It weighs 48.5lb.

The top platter comes in two versions. The standard version is titanium with a “special surface hardening treatment.” It weighs 13lb. For an extra $50,000, you can get a tungsten top platter that weighs 50lb. Both are topped with a soft mat and vacuum-holddown lips. The upgraded platter was supplied with the review sample.

The total weight of the platter assembly comes to 229.3lb with the standard titanium top platter and 266.7lb with the upgraded tungsten top platter. Altogether, the main chassis, including the motor unit and with the heavier top platter, weighs 765lb.

The five stacked platters are “held as one,” not by mechanical couplings but by air pressure, a system similar to the vacuum LP hold down. When properly set up, all the platters are, of course, level, including the top surface. When the air pumps are activated, this 266.7lb mass (with the upgraded top platter) floats and rotates on a 10µm layer of compressed air! Plus, the entire assembly is air-suspended on the four corner pods.

The power supplies and the various pumps occupy three additional chassis weighing 84lb. The machined stainless steel base frame weighs 220lb.

All of which raises an obvious question: What kind of rack do you place such a heavy turntable on, especially one with an asymmetrical footprint? The VXR stand made specifically for the Zero by HRS adds $52,000 to the price.

Rereading what I just wrote makes me think of Rega Research’s Roy Gandy, whose approach to turntable design is precisely the opposite of Nishikawa-san’s.

Gandy’s ultimate goal would be a no-mass design; for his ultimate ‘table, the limited edition Naiad (about $41,000 with arm), he settled for a superlow-mass, ultrastiff carbon-fiber composite chassis. Wouldn’t a head-to-head comparison be interesting?

Logistics
Fitting this enormous turntable into my room required that it be placed on the opposite side of my room from where my equipment rack sits. Phono preamps were placed close to the turntable. I used two 5.5m runs of balanced Tara Labs Zero Gold interconnect cable to get the phono preamp output across the room to the line preamp.

I borrowed a 6m length of AudioQuest Hurricane AC cable and plugged it into the PS Audio PowerPlant 15, since I’m still waiting for the final permit for the transfer switch bypass. Because so many boxes needed power, I used an RSX Technologies Power8 multioutlet, fully shielded extension box fitted with eight solid copper AC receptacles and no sound-damaging surge protectors.

Footnote 1: According to Zillow, the average US home price is $287,148, a 13% increase in just one year.—Jim Austin

Footnote 2: As I write this, there’s one on eBay, offered at $40,000. Some audio products hold their value.

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TechDAS, Stella Inc.

51-10 Nakamarucho, Itabashi-ku

Tokyo 173-0026, Japan

techdas.jp

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Associated Equipment

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