Japanese Idler-Driven Turntable Part 5: Lafayette PK300

I bought this Lafayette PK300 idler-driven turntable because it looked like an improved Shield MO-19 (aka NEAT P58H) with the added feature of an eddy current pitch control as found in the Garrard 301/401 and Thorens TD124.

Shield MO-19 vs. Lafayette PK300

Comparing them side by side, the PK300 turned out to be proportionately smaller in all dimensions and lighter in weight. Hmmm🤔…let's travel back to the late 50s.

from page 37 of the 1957 Lafayette Radio Catalog

Based on the 1957 ads above and below, the PK300 preceded the Lafayette PK245 featured in Part 3 of this series. 

Lafayette PK300 ad in the October 1957
issue of High Fidelity

The PK245 appeared in the 1958 (p.12) catalog and was last seen in 1960.

Top = Argonne P38 strobed platter
Bottom = underside of a NEAT TP50

After sifting through several pictures on the internet, I realized that the Argonne P38 and NEAT TP50 shared the same 3 lb strobed platter, motor, main bearing, and practically the same chassis, with the PK300.

Except for the pitch control location and the P38/TP50 chassis' symmetrically elevated left side, they are mechanically identical. Click here for more pictures of the Argonne P38 turntable at AudioKarma. 

Since the 1960 NEAT General Catalog was the only source I could avail of to establish the NEAT P58H's age, I'm presuming that the Argonne P38/Lafayette PK300/NEAT TP50 were its predecessors since they had less sophisticated engineering design elements, as we will see further below.

More sleuthing to come...so let’s take a break with Pat Metheny.

The NEAT DNA and so forth...

Under the platter, the common genes shared between the NEAT P58H and Lafayette PK300 are evident. But as soon as we take a deeper dive into the details, differences unfold. 

As I mentioned in Part 2 of this series, the NEAT P58H is equipped with a grease lubricated main bearing, while the PK300 has an oil bearing type. Dimensions aside, the PK300 and Realistic Mk-7 main bearings are cousins.

Lafayette PK300 main bearing components vs. the Realistic Mk-7

under the chassis

Compared to the more evolved P58H, the PK300 employed a simpler and less substantial speed/motor/pulley/idler wheel selector mechanism.

Even if this is a 4 pole single phase induction type AC motor with an eddy current disc + magnet, the cleaning and servicing procedure is the same as the AC hysteresis type, so please click back to the NEAT P58H page. 

Motor wiring diagram of the Lafayette PK300

When I acquired the PK300, upon turning on the motor, vibration was immediately apparent at the headshell lift because the motor subchassis was firmly mounted to the chassis with stacks of rubber grommets. So I replaced the rubber grommets with springs of similar compliance to those used on the NEAT P58H. The springs were a bit of an improvement but other mechanical components under the chassis were still vibrating, perhaps because the motor vibration wasn't completely being absorbed.🤔

RPS 426-0001 shock mounts from Surplus Sales of Nebraska

Given the marked difference in the speed/motor/pulley/idler wheel selector mechanism I noted earlier, I surmised that the simpler PK300 required motor mounts that have a spring rate compliance in between the P58H springs and rubber grommets. As an experiment, I removed the springs and installed my spare set of rubber shock mounts for the Gray Research turntable. Voila! No more extraneous vibrations + speed stability improved.👍 

The same shock mounts also resolved a similar issue I had with the Lafayette PK245.

Before buying out the entire stock of RPS 426-0001 from Surplus Sales of Nebraska for your Japanese idler-driven turntable refurb biz, please be advised that this particular rubber shock mount isn't a panacea. It made the NEAT P58H rumble like a locomotive! 

To get a sense of PaceRhythmAndTiming idler-drives are known for, let's spin an 80s synth-pop track. 

Enjoy! 😎