Looking at the first Torlon Thrust Cap
Above two photos: The new Torlon 4301 thrust cap on the left with the original Nylatron thrust cap on the right.
Next: checking the new for size.
Checking the thickness of the thrust pad. The standard cap showed a thickness of .8mm (or .0315 inches). So that was the nominal target. This new sample shows the thickness at .038 inches (.96 mm) An extra .008 inches of thickness at this feature seems ok to me.
Checking the outside diameter
Checking length
Setting the Mahr gage. The nominal value can be read on the micrometer readout. The Mahr gage (analog) is set to read zero at nominal. Deviation from nominal is seen as either positive or negative in inches. This particular Mahr gage is very sensitive. Its finest graduation is 50 millionths of an inch. that's .00005 inches. (or five hundred thousandths of an inch) When the dial shows a value of either +10 or -10 that is a thousandths of an inch. (.001") Left of zero is plus. Right of zero is negative.
I read this as .0003 inches over nominal.
Next: The fit
Next: Test record session. I'll report that in my next post.
-Steve
Above two photos: The new Torlon 4301 thrust cap on the left with the original Nylatron thrust cap on the right.
Next: checking the new for size.
Checking the thickness of the thrust pad. The standard cap showed a thickness of .8mm (or .0315 inches). So that was the nominal target. This new sample shows the thickness at .038 inches (.96 mm) An extra .008 inches of thickness at this feature seems ok to me.
Checking the outside diameter
Checking length
Setting the Mahr gage. The nominal value can be read on the micrometer readout. The Mahr gage (analog) is set to read zero at nominal. Deviation from nominal is seen as either positive or negative in inches. This particular Mahr gage is very sensitive. Its finest graduation is 50 millionths of an inch. that's .00005 inches. (or five hundred thousandths of an inch) When the dial shows a value of either +10 or -10 that is a thousandths of an inch. (.001") Left of zero is plus. Right of zero is negative.
I read this as .0003 inches over nominal.
Next: The fit
Next: Test record session. I'll report that in my next post.
-Steve
Torlon 4301 testing
With the Torlon 4301 thrust cap installed. The same three test tracks for comparison.
Above spectrum plot: 300 hz @ plus 12 db HFN 001
Above spectrum plot: Bass Drum track Shure TTR 110
Above spectrum plot: Silent Groove (rumble) track HFN 001
Next we should compare these to the previous reported tracks (same tracks) while using the standard and moderately worn Nylatron thrust cap.
Nylatron:
Above: Nylatron 300 hz @ plus 12 db HFN 001
above: Nylatron Bass Drum track Shure TTR 110
above: Nylatron silent groove track HFN 001
If we look closely at the silent groove track plots between the Torlon and Nylatron we see that the Torlon is slightly noisier. Not by much. what do you think?
-Steve
With the Torlon 4301 thrust cap installed. The same three test tracks for comparison.
Above spectrum plot: 300 hz @ plus 12 db HFN 001
Above spectrum plot: Bass Drum track Shure TTR 110
Above spectrum plot: Silent Groove (rumble) track HFN 001
Next we should compare these to the previous reported tracks (same tracks) while using the standard and moderately worn Nylatron thrust cap.
Nylatron:
Above: Nylatron 300 hz @ plus 12 db HFN 001
above: Nylatron Bass Drum track Shure TTR 110
above: Nylatron silent groove track HFN 001
If we look closely at the silent groove track plots between the Torlon and Nylatron we see that the Torlon is slightly noisier. Not by much. what do you think?
-Steve
My method is to run the sample thrust cap for one week, then test. Then replace with the next candidate.
Presently I'm spinning vinyl on it. Soundwise, I hear nothing obviously different.
We'll see how it wears over a week.
-Steve
PS: if you are in dire need I can cut one for you to tide you over 'till I have a good assortment of sample test results.
This is even better than expected.
Based on your test reports, I concur with your listening test. I don't think we will be able to hear any difference.
