Thanks very much! This is a really useful service you provide to the diy community.
It is also interesting to note that the frequency of the resonance changes with NAD-11 material thickness. And that the thin sample resonates at a lower frequency than the thick.
I can't log onto your site today. Something about the bandwidth being used up. But if I remember, these damping factors are definitely toward the good end, but not the best reporting samples you have tested.
I'd also like to see damping factors for gray iron. The type with lots of graphite flakes in it.
-Steve
thanks Steve, you (and all others) are very welcome.
the lower resonance frequency of the thinner sample over the thicker one has been repeated on other samples where different thicknesses have been tested. It is the same as the calculations, and emphasizes that increasing thickness increases resonance frequency (and lowers the critical frequency) and therefore diminishes the region where mass can help (usually the reason for increasing thickness!)
The web site has been disabled by the powers that be, because it is too popular (go figure!!!). However, I have nearly completed a brand new forum, and I am just putting all the old stuff on it at the moment. That includes all the damping factor data, and I'm adding about 17 plastic materials and a few wood ones, titanium and s/s composite. I'll let people know when it is up.
I saw someone, somewhere advocating the use of Jarrah wood. I've just tested as piece, and it is very good, damping factor 0.396 at 365Hz (not 100x100mm), so the best of natural wood. The bad news is that Jarrah wood has been restricted regarding export from Australia.
I've read about grey iron being better at damping than other irons, but only by comparison! I think the flakes are more likely to be iron carbide, I think graphite would burn off.
the lower resonance frequency of the thinner sample over the thicker one has been repeated on other samples where different thicknesses have been tested. It is the same as the calculations, and emphasizes that increasing thickness increases resonance frequency (and lowers the critical frequency) and therefore diminishes the region where mass can help (usually the reason for increasing thickness!)
The web site has been disabled by the powers that be, because it is too popular (go figure!!!). However, I have nearly completed a brand new forum, and I am just putting all the old stuff on it at the moment. That includes all the damping factor data, and I'm adding about 17 plastic materials and a few wood ones, titanium and s/s composite. I'll let people know when it is up.
I saw someone, somewhere advocating the use of Jarrah wood. I've just tested as piece, and it is very good, damping factor 0.396 at 365Hz (not 100x100mm), so the best of natural wood. The bad news is that Jarrah wood has been restricted regarding export from Australia.
I've read about grey iron being better at damping than other irons, but only by comparison! I think the flakes are more likely to be iron carbide, I think graphite would burn off.
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re: Gray cast iron.
Here's a quote from a foundry website about gray iron:
It is the graphite flakes in gray iron that provide some of its friendly machining properties. That is if you consider the graphite powder that accumulates around the machine tool to be desirable. Actually, it makes a dirty mess wherever the machined chips fall. Imagine pencil lead in powdered form getting all over everything.
Additionally, gray iron is used in situations where some vibration damping is desired. Like engine blocks or gear box cases.
Iron Castings Properties - Foundry Source
The reason gray iron interests me is that it can also be found in austenitic form. Imagine a non magnetic iron with a significant graphite flake composition. All of the desirable properties of iron with the ability to damp vibration. Now what turntable components would benefit from these properties....
-Steve
Here's a quote from a foundry website about gray iron:
It is the graphite flakes in gray iron that provide some of its friendly machining properties. That is if you consider the graphite powder that accumulates around the machine tool to be desirable. Actually, it makes a dirty mess wherever the machined chips fall. Imagine pencil lead in powdered form getting all over everything.
Additionally, gray iron is used in situations where some vibration damping is desired. Like engine blocks or gear box cases.
Iron Castings Properties - Foundry Source
The reason gray iron interests me is that it can also be found in austenitic form. Imagine a non magnetic iron with a significant graphite flake composition. All of the desirable properties of iron with the ability to damp vibration. Now what turntable components would benefit from these properties....
