Analog Corner #294: TechDAS Air Force One Premium turntable & Graham Engineering Elite tonearm
In 2013, when I first wrote about it (footnote 1), the TechDAS Air Force One ($105,000) was that company’s best and most expensive turntable; it joined the handful of products that have earned an A+ in our semiannual Recommended Components feature—a rating that remained in place for six years. But too much time has passed since the Air Force One was auditioned by a Stereophile writer, so it has now fallen from that list.
The Air Force One is still available, but it’s now a special-order product that, according to distributor Graham Engineering, can take up to six months to deliver. So rather than revisit the One, I decided to check out the readily available Air Force One Premium—the upgraded and costlier version ($145,000). The TechDAS Air Force Two and Air Force III also now have Premium versions, but hey: one ‘table at a time!
Meanwhile, the $19,500 Air Force V, which I reviewed in the September 2019 issue, ended up in Class B (where I said it should go), just above a $1500 VPI! Oops. My thinking at vote time was: Had I put the Air Force V in Class A along with the far more costly TechDAS turntables, that would cheapen the Air Force One’s own Class A rating. In retrospect, I don’t think I’ve heard a ca-$1500 turntable that belongs in Class B.
What distinguishes a $145,000 Air Force One Premium ($162,000 with Titanium upper platter, as supplied) from a “plain old” $105,000 Air Force One? The upgraded ‘table’s chassis is identical to the original’s. The two biggest differences are a new and far more complex, more effective, and more convenient air delivery system that “floats” and thus isolates the chassis, and all-new motor-drive electronics.
The Premium retains the original turntable’s air bladder–based suspension system, but it’s been improved with an automatic, continuous pressure-monitoring system. And in light of my experience with the original Air Force One, the new air delivery system isolates more effectively. In addition, bladder inflation no longer relies on a bicycle pump. Instead, the new system incorporates a motorized air pump: A coiled hose, connected via a pneumatic fitting, is used to inflate the bladders, then keeps them properly inflated as needed—which, during the months I had the Air Force One Premium, was never. The system was 100% stable and required no topping up.
As on the original Air Force One, removing a small magnetic plate on the chassis front reveals three air plugs, one for each bladder. On the front panel of the ‘table’s new outboard Air Condenser/Air Charger unit is a diagram of the turntable chassis in which the position of each bladder contains a button switch and an LED indicator; the latter glows red when that bladder is underinflated and green when it is properly inflated, at which time the air pump automatically stops. The new unit also doubles the air capacity of the original’s, reportedly for smoother air flow and more dynamic sonic performance.
Each of the three insulators also incorporates a rotary height adjustment mechanism that allows for precise chassis leveling once the bladders have been inflated.
I’ll skip the rest of the inflation and suspension setup details, other than to say that when you pay $100,000 or more for a turntable that includes an inflatable air-suspension system, an elegant and effective automatic inflation system—not a bicycle pump—should be included. And now it is. This system takes the guesswork out of the inflation process.
The newly refined isolation system proved extremely effective. I could bang on the platform the turntable sat on—a six-foot HRS base made for large, heavy turntables—and I heard nothing through the speakers, not even the faintest tap. This is as effective a turntable isolation system as I’ve used.
What’s more, I could tap the turntable’s main chassis while a record played; nothing got transmitted through the system that way, either. That’s obviously not due to the suspension but rather to the combination of a high-mass, three-material sandwiched chassis (only aluminum is specified, so I don’t know what the other two materials are) and the air-suspension platter bearing. I could even put the stylus onto a stationary record, after applying the vacuum hold-down, and tap on the record directly adjacent to the stylus—and again hear nothing through the speakers, even with the volume cranked up.
In addition to the aforementioned Air Condenser/Air Charger unit, the Air Force One Premium comes with a second outboard unit—the two can be stacked—containing a pair of totally silent air pumps. One floats the platter; the other is for the platter’s vacuum hold-down system.
The compressed-air systems of the two outboard chassis are connected to the ‘table via a total of six hoses—one each for platter float and vacuum hold-down and four to deliver, stabilize, and monitor the suspension system and smooth the airflow that floats the platter. It is a complex, sophisticated system designed to ensure instant, secure platter levitation and vacuum hold-down (as well as instant vacuum release), smooth, silent operation, and complete freedom from air “pulsing.”
It’s a long way up to this system from the Eminent Technology 2 air-bearing tonearm I once owned, which was pressurized by an aquarium pump whose pulsing was “smoothed” by a “floss”-filled 5-gallon plastic water bottle!
A DC amplifier controls and monitors the rotational speed of the outboard AC motor, which is housed in a substantial outboard pod. The motor, topped with a crowned, machined–stainless-steel pulley, drives the platter via a flat, nonflexing, surface-polished polyurethane-fiber belt. The main platter of nonmagnetic, forged stainless steel weighs approximately 42lb. You have an upper plate choice of aluminum (approximately 9lb) or pure titanium (13lb) for respective totals of 51 and 55lb.
Based on the clearly audible differences between the two platters I auditioned for the original Air Force One review, I’d say that if you’re already planning to spend $145,000 on a turntable, why not go the $17,000 extra for the titanium upper platter? It’s well worth spending the additional money to get the extra levels of background quiet, dynamic punch, and bass solidity the titanium upper platter produces. The total weight of the main chassis, platter, and outboard motor is in excess of 160lb.
The fit ‘n’ finish of the original Air Force One was what you’d demand and expect from such a costly product, and though I don’t have an original handy with which to compare the Premium, it appears that TechDAS has further upped the finish quality.
Get your motor running
TechDAS claims its unique, non-stretch-fabric belt, used in conjunction with the frictionless air bearing platter, produces direct drive–like speed consistency. Achieving this result requires careful setup that, considering the ‘table’s cost, will surely be done by a well-trained dealer.
Because the belt offers no flex, the motor pod must first be angled so the belt can fit over the pulley, at which point the fit will be loose. Critical belt tensioning first requires precise motor pod positioning using supplied spacers. Loosening fixing screws allows the motor to slide, within the pod, farther away from the platter as needed.
A calibration mode then guides you to the proper tension, which is within a narrow range of pulley-to-platter distances that, using the Feickert Platterspeed app, I found produces results that are measurably and audibly different, the latter subtly so.
Due to the air bearing’s low friction and the belt’s nonelasticity, the motor’s job is to provide a small, encouraging “nudge” to the platter’s rotation while at the same time preventing a “runaway” platter—certainly more so than it is to maintain a tight, controlling grip. The new motor control system monitors and adjusts as necessary the platter rotation speed to keep things rolling smoothly.
Footnote 1: See my review in the April 2013 Stereophile, and my reassessment in the April 2016 issue, neither yet reprinted on this website.
Footnote 2: TechDAS, Stella Inc. 51-10 Nakamarucho, Itabashi-ku Tokyo 173-0026, Japan. Web: techdas.jp. US distributor: Graham Engineering, 25M Olympia Avenue, Woburn, MA 01801. Tel: (781)932-8777. Web: graham-engineering.com.
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