'70s Direct Drive Turntables (and Tonearms)

This is a follow up on the road less travelled article. In 2017, I went on a quest for direct drive turntables that I could acquire for under $250. For the past year I've been tinkering and listening to these four 70s era direct drive turntables to find out whether a direct drive turntable has a place in my ever-growing collection of audio equipment.

Each unit has its own unique approach to direct drive turntable design and was available either as an integrated unit (with tonearm) or as a plain motor unit. The Denon DP1250,  Kenwood KD500 and JVC QL5 are mid-priced models from the late 70s, while the Sony TTS2500 was a first generation early 70s top of the line direct drive unit designed to compete with the original Technics SP10, which, unfortunately, was not within my budget. 😞

Turntables

JVC QL5

JVC introduced the world's first quartz locked turntable in 1974. The QL5 employs quartz locked circuitry to control its 12 pole 24 slot DC type motor. Its jet black plinth is made out of heavy particle board. The motor unit was also sold sans tonearm as the QL50.

Kenwood KD500

Instead of the complex electronics found in the Denon, JVC and Sony, the KD500 uses a relatively simple servo circuit referenced to a frequency generator modulating an 8 pole 24 slot brushless DC motor. This turntable developed a following in the late 70s due to the use of a highly inert and heavy synthetic marble plinth.

 This particular unit was loaned to me by my buddy Ding. He's had it stored for many years. It ran way too fast at first turn on so I replaced these four bulging capacitors immediately.

Denon DP1250

Unlike the two preceding turntables, the DP1250 uses an AC motor which minimizes cogging, according to period Denon sales literature. The motor is governed by a unique tape head inspired speed regulating system. The plinth is a substantial plywood/particle board laminate similar in mass to the JVC.

Sony TTS2500

The Sony TTS2500 is the motor unit of the worldwide bound Sony PS-2250/2251. Just like the Denon, it also uses an AC motor regulated by a servo circuit that is claimed to be practically cog-less in operation. This JDM (Japanese Domestic Market) model requires a 100V step down transformer. The half-finished laminated plywood plinth was DIY'ed by yours truly.😎

Tonearms

In a typical audiophile shootout these turntables would have been fitted with the same tonearm/cartridge combination and plinth. But this was not practical since I wanted to test under real world conditions. So to satisfy JE Labs' retro-centric streak,😉 for the Denon and Sony, I chose period correct gimbal bearing type tonearms that are known to perform on a similar musical level as those supplied with the QL5 and KD550.

JVC QL5 Tonearm

The QL5 is equipped with a tonearm that looks like an economy version of their well regarded UA-5045. With an effective length of 245mm, it is a bit longer than the three 237mm tonearms below.

Kenwood KD550 Tonearm

Ding had a Grace 707 installed before moth-balling this KD500. For some reason that tonearm went AWOL. Fortunately I had the original tonearm supplied with the KD550 in my stash. There are claims that this may have been OEM'd either by Acos or Micro-Seiki?

Rega R200

It would've been nice if I had something along the lines of a Denon DA305 to fit on the DP1250. However, the Acos OEM'd Rega R200 I installed is also a well respected 70s classic. 

Grace 540L

I've always had a soft spot for Grace/Shinagawa tonearms ever since the Grace 707 opened my ears that fine quality tonearm design produces nice sounds. This Grace G540L has similar mass to the other three above. The lack of a cuing device and anti-skate betrays its pro-application heritage. It is the oldest of the bunch making it the perfect partner for the TTS2500.

Cartridge

Denon DL103R

 For critical listening I relied on a Denon DL103R mounted on a Sumiko HS-12 head-shell. But this didn't prevent me from mounting a variety of cartridges in my stash ranging from the cheap 'n cheerful AT 3600L to an Ortofon SPU.

Time travel to the 70s

 Without hesitation, I would choose any of these turntables over the 3-point suspension belt drive turntable I used and tweaked to the max in the 80s. The direct drive system has the sure-footed speed stability which eventually lured me to the TD124 in the late 80s. I should've jumped at bargain priced top of the line direct drives to play with in the 90s...alas, hindsight is 20/20.

Since direct drive solved the ills of wow and flutter, and noise which plagued the belt and idler drive system respectively, there should be minimal difference in the way any direct drive motor unit should sound, right? Not quite...

Denon AC motor (top)
Kenwood DC motor (bottom)

My most surprising discovery after living with all these turntables this past year was the difference in sound between the motors that power them. The DC-motor-powered JVC and Kenwood consistently sounded analytical, cold and forward, akin to a digital source, while the AC-propelled Denon and Sony were characteristically more laid back and warm, just like what I associate with analog sound.

 However, to put things in perspective, the Sony still outperformed the other three direct drives in key musical aspects. In particular, there is a "hardness" and loss of composure in complex musical passages that prevailed on the three units with the Sony exhibiting only the very least amount.

Sony TTS2500 + Stax UA-3NL

Still, the TTS2500 could not eclipse the performance of the 301 or the TD124s. But it is the only direct drive in this group to come close in mimicking the stately authority of the esteemed idler driven classics. 

For this achievement, I crowned the Sony with a 12" Stax UA-3NL tonearm.🍻

Grace G707 + Denon DP1250 = road less travelled

The 70s through the early 80s was the era of great development in direct drive turntable technology. It was only stifled by the introduction of the CD player in 1982 and to a minor degree by the revived interest in the classic suspended sub-chassis belt-drive system within the audiophile community.