But it will be interesting to find out the measurement after one week.
2nd Thrust Cap
Monday is the day. I'll remove the 1st Torlon thrust cap and check for wear. But not until I've recorded the 3 test record tracks and charted them.
Following that I have another thrust cap to put in. This one is another Torlon cap. This time it is Torlon 4203. This material seems quite different from the 4301 Torlon. Not only is the color different, but the cutting properties are very different. The 4203 cuts harder and produces some wear on my carbides and high speed lathe tools.
Above photos: Left: 4203 Torlon.........Right: original equipment Nylatron
moving along...
-Steve
Monday is the day. I'll remove the 1st Torlon thrust cap and check for wear. But not until I've recorded the 3 test record tracks and charted them.
Following that I have another thrust cap to put in. This one is another Torlon cap. This time it is Torlon 4203. This material seems quite different from the 4301 Torlon. Not only is the color different, but the cutting properties are very different. The 4203 cuts harder and produces some wear on my carbides and high speed lathe tools.
Above photos: Left: 4203 Torlon.........Right: original equipment Nylatron
moving along...
-Steve
I'm using 20 wt turbine oil in the bearing housing. afik none of the cap materials I have on hand can operate without the addition of bearing lube.
Although I have some nylon on order that is described as having some libricant properties in its make-up but is not recommended for dry running.
-Steve
I am impressed with your work Steve!
I follow you tests of the thrust caps you are manufacturing with great interest.
In the meantime I have done som work on my SP-10.
I have added a bottom which is inspired by the Albert Porter design to my old plinth.
The old plinth is a constrained layer Construction consisting of top layer of corian and then several layers of aluminium, mdf and hdf. I have now added two layers of birch and oak Wood, and there is also a brass rod which drains the bearing into a heavy steel block.
[/IMG]
It sounds really nice with an unmodified Rega 250 and Goldring 1042 pickup.
Next step is to get the 12 inch Moerch mounted!
Regards
Nils
I follow you tests of the thrust caps you are manufacturing with great interest.
In the meantime I have done som work on my SP-10.
I have added a bottom which is inspired by the Albert Porter design to my old plinth.
The old plinth is a constrained layer Construction consisting of top layer of corian and then several layers of aluminium, mdf and hdf. I have now added two layers of birch and oak Wood, and there is also a brass rod which drains the bearing into a heavy steel block.
It sounds really nice with an unmodified Rega 250 and Goldring 1042 pickup.
Next step is to get the 12 inch Moerch mounted!
Regards
Nils
1 week after (4301 Torlon)
Torlon 4301 thrust cap
The dimple in the center of the thrust pad results after 7 days of normal play. A few hours or more each day. But not 24/7.
Same three test record tracks after the above noted 7 days.
Above: 300 hz test track from HFN 001
Above: Bass Drum track from TTR 110
Above: Silent Groove from HFN 001
Check the silent groove chart at 100 hz. At appears to have gotten quieter. Right after installation 100 hz was a few decibels louder at -58db. Now it reads -61db.
Other small differences.
Note: The 4301 Torlon did cut like it was fairly soft material.
-Steve
Torlon 4301 thrust cap
The dimple in the center of the thrust pad results after 7 days of normal play. A few hours or more each day. But not 24/7.
Same three test record tracks after the above noted 7 days.
Above: 300 hz test track from HFN 001
Above: Bass Drum track from TTR 110
Above: Silent Groove from HFN 001
Check the silent groove chart at 100 hz. At appears to have gotten quieter. Right after installation 100 hz was a few decibels louder at -58db. Now it reads -61db.
Other small differences.
Note: The 4301 Torlon did cut like it was fairly soft material.
-Steve
2nd Thrust Cap (4203 Torlon)
Above: 4203 Torlon cap is mounted.
I should note that this cap is the 2nd 4203 cap I made. The 1st 4203 (yellow Torlon) was cut with the ID a few 'tenths smaller. Actually, it was .0006 under nominal shaft size. and it would not fully seat over the knob end of the bearing shaft. So I cut another one. The one in the above photo. this time I made it size for size with the knob end. And it did fully seat on.
