In Part 1, Copper #92, we looked at idler-wheel turntable mechanisms. In this article, we’ll look at belt-drive turntables.
The original Edison phonographs—cylinder players, not disc players—were belt-driven. Oddly, the first belt-drive turntable I’ve found didn’t come out until after WWII. Until that point, tables were either idler-wheel or one form or another of direct drive. Undoubtedly there were obscure, oddball exceptions, but I have yet to discover them.em.
The Dutch electronics giant Philips started its own record company around 1950, producing LPs. The company’s first turntable that would play LPs was the 2-speed HX301a. Like the Thorens TD-124, the drive combined an idler and belt-drive—but it did it in a completely different fashion from the Thorens. The TD-124 had a belt connecting the motor and a stepped pulley which drove the idler wheel, which then drove the platter.
On the Philips table, 78 rpm was produced by the motor driving one of two rotating drums with fixed anchor points. 33 1/3 rpm was produced by sliding the motor over to contact the idler wheel, effectively reducing the speed. Unlike later belt-drive turntables, the Philips unit only drove a segment of the platter with the belt; every other design I’ve ever seen wraps the belt completely around the platter.
The first US-made belt-drive turntable was made by Components Corporation. Billed as a “professional turntable”, it seemed to live up to its billing. As you can see from the 1954 review from High Fidelity, the Components table had a 25-pound platter, driven by a fabric belt. By the way—the author of the review, “R.A.”, was Roy Allison, who went on to be a designer for AR and later ran his own company, Allison Acoustics.
Within the next few years, a lower-priced Components table appeared, smaller, lighter, and no longer billed as “Professional”. The belt-drive Garrard RC-80 record changer appeared, and was made by the thousands if not hundreds of thousands. High Fidelity reviewer J. Gordon Holt (still a few years away from founding Stereophile) took note of the two brands in 1957:
“Belt- driven turntables are becoming increasingly popular.
By its nature the belt minimizes transmission of motor irregularities,
which can show up as hum, flutter, etc. Good
examples of belt -drive are the Garrard RC -8o changer and
the Components Corporation turntable. As for Garrard, the
secret of good performance is to keep the belts clean, replacing
when worn or frayed, and to keep a minimum of very
light oil in all working bearings (but do keep them clean).
The writer has found that changers properly set up are very easy on belts.
Flutter and rumble can be tremendously
reduced in Garrard changers by periodic lubrication of the
main turntable bearing (the center section in which the
spindle fits). From time to time it should be taken apart,
cleaned, oiled, and adjusted for end -play (just a bit – not
too loose or too tight).
“The Components turntable is inherently a fine unit. The
directions for insuring proper operation are unusually complete.
To which might be added the following: for lowest
rumble, keep the belt tension as light as possible, and
centered on the drive pulley. Make sure that the turntable
is absolutely level. If you must lift the unit, or transport it,
make sure that the table is isolated from the lower bearing –
damage here can show up as flutter.—J.G.H.”
In 1958, Fairchild came out with a playback system specifically designed for stereo. The 45-45 Westrex single-groove standard placed more stringent demands upon the rumble characteristics of turntables, and the Fairchild 412 was offered in single-speed, two-speed (33 1/3/45) and four-speed variants, the last utilizing electronic speed control to change speeds. Otherwise, drive was by two belts: one from the motor to an intermediate pulley, the second connecting the pulley to the platter. We covered the 412 in greater detail in the third part of our series on Fairchild.Fairchild ad in High Fidelity magazine, June, 1958
1960 saw the launch of the Empire Troubador, mentioned in Part 1 of our series on Empire. A belt-driven 3-speed table with a hefty Pabst hysteresis-synchronous motor and a precision-machined platter and bearing, the Empire table stayed in production with minor tweaks and variations through 1977 or so.
