[Review] Lencohell Corian Platters

Lencohell Corian Platters - LH-2 and LH-4

An easy Upgrade for Your Lenco

Product name: Lencohell Corian Platters - LH-2 and LH-4
Manufacturer: Lencohell - Italy
Cost: LH-2: 130 Euros, LH-4: 90 Euros (Currency conversion)
(YMMV)

Reviewer: Roger McCuaig - TNT Canada
Reviewed: October, 2018

Introduction

I really enjoyed doing this review. Something right in my wheelhouse as they say in baseball. Vinyl is my preferred music media and Lenco Idler drive turntables are my player of choice. So, reviewing a platter designed for Lenco idler units caught my interest immediately. I presently own 5 Lenco idler turntables, 2 in service and 3 others awaiting rebuilds. I also have rebuilt 3 others that have found new homes. It all started the day I found an L-75 for sale in a flea market for a very reasonable price. I brought it home, cleaned, adjusted and lubricated it and set it up beside my Pro-Ject RPM 9.1 / Speedbox II. The Lenco totally outclassed the Pro-Ject which I paid over $2000. Can. for. Even with the Speedbox II the belt drive unit couldn't come close to the Lenco in PRAT* and the precision of the attacks on notes. I sold the Pro-Ject and started collecting and rebuilding Lencos.

I was not aware of the existence of the corian platters under review here until we got the email from Lucio (our fearless leader at TNT-Audio). I immediately went to the web site and a quick read through was all I needed to decide that I wanted to try this. The web page is called Lencohell, clearly a wink at the long running web page Lencoheaven.net which I have been a follower of for many years. On the Lencohell web page one finds the following: “We are two friends from Italy. We are long time music and audio lovers. We have built much of our audio stuff.” It goes on the say “We don't love equipment. We love music.” My sentiments exactly, these are my kind of people. The web site was somewhat confusing to navigate at first but it didn't take too long to figure out the layout. The person who contacted TNT-Audio and who I dealt with throughout the review process was Giorgio Marchiori in Verona, Italy. It is my understanding that he is the mastermind behind the corian platter design.

The components received for review are the LH-2 corian platter with spindle extension and the LH-4 corian platter with no spindle. The ones I received are white however the web page indicates that other colours are available on request. Unfortunately, the LH-2 arrived broken, it clearly received a significant blow during the trip to Canada that was sufficient to break the press fitted assembly between the spindle extension and the base. It also caused a bit of chipping to the corian around the centre hole. The chipping was not anything that would harm in any way the performance of the platter once the spindle was replaced. I did have to wait quite a long time for the replacement spindle assembly to arrive. Clearly this part got hung up in Canada Customs, something that seems to be happening a lot lately! I was unable to do any testing of either product during that time as the LH-4 is too thick to use alone on my Lencos, the Lenco spindle not being long enough. As a consequence, I can test the LH-2 alone or the LH-4 on top of the LH-2 but not the LH-4 alone. Giorgio is going to have to find a better way of packaging the LH-2 for shipping otherwise I fear this spindle damage is destined to eventually occur again.

Lenco Anatomy vs heavy platters

It is certainly no secret that a very massive rotating platter has often been incorporated into the design of mid/high end turntables as a way to increase speed stability. (as well as a lot of other claimed benefits!) The L75/L78 turntables were marketed as “Transcription Turntable. The message being that they were designed for heavy use. Consequently, the drive motor is significantly larger than one would normally find in a consumer turntable. Therefore, although the original Lenco platter is rather hefty, these units can easily handle the additional torque demand associated with increasing the mass of the platter. A fact that has certainly not gone unnoticed by the armies of Lenco idler-drive owners who quickly discovered the use of stacked platters with spindle extenders on their favorite Lenco.