I think what I observed is how much more rigid and less elastic this particular material is in comparison to the previous cap.
Here are the initial test track plots:
Above: 300 hz (at +12 db) HFN 001
Above: Bass Drum TTR 110
Above: silent groove HFN 001
Listening right after installation:
no need to adjust vta. I'm holding pad thickness within a couple thousandths on each cap. SQ-wise I don't detect anything overtly different. Yet, perhaps on a subliminal level, this one seems more "right". But over the next few days maybe I'll be able to define what it is that I hear that seems more "right" than did the previous cap. Maybe its nothing and I'm just imagining stuff. I'll make an effort to keep my subjective observations grounded to planet earth.
Other notes:
In every silent groove track I've recorded; whether it be standard thrust cap, or either of the two Torlon caps, there is a small spike at 60 hz on each plot. This I take to be coming from the mastering lathe that cut the master to this test record. Because it repeats, I take it we should ignore this artifact and simply take note of the frequencies on either side of 60 hz.
-Steve
Above: 4203 Torlon cap is mounted.
I should note that this cap is the 2nd 4203 cap I made. The 1st 4203 (yellow Torlon) was cut with the ID a few 'tenths smaller. Actually, it was .0006 under nominal shaft size. and it would not fully seat over the knob end of the bearing shaft. So I cut another one. The one in the above photo. this time I made it size for size with the knob end. And it did fully seat on.
I think what I observed is how much more rigid and less elastic this particular material is in comparison to the previous cap.
Here are the initial test track plots:
Above: 300 hz (at +12 db) HFN 001
Above: Bass Drum TTR 110
Above: silent groove HFN 001
Listening right after installation:
no need to adjust vta. I'm holding pad thickness within a couple thousandths on each cap. SQ-wise I don't detect anything overtly different. Yet, perhaps on a subliminal level, this one seems more "right". But over the next few days maybe I'll be able to define what it is that I hear that seems more "right" than did the previous cap. Maybe its nothing and I'm just imagining stuff. I'll make an effort to keep my subjective observations grounded to planet earth.
Other notes:
In every silent groove track I've recorded; whether it be standard thrust cap, or either of the two Torlon caps, there is a small spike at 60 hz on each plot. This I take to be coming from the mastering lathe that cut the master to this test record. Because it repeats, I take it we should ignore this artifact and simply take note of the frequencies on either side of 60 hz.
-Steve
GREAT looking deck there - nice work!
- John
- John
I am impressed with your work Steve!
I follow you tests of the thrust caps you are manufacturing with great interest.
In the meantime I have done som work on my SP-10.
I have added a bottom which is inspired by the Albert Porter design to my old plinth.
The old plinth is a constrained layer Construction consisting of top layer of corian and then several layers of aluminium, mdf and hdf. I have now added two layers of birch and oak Wood, and there is also a brass rod which drains the bearing into a heavy steel block.
[/IMG]
It sounds really nice with an unmodified Rega 250 and Goldring 1042 pickup.
Next step is to get the 12 inch Moerch mounted!
Regards
Nils
Hi Nils.
It's good to have your contribution to this thread. The alternating layers of your plinth do have an attractive appearance. Interesting also about your use of a bearing drain (ala Albert Porter). That one is also on my list of tweaks to implement.
I anticipate your impressions after you have installed the 12 inch Moerch with a suitable cartridge. Fwiw, and imho, no cartridge/phono stage is too good for this motor unit. At least that is the popular hearsay I'm picking up around the web.
Meanwhile, I'm putting hours on the 4203 thrust cap. Sound is as good as I've heard so far. But so was the original and half-way worn nylatron thrust cap.
Next up: Delrin.
-Steve
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.
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.