-Steve
Hi Steve,
the values for grey iron I can find, relating to damping factor, is a value of 0.005. This is very small indeed, although much higher than stainless steel, which I saw a figure of 0.0002 for, in the same reference (sorry, I didn't take note of the reference). As I mentioned above, it may have a good damping factor, but only by comparison with other irons/steels, but not judged along side non-metallic materials.
the values for grey iron I can find, relating to damping factor, is a value of 0.005. This is very small indeed, although much higher than stainless steel, which I saw a figure of 0.0002 for, in the same reference (sorry, I didn't take note of the reference). As I mentioned above, it may have a good damping factor, but only by comparison with other irons/steels, but not judged along side non-metallic materials.
Regarding the bearing drain... If you use an aluminum layer in the plinth, would it not be sufficient thread a rod/bolt through this layer and simply touch the bearing housing with it?
The vibrations from the bearing would travel through the bearing houwing, through the bolt, and into the aluminum layer where they get damped by the sandwich of plinth materials.
The vibrations from the bearing would travel through the bearing houwing, through the bolt, and into the aluminum layer where they get damped by the sandwich of plinth materials.
the project still lives
This has been dragging along for years.....literally. However, work is in progress at the graphic work station (aka PC) and has been moving along. At this point everything is still conceptual, but I have settled on a plan of action.
I intend to have the "test mule" plinth operational by Friday next, if not sooner. Emphasis will be on functionality over aesthetics. And, if the "test mule" is successful, I may listen to a few records on it as I establish this new base-line.
coming soon!
-Steve
This has been dragging along for years.....literally. However, work is in progress at the graphic work station (aka PC) and has been moving along. At this point everything is still conceptual, but I have settled on a plan of action.
- agenda
1: make a minimalist test mule type of plinth for taking measurements
2: develop a method for recording and documenting performance data such as rumble and wow/flutter
3: establish this as a base-line for future plinth developments
4: establish this as a base-line for refurbishment of the sp10 mkII internals and power supply.
I intend to have the "test mule" plinth operational by Friday next, if not sooner. Emphasis will be on functionality over aesthetics. And, if the "test mule" is successful, I may listen to a few records on it as I establish this new base-line.
coming soon!
-Steve
rumble test:
Use a record with large "blank" * spaces. Play the "blank" with my SP10 while recording to a ML-9600 hard drive recorder. Burn a CD of the "blank" recording. Put the CD on my PC and use Audacity to analyze the "blank" signal for DB.
*"blank" = no grooves
For wow/flutter I have a test record or two which offer tracks designed to test wow/flutter. Same procedure with this. Play record tracks while recording to ML-9600. Put resulting CD on PC and use Audacity again.
I'll post results here. Hopefully, if any of those who have actual experience in the field (so to speak) with w/F and rumble measurement see this thread, they are very welcome to chime in and critique my process.
-Steve
PS: next step. I am nearing completion of a concept for my "test mule" plinth. I'll post sketches of it by late today, or tomorrow. The project is in motion, finally.
The test mule
The test mule structure is to be light and reasonably rigid. The build will be in a stacked layer baltic birch multi-ply configuration.
My reasoning for the light structure is to allow the motor unit to produce whatever mechanical noise that it does without having to wonder if the plinth is damping/masking this noise. This way I can better analyze the condition of the deck.
I expect this build to produce a higher level of rigidity than it may initially appear.
I have 4 Stillpoints cone feet to support the structure. The Stillpoints are internally threaded for 1/4-20 unc threads. A very popular size in the audio world. This design will allow a small range of vertical adjustment to help level and stabilize the deck. Especially on a 4 point support where the structure is rigid, some adjustment will no doubt be required. But if I build this plinth like I should there won't be much need.
I can further tune the noise dampening ability of this deck by means of choosing different support surfaces for the plinth to stand upon. Initially, I will choose a support structure that does not provide significant damping ability. Then, later, I may slip one that does underneath and measure again.
