Listening #49

Here's something that's difficult to visualize but nonetheless true: If you attempt to isolate from their environment the working bits of a record player—the main bearing, platter, tonearm, and cartridge—by means of an elastic drive belt and a suspended subchassis of the usual sort, you'll create almost as many problems as you solve.

If your suspension system is designed correctly, then the fragile relationship between cartridge stylus and record groove will be less vulnerable to certain kinds of interference; additionally, the soft drive belt may indeed filter out some of the noise generated by the motor. But any system that's free to rotate in relation to the rest of the world, and to an energy source such as an electric motor, will do just that: Torsional modes will be set up, and the subchassis will attempt to rotate about its own center. If the center of the suspension happens to coincide with the platter bearing—as is the case with most such record players—you'll be left with a slight, continual twisting movement between the platter on one hand and the tonearm and cartridge on the other, resulting in a slight, continual modulation of the signal. And that ain't good.

I never gave any of that a thought until 1985, when an engineering-school graduate named Touraj Moghaddam introduced the first Roksan Xerxes turntable to the audio world. Moghaddam understood the problem and addressed it in two distinct ways. First, because he regarded groove drag as among the causes of the torsional modes described above, Moghaddam gave the motor casing its own bearing and restricted its long-range movement with a sprung tether, so that the revolving armature could still drive the system. Brief, momentary increases in drag were thus absorbed by the motor itself, and changes in platter acceleration were mitigated. Second, Moghaddam devised a turntable suspension that was less free to move in the lateral plane than most, thus restricting the rotation of the suspended parts relative to the motor.

An interesting side note: Some Linn aficionados think that the stringent requirements for adjusting and clamping the LP12's tonearm cable might accomplish the same thing. A properly dressed cable allows the suspension to bounce nicely up and down, but restricts its ability to rotate in one direction or the other. Makes sense.

As it turns out, Roksan wasn't the only company to notice the problem—or offer a solution. In the 1980s, Pink Triangle designer Arthur Khoubesserian created a lightly sprung turntable in which the center of the suspension and the platter bearing were separated by a considerable distance—mitigating the relative movement between tonearm and platter, and preventing the phase modulation of the signal, as he described it.

Then, in the mid-1990s, for Pink Triangle's Anniversary turntable, Khoubesserian went a step further: He put the motor right on the subchassis, leaving, as the only links between his turntable's working parts and the rest of the universe, the three suspension springs and an intentionally delicate signal connection. Which was almost the same as having no links at all.

The motor in the Pink Triangle Anniversary was a relatively small, lightweight DC type, said to be freer from unwanted vibrations than most. Still, no motor is perfectly silent, so Khoubesserian used three soft rubber bushings to decouple it from the Anniversary's honeycombed subchassis. Further, in keeping with the Pink Triangle design theory that I described in last month's column, Khoubesserian placed the motor between and in line with the main bearing and the tonearm pivot—at the 2 o'clock position, viewed from above. (For you latecomers: Having the motor in either the left-front or right-rear position puts the drive belt more or less in line with rather than perpendicular to the cantilever of the phono cartridge, so that the motor will contribute the least possible amount of vibration to the signal output.)

Whether for those or some other reasons, Pink Triangle's Anniversary remains among the four or five turntables that have most impressed me over the years, and I was sorry when the company went out of business. But now that Arthur Khoubesserian has returned to the hi-fi world with a new company, The Funk Firm, one might wonder how many of the Anniversary's design distinctions have survived from that life to this. The answer: almost all of them.

Wow is a noun
At least in a functional sense, the new Funk Firm Vector turntable ($1449 without tonearm) and its less expensive brother, the Funk ($859 without arm), both resemble a Pink Triangle Anniversary subchassis—albeit one that has been distended in one direction and perched on three feet rather than hung from a frame-type plinth. Both players are distinctively spare, low-mass designs, and both use DC motors, compliantly mounted in line with the platter bearing and tonearm pivot.

In addition to those products, Arthur Khoubesserian designs and manufactures modification kits for certain Pink Triangle turntable models, and for the Linn Sondek LP12—the latter being the focus of my attention. The Funk Firm offers two levels of LP12 modification kits: Stage 1, called Funk Link ($1599), combines the carbon-fiber top plate I described last month, plus an ironless-rotor DC motor and an outboard power supply for same; Stage 2, the Vector Link ($1859), adds an upgraded DC motor, an upgraded power-supply PCB, and an entirely new subchassis, plus various interesting bits and pieces to facilitate installation. The Vector Link also includes a light, semirigid platter mat, the Achromat, which is available as a separate accessory for $100.

If you buy both kits at once, you get a nice break of $299 on the price (for $3159 total), and two of the elements described above are combined into one: The motor comes premounted to the subchassis, with a specially made wooden motor plate and three metal-and-rubber "bumpers" of the sort used to fasten together different segments of an Alfa-Romeo driveshaft, albeit on a different scale (footnote 1). And that's how my review samples of the motor and subchassis were supplied: together.

Moreover, the subchassis came fitted with Stage 2's Vector Drive: a mechanical system comprising two 1"-long axles bolted to the subchassis from beneath, and two molded pulleys designed to ride those axles once they've poked their way up through the openings made for them in the Funk Firm top plate. Used with the kit's own belt, those idler pulleys combine with the motor pulley to form a three-point drive intended to prevent wobbling in the platter bearing—and thus the noise and unwanted movement that may well result.

My original plan was to try the different Funk Firm modifications in an incremental fashion. But in light of all the above, after installing the carbon-fiber top, I couldn't see a practical alternative to skipping directly to The Big Finish.

Footnote 1: I could be unkind and describe the distinction as favoring the Funk Firm, for the greater apparent durability of their "bumpers." But I won't.
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