Japanese Idler-Driven Turntable Part 7: Kenwood PC350

Kenwood PC350 - a Japanese TD124 spinning a jazz tune!😉

This ca. 1969 Kenwood turntable adapted the Thorens TD124 drive system sans eddy current speed control.

The above specs were taken from audio-heritage.jp

The PC350 drive system

Here's what's beneath the heavy cast aluminum chassis

This turntable arrived well-packed and unusually very clean. I decided not to disassemble the 4-pole synchronous motor because it runs whisper quiet and rock steady at 1800 rpm.

Instead, I just added Mobil DTE 25 oil.

However, the thrust pads of the idler wheel pulley (left) and main bearing (right) were totally deteriorated. Since I had no idea what kind of material was originally used, I ordered teflon rods and made replacements as pictured above.

Main bearing size comparison (L to R) - Realistic Mark 7, Kenwood PC350 and NEAT P58H

After thoroughly cleaning all of the main bearing parts with lighter fluid (Naphtha), I reassembled and packed it with Phil Wood bicycle bearing grease.

This is the idler wheel pulley bearing assembly, which was also cleaned with Naphtha and lubricated with Phil Wood grease.

My only issue with this turntable is that it turns close to 1 rpm fast. Some internet sources claim it's due to the thickness of the belt. Using the thinnest belt from my Thorens TD124 belt collection (they all fit) + Phil Wood grease in the idler wheel pulley bearing (instead of DTE 25 oil) hardly made a difference. 

Hmm, I wonder if the cure is to actually trim down the pulley diameter a bit ?🤔? 

That's a very risky proposition though, so I'm keeping it as-is. Anyway, to my ears, the + 0.7 rpm is only critical when listening to classical music. As usual in this hobby, YMMV.

I immersed the felt washer at the bottom and at the top of the idler wheel bearing in DTE 25 oil.

The tiny knob adjacent to the tonearm pillar regulates the damping of the cueing device.

With a spindle to pivot distance = 219 mm, this high mass tonearm requires a cartridge + headshell weight of at least 28 grams! As featured in the videos at the beginning and below, it works well with medium to low compliance cartridges like the Nagaoka MP10, Supex SD900 MkIV and SPU #1s. I've also had good results with the Denon DL103 and Shure M3D.

Kenwood/Trio has an interesting history. Founded in 1946 as Kasuga Radio, Co. Ltd, and renamed Trio Corporation in 1960. "Ken-wood" was a trade name coined by William "Bill" Kasuga, who along with George Aratani and Yoichi Nakase, established an international distributorship network in the west coast in 1963. 

The company was still trying to carve its market share when the PC350 was manufactured. In less than a decade, the synthetic marble plinthed KD500 direct drive turntable affirmed Kenwood's position in the world of high fidelity. Having heard both turntables in my hifi setup, I prefer the TD124 clone sonically!😉

Vinyl Engine has good info about the Kenwood PC350 + other early models. Unfortunately, that website is currently not accepting new memberships.😔 Using a translation app, this Japanese audio blog has several entries regarding the very similar Trio KP7021, well worth visiting! 

Happy LP spinning!