SP-10 mkII, the next project

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IMO, increasing the mass of the platter is the biggest bang for the buck.

I have had very good success with a mat I picked up for my SP-10 mkII that consists of 5 layers -- from bottom to top: Delrin, copper, damping (glue?), copper, carbon fibre and lacquer. This mat is 9 pounds, so the combined weight of the platter and the mat is much closer to the mkIII. There was a SIGNIFICANT improvement to the sonics.

A buddy of mine simply tried two copper mats on top of his SL-1200. He says it worked "very well" and made a number of significant improvements over just using a single copper mat.

Oyaide makes a 2mm thick silicon mat that could fit in between the two mats as a damping layer... this has not been tested.

That's another tweak I'd like to try. Heavy (copper) platter mats. In good time I will.

Some things to consider when increasing the platter mass;

1:Increased bearing wear at the thrust point

2:Is the bearing shaft itself of a large enough diameter to support significant increases in load? Probably there is a load level where audible improvements are negatively offset with increased wear and tear on the bearing. And then an even greater load level where there are no audible improvements to be heard, but damage to the bearing happens immediately. I suppose this level can be found by trial and error. But I'm not going there.

Would it be of interest to examine the heat generated at the cap and bearing as evidence of friction? Just a thought...would be hard to measure I suppose. Would probably be best tested using a rig of some sort I suppose. Could also check for expansion and contraction of the material. Probably negligible and unnecessary.

Yeah. And maybe this could be implemented fairly easy if one had some sort of optical thermometer. Industrial strength. Even better, an optical thermometer that could see through the metal of the bottom bearing end cap and get a read on either the bearing ball, the thrust cap, the shaft and the bushing surfaces separately. And I've no idea about where to look for one with these capabilities. And no idea about costs of such an instrument. I've seen hvac techs walking around with hand held thermometers that they simply point at a device to read its operating temperature.

But it is still useful to observe and (consistently) measure indications of wear at the thrust cap after a given amount of use.

-Steve
 
4203 Torlon cap after 1 week

DSC_0365.jpg

This plastic is difficult to focus on. But there is evidence of a dimple.

next: the same three test tracks but after 1 week of normal use.

4203_300_2.jpg

above: 300 hz @ plus 12db. HFN 001

4203_bassdrum_2.jpg

above: bass drum track........Shure TTR 110

SG_4203_2.jpg

above: Silent Groove track........HFN 001

It is reporting similar to the 4301 Torlon cap, imho.

-Steve
 
A new Delrin replacement thrust cap

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Above two images: On left; the new Delrin thrust cap. On right; the original nylatron thrust cap. The Black Delrin machines much softer than either of the Torlon materials. (4203 and 4301)

DSC_0366.jpg

above image: The Delrin cap rests on the shaft knob end. But is not fully installed.

DSC_0367.jpg

above image: The Delrin cap after being seated onto the shaft.
Assembly note: ID size on the Delrin is closely size for size with the knob end. But it pushed on with no effort. This indicates that the Delrin has some elasticity, especially in comparison to the 4203 Torlon which demonstrated no elasticity.

Test Tracks for the newly installed Delrin cap:
Delrin_300_1.jpg

Above: 300 hz @ plus 12db......HFN 001

Delrin_bassdrum_1.jpg

Above: Bass Drum track.........Shure TTR 110

SG_Delrin_1.jpg

Above: Silent Groove track........HFN 001

See anything different this time?......I do. In particular look at the silent groove tracks and compare to every previous SG plot. The only difference between them; Delrin cap.

I'd say the Delrin measures quieter except at the 60 hz level which is an artifact of the test record and has not changed. But on either side of 60 hz all frequencies report much, much lower noise levels.

Yeow

-Steve
 
Is this because the Nylatron cap has a recess and the delrin is flat?

After one week of normal use let's see what the Delrin cap looks like and reports like. Otherwise, I've no idea.

fwiw, listening does reveal some positive attributes not previously heard. Mainly, lower background noise, better definition of fine details. What you'd expect. Not huge. But identifiable.

-Steve
 
Have you tried a Silicon Carbide ball or other ceramic bearing?

Not yet. First I measure the different caps over the standard bearing ball.....which is still in usable condition. Then later I will try some different bearing balls. In addition to the silicon ceramic ball I'll likely try one in tungsten carbide. Perhaps different grade levels should be considered. (I think I've already stated this earlier....but the thread grows longer and becomes a chore to read through.)