Wait. What about the measurement method:
As noted in a post just prior, I intend to use a "blank" record to record for rumble. I will take the cables from my phono stage and plug those into a Alesis Masterlink 9600 and record the rumble session. Then burn a cd with the "blank" track on it. Then take Cd to my PC and use the software on that machine to record for decibel levels and frequency.
Same procedure will be used for wow/flutter except that I have a couple of test records that have wow/flutter tracks on them.
For rumble, any record with a significant blank space can be used. Basically, we do not want to be tracking any groove cut by the mastering lathe. Rather, the flat space with no grooves is desired.
For wow/flutter I have one record that does have tracks for testing this. That record is "Allied Radio Stereo Setup Test and Demo Records No, 1,2,3. Cat#CSDT. It is record 1 in this box set that contains the wow track and the flutter track. I'll make recordings of those and then make those recordings available on my website for anyone to download and analyze on their own PC. Same for the Rumble tracks.
The idea is to collect this data as an initial point of reference. Then, after having performed refurbishment to the electronics and/or bearing another test can be made for comparison. further, if in this first test I find significant wow/flutter levels outside the norm for this player, I most certainly know that the deck requires repairs. Likely to the electronics side. However if I record very good levels on this test, I may wonder what, if any replacements to the electrical side may be necessary.
I'll know more later this week after I get this "test mule" built.
-Steve
The test mule structure is to be light and reasonably rigid. The build will be in a stacked layer baltic birch multi-ply configuration.
My reasoning for the light structure is to allow the motor unit to produce whatever mechanical noise that it does without having to wonder if the plinth is damping/masking this noise. This way I can better analyze the condition of the deck.
I expect this build to produce a higher level of rigidity than it may initially appear.
I have 4 Stillpoints cone feet to support the structure. The Stillpoints are internally threaded for 1/4-20 unc threads. A very popular size in the audio world. This design will allow a small range of vertical adjustment to help level and stabilize the deck. Especially on a 4 point support where the structure is rigid, some adjustment will no doubt be required. But if I build this plinth like I should there won't be much need.
I can further tune the noise dampening ability of this deck by means of choosing different support surfaces for the plinth to stand upon. Initially, I will choose a support structure that does not provide significant damping ability. Then, later, I may slip one that does underneath and measure again.
Wait. What about the measurement method:
As noted in a post just prior, I intend to use a "blank" record to record for rumble. I will take the cables from my phono stage and plug those into a Alesis Masterlink 9600 and record the rumble session. Then burn a cd with the "blank" track on it. Then take Cd to my PC and use the software on that machine to record for decibel levels and frequency.
Same procedure will be used for wow/flutter except that I have a couple of test records that have wow/flutter tracks on them.
For rumble, any record with a significant blank space can be used. Basically, we do not want to be tracking any groove cut by the mastering lathe. Rather, the flat space with no grooves is desired.
For wow/flutter I have one record that does have tracks for testing this. That record is "Allied Radio Stereo Setup Test and Demo Records No, 1,2,3. Cat#CSDT. It is record 1 in this box set that contains the wow track and the flutter track. I'll make recordings of those and then make those recordings available on my website for anyone to download and analyze on their own PC. Same for the Rumble tracks.
The idea is to collect this data as an initial point of reference. Then, after having performed refurbishment to the electronics and/or bearing another test can be made for comparison. further, if in this first test I find significant wow/flutter levels outside the norm for this player, I most certainly know that the deck requires repairs. Likely to the electronics side. However if I record very good levels on this test, I may wonder what, if any replacements to the electrical side may be necessary.
I'll know more later this week after I get this "test mule" built.
-Steve
Hi Steve
Before you do any tests you could make sure your SP-10 is working properly ? Examine the waveform on the motor coils, if it is very rough with loads of HF stuff, replace the three capacitors in parallel with each of the three motor windings. In my experience all other capacitors are just fine.
