Direct Drive turntables

What Lew said.

The disco days most likely help encourage the direct drive turn tables.The DJ's could back cue.You could manually rotate the platter backwards without worrying about damaging the drive system.Doing that on a belt,or idler drive could cause damage to the drive system.That was the major benefit I know of.♫

I have been an audio enthusiast for 40 years, having owned idler drive, belt drive, and direct drive turntables. I also sold audio in the golden age (mid-'70s) when the DD tables first came out, and have some frame of reference for the strengths and weaknesses of each design. Lately I have been living with an SL1210 M5G for nearly three years now, and have applied various tweaks to address this turntable's shortcomings.

My conclusion? The direct drive mechanism is just fine, and is the best part of the Technics DD 'tables, followed by precise manufacturing and excellent structural rigidity. Its weaknesses are lack of damping and a 30-year-old--that is to say, rudimental--understanding and implementation of vibration control.

This lack of vibration control creates resonances most notably in the upper midrange, that cause glare, compression, and loss of detail wrongly attributed to the DD mechanism.

These vibration shortcomings are easily addressed and inexpensive as well. To wit:
1: The platter rings like a bell. Put a better mat on it. This can be something heavy like sorbothane (I use an Oracle Groove Isolator) or with great damping properties such as the Herbies Way Excellent.
2: The tonearm also rings like a little bell. This is easily fixed for almost nothing: wrap some teflon plumbers tape around the tonearm including the joint where the headshell attaches. NOTE: This fixes that upper midrange glare, and may explain in part why people gush over the improvement of a tonearm swap. The original tonearm ain't too bad--with damping and a better headshell.
3: Get better low level resolution and inner detail with a better damping, more rigid headshell. The ones in the $40-50 range from Sumiko and LPGear (actually sourced from Jelco) make a significant difference.
4. Noise *can* come up the spindle from the drive motor, but: a) Oil the spindle; it almost certainly lost it during shipping and b) Use a record grip, clamp, or weight to dampen any motor noise (there's not much anyway) and control resonances within the LP's vinyl itself.
5: Drain and dissipate the vibration from the chassis. Put on better feet (such as SuperSpikes) and platform them to a cutting board. Isolate the cutting board with silicon gel pads, Vibrapods, or whatever soft absorbent things you want to use.

That pretty much takes care of it. Kludgy? Yeah, a bit, but they're dirt cheap and demonstrate that the direct drive was never at fault, but took the blame for the sound.

Meanwhile, the DD mechanism in a current production Technics turntable provides a level of quiet, speed accuracy, torque, and speed consistency that is not equaled in the belt drive "audiophile-approved" environment until you get into several thousand dollars.

It's a pity that the audiophile industry took this turn. I suspect some may have felt a need to discredit the Japanese direct drive mechanism because it was perceived as a threat to the (primarily) British belt-drive turntable cottage industry. I wish they'd embraced the DD motor, bought 'em by the boatload, and used their engineering to control noise and vibration. I think we'd all be listening to better turntables for less money if the industry had gone that way.

12-30-09: Elizabeth
Direct drive was a fad. Just like linear tracking arms. The 'cool' factor wore off
after a decade, and everyone went back to the belts and pivoting arms.
Another oddity was 'idler wheel' drive.

This is simply not true. The best-selling single audio component in history is the Technics SL1210 turntable with over 3 million sold over a 30-year period. That’s 100,000 units per year for three decades; I'd hardly call that a fad. Direct drives disappeared after a decade—not because they were a fad—but because the CD replaced the LP as the primary source of music. The 1st generation SL1200 came out in 1975. CD sales surpassed LP sales in 1987. That’s about a decade. Belt drive survived the CD onslaught because belt drive turntables can be made cost-effectively in small quantities; DD ‘tables need economy of scale. Belt drive turntables are the cheapest ones to make; they require the lowest start up costs provide the highest availability of stock parts such as motors and belts.

Furthermore, idler drive was far from a curious aberration; it was the industry
standard for the first 30 years of LP playback. Nearly every turntable from
that period from market-leading manufacturers Garrard, BSR, and Dual was
an idler drive turntable. It was also the drive of choice for professional
turntables from Rek-o-kut, Garrard 301/401, QRK, Russco, and Loricraft for
their reliable operation, high torque for rhythmic drive, and fast spin-up for
cueing. Even the still-highly-regarded Thorens TD-124 had a belt-to-idler
rim drive mechanism.

Belt drive didn't replace idler drive; direct drive did. I know; I was there when
it happened, managing a couple of audio stores in SoCal in 1975-6. Then in
the mid-to-late '80s most direct drive and remaining idler drive TTs died
with the takeover of the CD, leaving the belt drive cottage industry to survive
in small numbers. The Technics DDs also thrived in the dance clubs as they
were the only turntables still available that were rugged enough and spun up
fast enough for DJ work.

My biased opinion is- get a properly plinthed Lenco and you'll fall in love with your record collection all over again.