Saturday, March 4, 2023

Japanese Idler-Driven Turntable Part 2: NEAT P58H/Shield MO-19



In the early 2000s, the swinging tonearm mount of the Shield MO-19 caught my attention because it looked like the perfect partner for my Velvet Touch viscous damped tonearm. It turned out that this Japanese 4-speed idler-driven turntable is actually a rebadged NEAT P58H. 

Its performance exceeded my expectations! So instead of relegating it exclusively for mono hifi playback duties, I also enjoy using it fitted with high quality tonearms like the Audio-Technica AT1501-IIDenon DA305, Grace G540LFidelity Research FR54 and others for stereo LPs.

I got this NEAT P58H + Tokyo Sound ST900 tonearm when Tish and I returned to the States in 2016. It wasn't as well kept as the MO-19 and required a bit more fettling. 

The turntable is built on a heavy duty cast chassis with a 1.5 kg cast aluminum platter. Aside from a few discussions in audio forums, the only literature I've found about this particular model is the 1960 NEAT catalog available for download at vinylengine.com.

Everything I've done to my NEAT P58H and Shield MO-19 is documented below. 

Idler wheel + idler arm

The rubber on this NEAT P58H idler wheel was in good condition except for a pinch, which couldn't be removed by minor grinding. So I sent it to Terry E. Witt for new rubber.

Terry of Terry's Rubber Rollers did a great job rejuvenating the P58H idler wheel (above left) + another wheel for my ROK L34 Rondine Jr

Idler wheel installation sequence

The idler wheel should spin freely and quietly after a drop or two of blue 3-In-One SAE 20 motor oil

Idler arm reassembly sequence

The idler wheel arm action should be snappy. If it isn't, back off the nut a bit and/or add a bit of light oil to the sliding surfaces.

A good balance between speed accuracy, torque, and low noise can be achieved by adjusting the idler wheel contact pressure to the inner rim of the platter.


Unplug the turntable from the AC source and manually spin the platter CW or CCW. The platter should gently stop when the speed control knob is turned to any of the speed settings as the idler wheel engages the inner rim of the platter. If the platter stops abruptly or doesn't stop at all, go back to the preceding procedure and adjust the idler wheel position on the idler arm accordingly.


60 Hz pulley dimensions +
red arrow indicates the pulley's set screw for height adjustment

While the turntable is disconnected from the AC source and the speed selector set at 33 rpm, I set a 1-1.5mm clearance so that the idler wheel doesn't touch the shoulder of the 45 rpm step.

Speed Selector Mechanism

With the speed selector at the 78 rpm setting, make sure there's no clearance between the tip of the set screw and the piston which raises and lowers the idler wheel arm mechanism.

Before we move on, how about a track from Style Council?

Motor


The turntable is powered by a fairly substantial 4-pole hysteresis synchronous motor. 

It's not as hefty as American-made Ashlands and Bodines, but bigger than the TD124's E50 and comparable to those fitted to the Garrard 301401, and the ROK B12GH's Papst Aussenläufer

 Through the years I've gotten requests for a schematic because some of these turntables were hastily pulled out of installations by flippers for quick bucks on eBay. 


Spring suspended motor = less vibration

Top view of the motor + sub-chassis

The deteriorated bottom rubber mounts (red arrows) can be replaced with rubber grommets

To remove the motor, unsolder the motor wires from their respective connections. Use my hand drawn schematic above as a guide. Then, remove the four nuts marked with blue arrows.

Before pulling out the motor entirely, I marked its orientation (black arrows) in the sub-chassis for easier reassembly.


To disassemble the motor, remove the four nuts marked by the yellow arrows.

Motor parts ID

The top and bottom shells house the sintered bearing well and are almost identical in construction except for an exit hole on top for the motor spindle. I marked the partially visible sintered bearings (or bushings) with blue arrows. To access the bearings for cleaning, remove the spring clips marked with green arrows. 


As shown in the picture above, the bottom shell has a thrust pad. I clean sintered bearings by soaking them in solvent, either lighter fluid (Naphtha) or isopropyl (91% or greater) alcohol (IPA) overnight. For lubrication, I use blue 3-In-One SAE 20 motor oil

The parts inside the bearing well are numbered in sequence for reassembly.

To access the motor bearing, remove the bottom cover, which is held by three small screws + lock washers. Be careful not to lose the tiny 3mm ball bearing. Clean all the components with either Naphtha or IPA. The numbers indicate the sequence for reassembly.

The motor should now be whisper quiet in operation.

Let's take a break and hear a tune from Sinatra at the Sands LP.


Main Bearing


Just like the Shield MO-19, I also found old grease at the end of the threaded bottom cap of the main bearing of the P58H. The lack of an oil seal in the threaded bottom cap further confirms that this is a grease bearing design.

These are the main bearing components after cleaning (soaked in solvent overnight). They're ready for fresh grease and reassembly. I used Phil Wood grease left over from my Raleigh 20 restomod folding bike project

The Garrard 301 grease bearing makes the NEAT P58H bearing look diminutive.

CODA

Although innovative in its own right, the various pictures show that the mechanical design and manufacturing quality of the NEAT P58H/Shield MO-19 isn't quite as sophisticated as the illustrious Garrard 301, 401, or Thorens TD124. I never envisioned it to equal those revered models in terms of performance. However, IMHO and experience, a reconditioned NEAT P58H is a worthy alternative to a restored Lenco or Rek O Kut.


A nice ballad from Dexter Gordon's album Go brings us to a close.

HAPPY LISTENING!


Back to Part 1






6 comments:

  1. Hello,

    You still release awesome posts.

    Do you have information of KS Musicmaster turntable with VL series?

    Thanks & best regards,

    ReplyDelete
    Replies
    1. Thanks for the kind words!

      Does it look like this? https://2.bp.blogspot.com/-x1lIAZwMPHE/VeuXu91ulDI/AAAAAAAAEHg/6HXRBSZPBCk/s1600/DSCF5048.jpg

      That KS Musicmaster belongs to my friend Joey of Harana Audio in Manila - https://jelabs.blogspot.com/2015/09/harana-audio-listening-room.html

      Although I never had a chance to compare them head to head, I think it's at least as good as the NEAT P58H. Since I'm a musician the eddy current/pitch control of the KS Musicmaster is a plus!😊

      I have a lesser Musicmaster which, as far as I can tell, has a similar motor, drive train and eddy current brake. But the chassis and platter (rings like a bell) are made from pressed steel. Unfortunately, I got it with missing parts and wiring harness, gone.😞

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    2. Hello,

      I've found KS VL-707 that has bakelite platter and it's belt driven turntable.

      Hard to find information :(

      Delete
    3. Sorry, no experience with that model at all.

      Good luck in your search!

      Delete
  2. Thanks for all these gems from the past!

    ReplyDelete
    Replies
    1. My pleasure! A couple more Japanese idler drives are in the works.

      Delete