Then check the PLL set-up, this does drift with time.
Then you can confidently start testing knowing it is mostly at Technics made it ? Assuming you cleaned out the bearing and put in fresh oil.
Finally Stillpoints are very hard indeed, you may like to use nothing at all, or sorbothane ? On rumble measurement you might even be able to measure passing traffic, I can with a solid concrete floor !
Sorry if this has been repeated before.
Regards
Dave
Before you do any tests you could make sure your SP-10 is working properly ? Examine the waveform on the motor coils, if it is very rough with loads of HF stuff, replace the three capacitors in parallel with each of the three motor windings. In my experience all other capacitors are just fine.
Then check the PLL set-up, this does drift with time.
Then you can confidently start testing knowing it is mostly at Technics made it ? Assuming you cleaned out the bearing and put in fresh oil.
Finally Stillpoints are very hard indeed, you may like to use nothing at all, or sorbothane ? On rumble measurement you might even be able to measure passing traffic, I can with a solid concrete floor !
Sorry if this has been repeated before.
Regards
Dave
Hi Dave. thanks for that input.
At this point I have no means to produce a motor waveform. (no o-scope)
At present, the unit has been reassembled, bearing cleaned, and with fresh 20 wt lube. The motor unit and PS stands upon a table top. The unit appears to turn on/off with no drama. The platter spins and stops on a dime under its own power. And when the PS is switched off the platter spins freely when nudged by finger. Seems correct to me.
fwiw, history of the unit with me is it was purchased by me a couple of years ago. First thing I did was put the sp10 in a medium mass birch ply plinth, mounted a Zeta tonearm with DL103R(wood bodied, SS retipped) and spun vinyl for about 4 months. It sounded beautiful to me at that time. Now, the only difference is that the bearing has been cleaned and that older plinth is gone and I will build a new one.
re: speed drift. Strobe appears rock steady as I observe its operation presently. No means to check speed other than by visual as it stands powered up and by itself on the table top.
At the beginning and mid points of this thread I have some photos of the unit as I received it and also as I took the thing apart. I think photos suggest that the motor unit side had not been dismantled prior to my tinkering. I replaced none of the electronics bits. And I have not taken the cover off the PS. But that side of it, the PO may have done some work in there. As noted, the unit appears to function normally.
re: footers. Yeah, these Stillpoints will be "hard" footers. Alternately I can substitute very large heavy tapered rubber feet that are nearly as large as the Stillpoints. Fwiw, all testing will be done with the motor unit in plinth aboard a Minus-K isolation platform.
In my experience, the turntable obtains enhanced performance,complete with a very quiet background, while standing on this unit. But I have only used the Minus-K with the Thorens pictured. It will be in use for the SP10 as I put it through its paces.
I get your point about "passing traffic". I think the Minus-K should isolate for these tests nicely, but we will know more when I have some frequency and amplitude charts to look at. That will come next weekend after I've got the test mule plinth built and the sp10 mounted to it complete with tonearm. I'll be using a Graham 2.2 with Shelter 501-II in this iteration.
-Steve
-Steve
Solid slate both levels and the riser blocks are from the same quarry. I've got a bit of blu-tak in there somewhere. I may use the lower large slab of slate currently under the TD124 as a surface for the SP10, in its test mule plinth, to stand on. Although with the Minus-K I need to arrive at a minimum (90lbs) / maximum (150lbs) weight window for the Minus-K to become operational.
.
Wow ! love the Minus-K isolation platform, how much was that !
The PLL set point will drift over the years, but the actual speed will stay constant. It just means the electronics are trying harder, and that might affect the performance ?
The Graham and 501 would be great. I use a SME V and depending a Benz LP-S or AT33EV. Cheap arms are a waste on what could be the best turntable in the world ?
Regards
Dave
Wow ! love the Minus-K isolation platform, how much was that !