Luxman PD444
[image from Pinterest]

Although I was exposed to some of the great direct drive turntables from the 70s, like the Luxman PD444 and the Technics SP10 MkII in a Mitch Cotter base in the home system of my late DIY audio mentor Tom Cadawas, I never had a direct drive turntable in my audio system till now.

Technics SP10 + Mitch Cotter base + FR66s
[image from dallas.freeclassifieds.com]

This was probably due to the almost cult-like indoctrination inculcated by early 1980s Haymarket publications like Popular Hi-Fi and Hi-Fi Answers exalting the virtues of the 3-point suspended belt-drive from the land of kilts vs. the evils of cogging and servo hunting direct drive turntables from the land of the rising sun.

Goldmund Studio
[image from Pinterest]

Even though the late Harry Pearson of TAS used a direct drive Goldmund Studio in his reference system, just about every reviewer for TAS and Stereophile had either a Linn, SOTA or VPI belt-drive turntable. These were merely an 80s techno-rehashing of Edgar Villchur's AR turntable design from the early 60s, which effectively killed the idler drive system except for professional and broadcast applications.

Kenwood KD500 + Grace G707
[image from kintavalleyaudio.blogspot.com]

Despite camping happily with my idler-driven turntables since the 90s, the specter of synthetic marble-based Kenwood KD500s and Denon motor units in heavy laminated plywood plinths sitting on the shelves of Audio and Stereo Exchange as well as the trade-in section of Harvey and Leonard Radio stores in early 80s NYC, haunted my dreams. 😱

Pioneer PLC590
[image from vinylengine.com]

Since my Thorens TD124s are currently in storage and the Garrard 301 plinth does not have provision for mounting a shorter tonearm like the Grace G707, acquiring a direct drive motor unit became a good excuse. 😉

Denon DP1250

The first direct drive I spotted was a reasonably priced Denon DP1250 motor unit on an original plywood plinth from the late 70s. While waiting for the package to arrive, I did research on direct drive turntables + DIY refurbishing tips.

Details on how the painted magnetic stripe (above)
is monitored by the tape head (below right)
to regulate speed 

Luckily, the DP1250 just needed a tiny bit of cleaning + a mist of Deoxit on the pitch control rheostat. The motor was extremely quiet. I couldn't detect any rumbling noises through the plinth using a stethoscope.

 I left the motor unit on while cutting a new arm board out of 3/4" plywood to mount the Grace G707. When I returned to install the tonearm, the strobe had not drifted the tiniest bit.

Grace G707 on a stable platform

Denon DP1250 + Grace G707 - reminiscent of 
turntable/tonearm combos I used to see in the trade-in section 
of audio stores in NYC in the early 80s

Whether it was the GAS Sleeping Beauty or the DL103S fitted on the G707 + DP1250, I was always rewarded by musically authoritative presentation - very dynamic and involving just like my idler-driven motor units. In hindsight, the many hours and $$$s I spent in the 80s adjusting and tweaking my AR/Merrill were futile. 😞 I could have just gotten a used KD500 or DP1250, sat back and enjoyed.😊

Denon DL103S

This reinforced what I had already discovered (but was in denial) in the late 80s. Aside from the superior speed stability of the Thorens TD124 drive system, the spring suspension + lower torque motor of a classic belt-drive turntable like the AR or TD150 slowed down transients and compressed dynamics.

Grace G707

I don't think I heard the fullest potential of the Grace G707 till now. This is a simple yet well designed precision-built instrument that just lets the virtues of any cartridge shine through.  Even if it is considered a low mass design, I do remember people using the Supex SD900 and Koetsu Black with this tonearm because of its fine tolerance bearings. At some point I will revisit the G707 mounted on my idler driven motor units.

Grace G540

Denon DP1250 + Grace G540L

My only beef with the G707 is its fixed head shell. Inconvenient when swapping cartridges, I replaced the Grace G707 with its pro-oriented sibling, the G540. As pictured, the G540 uses similar double gimbal bearings but has a higher mass "J" shaped tube, which can accept the Ortofon SPU derived SME standard head shell.

Rega R200

DP1250 + Rega R200

As I sank deeper into my direct drive initiation, I kept going through my LP collection and mounted another tonearm. This time, the Acos OEM'ed Rega R200 performed pretty much at par with its contemporaries, the Grace G707 and G540.

The inevitable

Although this Denon is not a top of the line model, a casual comparison to the Garrard 301 was inevitable.

Garrard 301 + Ortofon RMG309/SPU1s

 Unfortunately, the Denon plinth would not accommodate a spare SME 3012 I had on stand-by. The next best thing I could do to somewhat even out the playing field was cut another tonearm board for my Fidelity Research FR64fx.

Fidelity Research FR64fx

While the DP1250 and the Garrard 301 share a similar character of sure-footedness inherent in a stable drive system, the 301 does its job with less effort. There is a slight tendency to strain with the DP1250 on complex musical passages. If forced to split hairs, I also hear a trace of hardness and/or dryness on certain recordings which sounded more pleasing on the 301.

Denon DP1250 + FR64fx

In the past I found the FR64fx to sound more analytical compared to the SME 3009/3012 and Ortofon RMG309. Could the 301/SME 3012 combo be more euphonic while the DP1250/FR64fx more accurate?

Better late than never

Regardless of what I am hearing, this Denon DP1250 experience garnered my admiration and respect for the direct drive system such that I am inspired to probe direct drive motor units further.🍻