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I can show the construction of the bottom half of my plinth:
[/IMG]
From underside the steel block is visible. (20 x 10 x 5 cm) It is screwed into the first birch layer with four wood screws (no glue). There is a threaded whole (M8 as I remember), where the brass bolt is screwed into from the top side. That also means that the bolt is further damped by the 4 cm thick birch layer. The head of the bolt touches the bottom of the bearing, thereby draining any vibration from the bearing (thats the theory anyway):
[/IMG]
The top part of the plinth I constructed several years ago inspired by the Cotter plinth as it is described on the soundfountain.com web page. (A PLINTH - TURNTABLE BASE for TECHNICS SP-10 mk2/MkIII Direct Drive -SL-1000 DD Professional Studio Turntable )Top layer is Corian, then several layers of aluminium, mdf and hdf.
The plinth does a very good job, but the finnish is not top.
Next step is to mount the Moerch arm.
I will then look at damping the SP-10 frame and also the bearing housing.
Regards
Nils
From underside the steel block is visible. (20 x 10 x 5 cm) It is screwed into the first birch layer with four wood screws (no glue). There is a threaded whole (M8 as I remember), where the brass bolt is screwed into from the top side. That also means that the bolt is further damped by the 4 cm thick birch layer. The head of the bolt touches the bottom of the bearing, thereby draining any vibration from the bearing (thats the theory anyway):
The top part of the plinth I constructed several years ago inspired by the Cotter plinth as it is described on the soundfountain.com web page. (A PLINTH - TURNTABLE BASE for TECHNICS SP-10 mk2/MkIII Direct Drive -SL-1000 DD Professional Studio Turntable )Top layer is Corian, then several layers of aluminium, mdf and hdf.
The plinth does a very good job, but the finnish is not top.
Next step is to mount the Moerch arm.
I will then look at damping the SP-10 frame and also the bearing housing.
Regards
Nils
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.
I suspect that it might be logical to exploit some of the techniques used in certain isolation platforms. In particular those coming from Symposium Acoustics. Their essential strategy is to conduct spurious vibes and resonances away from the component on top of it down into the platform center where it is claimed to be dissipated. According to their hype they do this by stacking layers of different materials where each has a different material density. Typically, the top layer is the most dense and the center material is the least dense. then this is then mirrored about its center to provide the same layer structure to the bottom side of the platform.
It wouldn't be difficult to duplicate this scheme into a plinth build. And it would not be difficult to use the same or at least similar materials they use. Aluminum or stainless steel at the outer surfaces, then different densities of structural foam for the 2nd and middle layers with the least dense foam at center.
I've spent some time and energy with the application of external damping materials, like Dynamat, to the under sides of Turntable chassis. In particular one TD160C. Doing this I was certainly able to alter the sound of the deck to some small degree. In retrospect I'm not so certain that it was a change for the better. There is the possibility, when using visco-elastic materials to damp a vibrating surface, that the rubbery dampening material stores the vibration energy within it for a while then releases this energy back into the substance that it is contact with. At least that is popular lore. Someone somewhere needs to measure this to prove or disprove it.
Nowadays I'm tempted to just let the chassis vibrate as it does per original design. And, fwiw, there isn't much vibration being generated in a Td160. Even less vibration comes from a healthy sp10 mkII while it is operating.
Another thought; the best way to ensure optimal performance of a turntable is to, at the beginning, ensure that the deck is mechanically and electrically optimal per its original design. Anything less is a band-aid.
It is a good idea to invest in a mechanics stethoscope. With one of these you can hear the vibrations flowing through a TT at various points in its structure wherever you place the probe. With the stethoscope I have to listen very closely to even pick up the vibration emanating from my sp10mkII. With my other decks it is far more obvious.
I'm tempted to try a build where the sp10mkIi chassis stands freely and naked on 5 posts at its faster points. And then have the tonearm board attached similarly. Both tonearm board and SP10 chassis connected this way to a common member. A flat platform. And then use the same test record tracks to plot its performance in comparison to other plinth designs I've used.
Just some random thoughts on plinth design.
-Steve
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