One thing I'll look for, in addition to noise levels, is wear rates on different cap materials. Example, silicon ceramic ball against a Delrin thrust cap. I'd expect a higher wear rate there, but will attempt to keep the process methodical enough to either confirm or debunk that intuitive hunch.

-Steve
 
How can a differerant ball material make any differance when it`s working on a soft material as Nylon or Delrin ??.

The "how" is more difficult to answer than the "why". So I'll handle the why of it. answer: On the web......it's become a popular tweek to swap out original hardened steel bearing balls with one of the newer tech silicon ceramic variety. Google up the key words " ceramic bearings" and see what comes up. The "how" of it is answered somewhere within that search result.

Audiophiles tend to report improved sound quality when replacing a normal thrust bearing with one of the newer silicon ceramic bearing ball. That's all I know.

Fwiw, I've tried ceramic bearing balls in a couple of different project tables. First in my Teres platter bearing. On the Teres I'd also used a hardened tool steel bearing ball, a tungsten carbide ball, and then the ceramic ball. And at one point a brass bearing ball. The brass was a failure that resulted in rapid wear of the ball itself when it became evident that the shaft was rotating over an unmoving brass ball at its contact point within the bearing shaft counter bore. Why the ball remained motionless against the Delrin pad I'm not certain of. The Teres bearing assembly sheet instructs the user to insert enough lube within the cavity of the bearing shaft counter-bore to ensure a liquid vacuum that retains the bearing ball within it. Failing this, who knows what might happen.

Regardless, the differences I heard between the different ball types on the Teres was difficult for me to assess. Very slight. I think, in the end, I went back to the tungsten carbide ball. It is posible I saw better thrust pad wear with that ball.

TD124. I'm using a ceramic bearing ball in my 2729 (sn) mk1 unit right now (at the main platter bearing). Also I have a ceramic bearing ball at the thrust end of the E50 motor. It doesn't seem to hurt anything. But I don't recall hearing any big differences using different bearing balls at either thrust point on the TD124.

-Steve
 
Audiophiles tend to report improved sound quality when replacing a normal thrust bearing with one of the newer silicon ceramic bearing ball. That's all I know.

-Steve

Yes,
I could agree with that if the thrust ball bearing was turning on a very hard surface.
In my opinion, only then the harder ball bearing could certainly lower rotational friction.
I`m not saying one shouldn`t use ceramic ball bearings in this case,it wouldn`t degrade the preformance if the ball surface is finely polished.
 
Delrin Cap 1 week out

DSC_0404.jpg

Above: Delrin thrust cap after 1 week of normal playing.

Next: Test plots of the Delrin cap after 1 week.
Delrin%20300%201wk.jpg

Above: 300 hz at +12 db........HFN 001

delrin%20bdrum%201wk.jpg

Above: bass drum track .......... Shure TTR 110

Delrin%20SG%201wk.jpg

Above: silent groove track ......... HFN 001

Hmmm. Lets compare the before and after on the silent groove plot.
SG%20delrin%20b4_aft.jpg


Above: Delrin cap silent groove plots. Left is taken as a fresh install. Right is taken after 1 week of normal play. The Delrin cap after 1 week looks like all the rest. I can't explain this. I would have expected the Delrin cap to continue producing the same result with or without the small evidence of wear seen in the top photo.
No explanation except to suspect that something not yet considered has to explain the fresh install plot. Like maybe the fresh install was not making full contact between cap and ball. Maybe floating on a thin film of oil? Just a guess.

Anyway, I'll continue. The 1 week SG plot appears to closely compare to all previous SG plots except the one.

-Steve
 
It seems to me the answer is in this picture..If you inspect the delrin cap you see some irregularity from flat at it`s center, this has it`s indication by the way the ball bearing left it`s mark, the dimple seems like a two stage cavity,one made by friction the other from caving in.
 

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It seems to me the answer is in this picture..If you inspect the delrin cap you see some irregularity from flat at it`s center, this has it`s indication by the way the ball bearing left it`s mark, the dimple seems like a two stage cavity,one made by friction the other from caving in.
DSC_0363.jpg

If you are referring to the dimple at center of the Left cap in the photo, that dimple is actually an artifact of the machining method. (Nothing to do with wear or being used.) All surfaces on the caps I'm producing are generated by single point turning. When making face cuts on a lathe it is not unusual to have a little nib at center where the cutting speeds are so slow as to result in the last little bit remaining stock at the center breaking off rather than cutting off.