The whole mass of the Lenco platter is supported on the round end of the spindle that is sitting on a paper thin Nylatron thrust pad which is in turn resting on a metal thrust plate. The bottom of the spindle is of course sitting in oil. About 75% of the Lencos that I have disassembled have shown a significant dimple in the thrust pad. Possibly Lenco never imagined that these units would be still running in 2018 (at least not with the original thrust pad). All of the Lencos with dimpled thrust pads had an increase in system friction when compared to a normal (non-dimpled) pad. This can be detected by performing a free run-down test; tape down the platter brake, run the unit up to speed then turn it off a measure how many seconds it takes the platter to stop turning. Increasing the mass of the platter carries the unfortunate consequence of accelerating the dimpling of the spindle thrust pad so an alternative solution is called for. My solution was to replace the thin and soft Nylatron pad with a disc of Acetron which is a bit thicker than the original pad. Acetron has better wear properties than the original pad and has excellent characteristics for this application. Acetron rod can be purchase from industrial plastics suppliers for a quite reasonable price. I sliced off thin disks with a mitre saw and then used some sandpaper to get a smooth surface. My experience over a number of years is that the Acetron thrust pad has not dimpled and provides a long-term alternative to the original material without any addition of friction to the system. Although the Acetron pad is thicker than the original, the brass sleeve bearings still sit fine on the straight section of the spindle and perform perfectly.

Acetron vs Nylatron: (taken from an industrial plastics web site) Acetron is a copolymer Acetal plastic whereas Nylatron is a Nylon based product. Acetron is characterized by a low coefficient of friction and good wear properties, especially in wet environments. In high moisture and submerged applications, acetal bearings outperform nylon 4 to 1.

Therefore, using a more massive platter on a Lenco turntable requires one of the following modifications: replacing the spindle assembly with a more robust aftermarket unit, replacing the original thrust pad with something similar to the Acetron pad, or installing a new Nylatron thrust pad every couple of years.

The Test Procedure

The evaluation of the Lencohell platters was done in 3 parts:

Evaluation of the impact of the added mass on speed stability?
Evaluation of the impact of Corian on the tone vs the benchmark acrylic mat?
What is the overall impression of this product? Is it worth the investment?

Step 1: Added mass vs speed stability
Many people believe that moving the operating point higher on the drive motor's torque curve leads to a more stable system. There are of course two ways to accomplish this; by increasing the rotating mass or by increasing the friction of the system. Adding mass to the platter increases the angular momentum of the system thus increasing speed stability. (remember Newton!) In my opinion, adding torque demand by increasing the rotating mass will have a more positive impact on the speed stability than adding torque by increasing the system friction. One can find a lot of debate on this subject on the web, feel free to dive in.

I use a 12-inch acrylic strobe platter to check the speed on my turntables as I have found it to be the most reliable method. I tried using an App on my Android phone but found it to be not accurate enough. Giorgio Marchiori (Lencohell) came to the same conclusion. The testing was performed on two Lenco idler drive turntables. TT1 is a partially rebuilt L75 with the original Lenco tonearm. The plinth on this unit has been screwed into a 1.5-inch-thick base made of Baltic Birch plywood. TT2 is a fully rebuilt L75 with a Dynavector DV507MKII arm on a 70-pound Baltic Birch plinth. Of course, adding the Lencohell platters requires a very large amount of raising of the tonearm to get to the correct VTA. (vertical tracking angle) Luckily, both the original L75 arm and the Dynavector arm had enough range to accommodate the required adjustments. This certainly may not be the case for all tonearms and warrants careful investigation before purchasing any add-on platters. The result looked pretty weird, the tonearms looked like a construction crane! However, they both performed well under these abnormal conditions. Certainly, the long-term alternative would be to raise the tonearm base.

The test procedure consisted of running the TT up to speed and examining the speed stability visually using a full platter diameter, good quality, acrylic stroboscopic disk. This test was performed first with the original Lenco platter alone, then with the LH2 on top of the original platter and finally with the LH2 plus the LH4 on top of the original platter. Note: my acrylic mat was removed for all of these tests.

Step 2: Lencohell Corian material vs the TMIOTT acrylic mat.
Again, the testing was performed on both turntables. For each unit:

TMIOTT acrylic mat on Lenco platter.
LH-2 on Lenco platter.
LH-2 + LH-4 on Lenco platter.
All tests were done at constant volume and the VTA and VTF were carefully adjusted for each new setup.