The PLL set point will drift over the years, but the actual speed will stay constant. It just means the electronics are trying harder, and that might affect the performance ?
The Graham and 501 would be great. I use a SME V and depending a Benz LP-S or AT33EV. Cheap arms are a waste on what could be the best turntable in the world ?
Regards
Dave
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More about how I came to meet this Minus-K here:
Minus_K
Out of the blue. It is a review sample. Hopefully, a long term review. I love this thing!
Agreed re: tonearms/carts on the sp10. It sounded good using a Zeta with wood bodied/ruby cantilever/FL diamond Dl-103R. I'd expect more out of the Graham/Shelter. My experience so far with the Graham on a few different turntables is that it does allow us to hear pretty deep into the groove. And it handles stiffly sprung MC carts very well. Very refined. It seems to tame what could be edginess with the Shelter were it mounted on a lesser arm. (been there)
re: electronics side. This will be a learning experience for me and I very much appreciate your input.
-Steve
Re arm choice, although the Graham which I had (10 years ago) was OK with medium to high compliance cartridges, it was very poor with SPU and Kondo Audionote Io, although both work well with a DIY very heavy unipivot and also with FR64S. Zeta is also pretty good. Seems that the Graham is too light and the energy produced by low compliance cartridges causes loss of contact at the bearing.
I mention this only as I seem to remember seeing that you use low compliance MCs. With the right cartridge the Graham is of course excellent.
I mention this only as I seem to remember seeing that you use low compliance MCs. With the right cartridge the Graham is of course excellent.
user510, you suck! not really
A great looking project. I am sure it will sound great. And it should be useful as a TOOL, as you suggested it is to become. Somewhat skeletal such as those plinths built by Terry Cain.
As the original poster of the Chadwick mods to your site (via aa) years ago, (and my continuing developments from my own experiences) may I suggest something that will kill fewer trees? If making from BB, please glue strips up to make the perimeter frames, as this will minimize waste (you probably have lots of scraps and off-cuts). Else I might suggest the use of hickory. It is very hard, quite dense and is very stable dimensionally if finished (and can be free if you can re-cycle old hockey sticks if anyone is still using the wooden ones).
A great looking project. I am sure it will sound great. And it should be useful as a TOOL, as you suggested it is to become. Somewhat skeletal such as those plinths built by Terry Cain.
As the original poster of the Chadwick mods to your site (via aa) years ago, (and my continuing developments from my own experiences) may I suggest something that will kill fewer trees? If making from BB, please glue strips up to make the perimeter frames, as this will minimize waste (you probably have lots of scraps and off-cuts). Else I might suggest the use of hickory. It is very hard, quite dense and is very stable dimensionally if finished (and can be free if you can re-cycle old hockey sticks if anyone is still using the wooden ones).
Hi again Dave.
Can the caps you mention be seen the the schematic below:
or this one
I can also provide photos of the 4 populated pcb's.
another Q:
by looking at a close-up detail of the caps in question, (once I've identified the cans) can you tell by the external graphics on them if they are original or have been replaced at a later time?
I have a capacitance meter, and a digital multi-meter that can be used to check some of the values.
-Steve
I've used this Graham off and on with the Shelter 501-II for several years now.
While it is true that the Graham 2.2 is stated to be an arm of approximately 12g effective mass, it is also very easy to tune to a higher mass condition. What with the add-on cw weight that is attached via two bolts to the rear. Above photo shows my 2.2 with a head weight mounted and the Shelter. This particular Shelter has a compliance of around 9 (x 10^6 cm/dyne) and is visibly quite stiff. With the head weight and auxiliary cw mounted and vtf adjusted this arm/cart combo is measured using the HFN001 test record for lateral resonant frequency and resonates at 9 - 10hz. Very similar to where I mass tune for my Dl103R cartridges.
Listening indicates that it seems like a very happy match-up to my ear.
-Steve
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