Acoustic Research introduced the AR-XA in 1961, and it is likely the best-known belt-drive turntable of all time, and quite possibly the best-selling, as well. Like the Components Professional, the AR featured a sprung sub-chassis designed to provide a certain level of isolation from acoustic feedback. AR founder Edgar Villchur designed the brutally-simple XA, which led the way to the Thorens TD-125, -150, and -160, as well as the Linn Sondek. Initially priced at $58, the XA was still available in the ‘70s for less than $90, and variants of the table were sold into the ‘90s. Many years, more than 50,000 units of the turntable were sold, and a cottage industry arose for mod kits and ‘tables based upon the XA, the best-known of which were made by George Merrill. George still makes some AR tweak parts today.
Into the '60s, the styling and drive mechanism of the venerable Thorens TD-124 seemed old-fashioned. The combination belt/idler drive was both complicated and expensive to build, and so the TD-150 was introduced in 1965 as a less-expensive model. Featuring square-edged styling, a suspended sub-chassis and a simple belt-drive mechanism, the TD-150 was simple to operate, maintain, and repair. Like the AR, the TD-150 and its offspring TD-160 and many variants were and are favorites for tweakers.
As Thorens moved production from Switzerland to Germany in 1968, the elderly TD-124 was discontinued. Its replacement, the TD-125, was essentially an upmarket TD-150, with bigger, beefier everything, and a fancy-schmancy electronic speed control and strobe. When I became aware of quality audio gear in the late '60s, the manual turntables featured in the US press were the AR XA, Thorens TD-125, and Empire Troubador. The AR was popular with the cost-conscious (thousands were sold to college students and professors), the TD-125 was the choice of wealthier enthusiasts, and the Empire was a perennial favorite of features in Playboy and Esquire. In the early '70s, the ultimate set-up was a TD-125 with a Rabco SL-8E linear-tracking arm, often used with a Shure V15 cartridge. Let's just say that over the years since, the TD-125 has held up better than the Rabco.
And then came Linn—eventually. A Scottish company called Ariston produced a belt-drive turntable called the RD11. Design of the RD11 was by Hamish Robertson, along with Jack and Ivor Tiefenbrun (father and son, respectively). The suspended sub-chassis/belt-drive layout was very much in the vein of the TD-150. The RD 11 was built by the Tiefenbruns’ Castle Precision Engineering, which still exists and produces aerospace-grade componentry for military and industrial applications, including the forged aluminum wheels for the Bloodhound land speed record car.
When Robertson left Ariston, Castle set up Linn Products in 1972 as a subsidiary to make turntables. The Linn Sondek—variants of which of course are still made, 47 years later—was essentially the same as the RD11. Ariston produced the RD11s, which featured a main bearing with a captive ball, rather than the single-point bearing at the heart of the RD11—and the Sondek.
Confused? It gets worse. Robertson went on to work with a company called Fergus Fons, which produced a belt-drive turntable called the Fons CQ30. Fergus Fons sued Linn over the design of the single-point main bearing. Even the original distributor of the Sondek, CJ Walker, produced their own turntable for a while.
Long story short: Linn won. All the other brands eventually went away.Hi-Fi News ad, 1973. Early Sondeks had a rocker switch, grooved base, and prop for the dust-cover. Later--and current---models have a push-switch, plain base, and friction hinges.
After that point, belt-drive and direct-drive tables followed a parallel path, until turntables began to vanish from the Earth. Direct-drives have to have very high quality motors in order to last and perform reasonably well. Belt-drives can range from precision instruments like the Linn and beyond, down to bargain basement tables. Most tables from the '80s and '90s which aspired to audiophile cred were belt-drives, like the Harmon Kardon models from the '80s, shown below.
Following the vinyl revival of the last decade, anything goes. There are far too many belt-drive turntables being made today to even attempt a list of them. Look for yourself, and see.
In our next installment, we’ll look at direct drive tables. —and no, they didn’t start with the Technics SP-10. The story is a lot longer and more involved than that.