Step 3: Overall performance – how does it sound?
This one is pretty much self-explanatory. Both TT's were used and a several records played in the three configurations listed in Step 2 in order to determine the impact on the overall sound.

The Results

Step 1: Added mass vs speed stability
A lot of work has been done on my Lencos to improve their performance and speed stability. The list of repairs, adjustments and modifications is too extensive to include here. Suffice it to say that speed stability is quite good. On my Lencos, the strobe bars freeze under the 60 hz lighting and the bars do not drift. However, if one focuses on one specific bar it can be seen to move +/- one bar a couple of times per second. For lack of a better idea I am calling this “jitter”. After some deep though on what this jitter actually represents, I have concluded that it must be due to very small amplitude, short duration, speed variations. Call it a micro variation inside a constant macro speed.

So, does this jitter have any effect on the sound? Will the LH-2 and LH-4 have any effect on this jitter? I don't know, let's find out. The test results were pretty much identical for both turntables. Adding the LH-2 slowed down the RPM slightly so it required a bit of adjustment of the Lenco speed calibration screw. Adding the LH-4 on top of the LH-2 had the same effect but to a lesser amount. There was no problem adjusting the platter back to the correct speed with the additional weight on top. Adding the LH-2 produced a small reduction in the amount of jitter however adding the LH-4 on top of the stack produced significantly more reduction in the jitter.

In summary, both Lenco units tested performed well with the added mass on the platter and no ill effects were noted. It was easy to compensate for the slight drop in platter speed caused by the addition of one or two additional corian platters. Adding one platter resulted in a small reduction in platter jitter whereas adding the two platters produced a larger effect.

Step 2: Lencohell Corian material vs the TMIOTT acrylic mat
The corian test was found to produce a slightly brighter sound than the TMIOTT. Overall, I preferred the sound vs the acrylic mat. However, I think it needs to be noted here that it is quite difficult and possibly impossible in this test to differentiate between the effect on the sound due to the corian material and the effect due to the added mass. My past experience testing different mat materials typically produced significant changes that were easy to perceive. Not in this case. I am unable to conclude that corian sounds different than acrylic.

Step 3: Overall performance – how does it sound?
My listening notes read “overall sounds great”. I think the word “overall” is the key. The sound was more natural and effortless. Reviewers, often write about speakers that disappear. I got the impression that the turntable disappeared. Now I should clarify that I am referring to the heaviest setup, the stacked LH-2 + LH-4. I wasn't getting this feeling with the LH-2 alone. These results were more prevalent on TT1, the unit running the original L75 tonearm with a Dynavector XX-2MKII. This combination really came to life and never sounded so good. Is this the result of adding the corian stack or of setting the tonearm significantly higher off the table or a bit of both? It is impossible to say without additional testing however I suspect it is mostly the former.

Conclusions

Adding a significant amount of mass to a Lenco turntable platter can improve its performance. In this case it took stacking both the LH-2 and the LH-4 in order to obtain the maximum improvement. The results were more noticeable on one of the two turntables tested. The two most important differences between these two units was that unit TT2, the one that was less affected, had a much more modern and expensive tonearm and a much heavier plinth. Both units had modern high-end cartridges and quality headshells. (The original headshell on TT1 had earlier in the year been replaced with an aftermarket headshell) No difficulty was encountered in readjusting the speed of the TTs to compensate for the additional mass and they ran perfectly with the added mass. Anyone contemplating adding this much mass to the platter should seriously consider upgrading the Nylatron spindle thrust pad. It is important to consider that all of the testing was done on turntables that had been fully cleaned, lubricated and adjusted, and had new, or like-new, spindle bearings. The products tested might not give the same results on a unit bought at a yard sale and ran as is.

The Lencohell corian platters are well made, look good, and do the intended job well. Given the crazy prices being asked for audiophile upgrade components these days, these platters are reasonably priced. I am sure Lencohell is not getting rich from selling these units. Certainly worth consideration for those who wish to implement a quick and easy upgrade to improve the performance of their idler drive turntable.

(*) PRAT means Pace, Rhythm and Timing.

Note: All photos were provided by Lencohell. No photos of the actual test setup are available as the turntables were packed up for moving.