Steve
 
MDS filled Nylon thrust cap

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Above: looking at the inside....the new MDS Nylon cap on the left. Original Nylatron cap on the right.
DSC_0403.jpg

Above: looking at the outside....replacement cap left, original cap right.

Surface finish is rough on the OD. My fault. Wrong cutter. Parts are so small I have to view them through a magnifier before I can determine surface finish levels. fortunately the finish levels on the interior of the cap is adequate for the purpose. And, really the surface levels on the face that makes contact with the thrust ball is just fine. Flat and parallel to the opposite surface at the inside.

Next: mounting
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Above: looking at the shaft knob end just for reference. No change. It appears the same as it has been since I've owned it.

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Above: resting over the knob but not yet seated.

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Above: New nylon cap seated.

The MDS nylon is a formula with a lubricating element added to it. Molybdinum Disulfide. It is said to provide significant lubrication to the nylon for operating in a bearing application. That seems appropriate to our application.

After assembly test plots:
Nylon_300.jpg

300 hz at 12db.......HFN 001

Nylon_bdrum.jpg

Bass Drum.....Shure TTR 110

Nylon_SG.jpg

Silent Groove track.......HFN 001

The above 3 test plots appear to conform to the tests we've seen so far....except one.

-Steve
 
Plinth design

Nice work user510.

I recently bought a Panasonic SP10 with a wooden plinth and SME3009. It's my first DD turntable and a like the punch in the lower end compared to earlier Thorens and Aristone player.

I have an idea for plinth design. I call it Qboard.(Qboard | Qln). I have build speaker with this material for over 30years and it work great. It should also work well to make a plinth with this material.
It's a sandwich design with a viscoelastic glue between.(just to be clear, I have no commercial interest is this issue. It's just for fun). Material can be wood, metal, Corian...
This can also be made in several layer.

I have plans to make a new plinth in this material.

Have you compared sound to your TD124?
I have a TD124 with SME3012 that I have to restore motor on. So I'm curious.
 

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Nice work user510.

I recently bought a Panasonic SP10 with a wooden plinth and SME3009. It's my first DD turntable and a like the punch in the lower end compared to earlier Thorens and Aristone player.

I have an idea for plinth design. I call it Qboard.(Qboard | Qln). I have build speaker with this material for over 30years and it work great. It should also work well to make a plinth with this material.
It's a sandwich design with a viscoelastic glue between.(just to be clear, I have no commercial interest is this issue. It's just for fun). Material can be wood, metal, Corian...
This can also be made in several layer.

I have plans to make a new plinth in this material.

Have you compared sound to your TD124?
I have a TD124 with SME3012 that I have to restore motor on. So I'm curious.

Speak, that is a nice plinth. Do you know what veneer/wood that is?
 
@ Speak

I suspect that your SP10 is the original model which has a different motor to the MK11 which is the subject of most SP10 threads. It has many differences including a less powerful motor. But Panasonic soon made substantial changes when they introduced the MK11. [The very rare MK111 - which is frighteningly expensive to buy even if you do find one is again very,very different to yours and the MK11.]
 
MDS Nylon cap 1 week after

Perhaps it's not the thrust plate that matters? Maybe a ceramic ball would make a difference?

Thrust ball material is on the list for testing. See reply #247. I want to keep this methodical. It is slow going. But when I have enough test samples I can post a summary of the testing which should be helpful in finding out ( at least in part) what works for an SP10 mkII bearing.

On to the next thrust cap:
MDS Nylon after one week of normal use.
DSC_0452.jpg


That's a fairly pronounced wear dimple.
When I summarize on all of these thrust cap materials I will report dimple diameters on each cap for the one week interval. At present I have a loupe with reticle that allows measurement resolution to .005 inch graduations. Unfortunately I can't snap a photo of these. But I will report each value in the group for comparison.

Test Record Tracks after 1 week. MDS Filled Nylon
Nylon%20MDS%20300_2.jpg

300 hz at +12 db.........HFN 001

Nylon%20MDS%20bdrum_2.jpg

bass drum track......... Shure TTR 110

Nylon%20MDS%20SG_2.jpg

silent groove track..... HFN 001

The next post is on to the next cap material.

-Steve
 
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