@holmz , The new Sota bearing is just like the Clearadio. It has a magnetic thrust mechanism. The female section of the bearing is an integral part of the platter so what you are talking about is a new platter assembly which is heavier than what you currently have and the suspension will sag and it’s resonance frequency drop.
The old platter goes on the existing table.
I was thinking I could recycle the old arm, motor and cart into a table for my daughter, or to use in the shed outside.
To do that I would need a plinth, bearing and platter. I have access to a lathe and would likely use acrylic and maybe stuff in some copper plugs towards the outer edge to make the intertia a bit higher without making it heavier.
And since that would be a second table it would not have the Sota springs, but maybe some anti vibration feet to hold the plinth up.
You are best off sending the table back to Sota and let them upgrade it for you or just trade it in on a new Sapphire Eclipse. You might as well add vacuum clamping while you are at it.
SOTA have been good, and I have rebuild stuff for the existing table from them.
I was more than just a little bit reticent in sending back the whole table, but I did send back the platter Friday.
In hindsight, I could have sent the platter assembly, separate from the table, and kept the cover here.
And then reassembled it back here.
As far as multiple arms are concerned if you get additional; tonearm boards weighted for any specific arm you can have several arms mounted up and fully aligned then changing arms is a snap. Three Allen cap screws is all you have to undo. I can change arms in less than five minutes. I am contemplating getting a wood CB directly from Frank Schroder and doing just that.
I made my first arm board about 1988 I think.
And two more a month or three ago.
The CB-9 is going on one of those two arm boards. Basically I had enough alloy for two, and if I jacked up the drilling I would have a spare.
I would be a bit apprehensive changing an arm board with the CB-9 and cart attached. It would be easier/safer if it had a removable head shell.
The drilling went easier than I expected and the spindle to hole was bang on 222mm. It took a bit of futzing around with a calculator, calipers, center drills etc.
Since I did not have a 10” caliper, I took a scrap of alloy and measured from its edge.
I am dropping off the alloy arm board to get a black anodise.
The Pythagorean math was left on the alloy disc.
With the CB-9 fully lowered, it is pretty flat and makes it easier to measure. But when doing the arm board scribing, there is a drop between the table and the arm board. Nothing too difficult, just time consuming to check, recheck, check 4 more times.
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Mijostyn , I am well aware of the difference in the method for speed control between the SOTA eclipse system, and the Denon Dp80, because I have both, as you may know. Of course, I do not own a Sota TT, but I have the phoenix engineering prequel to it, controlling the speed of my Lenco. Now as to which is the better way to control speed, you are just making up a story that fits an argument that the Sota method (or the phoenix engineering method) is superior to that of the Denon. I could make up an equally compelling argument in favor of the Denon, but since we have no head to head data, I won’t bother. The Denon is extremely good at it, and so is the eclipse system, and I defy you to hear a particle of difference between them . Denon did publish specifications, showing speed stability over time when they marketed the Dp80. If you search for their promotional material from that era, you will find it. Data are shown in their owners manual, I think. I might also add that the Kenwood L07D from 30 years ago used a magnetic elevated bearing. You could also say that the Verdier TT which is entirely based on magnetic elevation, in the vertical plane, is now vintage material. Several other makers use full or partially magnetic vertical bearings too. So the SOTA mag lev bearing is not earth shattering or groundbreaking, but I am sure it is an improvement over the previous bearing.
As to springs, what I object to is internally, sprung turntables, where the motor on one hand and the platter and bearing on the other are treated differently, which is to say the motor is usually unsprung whereas the platter and bearing are sprung. I have reiterated this argument and my feeling about it many times over. That arrangement makes it impossible to avoid some speed variation Whenever the suspension is activated, because activation of the spring suspension will inevitably stretch or contract the belt which will change the speed momentarily. I could hear this effect quite plainly with my SOTA star sapphire vacuum hold down turntable that I owned for 10 years. This has little to do with the Minus K.
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It has also proved useful that the DP-80 Platter is a Two-Piece Assembly, as the Lower Section interfaces with the Speed Control System and the Top Section is able to be produced from different materials.
I have a substantial Phosphor Bronze Top Section. The design enables it to be used as a Platter on other TT's.
I also have purchased a few Spare SP10 MkII and DP-80 Platters for the future and for some usage on a few trial ideas I have come across and had brought to the table for discussion with an engineer, who will qualify as a TT specialist, if a title were to be given.
The TTS 8000 has a similar magnet speed control via a Magnet Strip but is a much harder to discover platter for sale, a few years of searching has not shown a platter on offer only from the usual search sites. The engineer I use has this TT and has had to consider using the only Patter available for this model to produce the modifications that have been under discussion.
It is a difficult call to work out how far Mod's should be introduced to Vintage TT's especially when a selection of models is at hand.
The Aurex SR 510 is the one that is begging to be given a full attention.
The Aurex has a different Speed Control, being that it is a concealed under platter incremental marked disc that is read to control speed, which is observed through a Periscope Type Lens for the stability.
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@holmz , The new Sota bearing is just like the Clearadio. It has a magnetic thrust mechanism. The female section of the bearing is an integral part of the platter so what you are talking about is a new platter assembly which is heavier than what you currently have and the suspension will sag and it's resonance frequency drop.
You are best off sending the table back to Sota and let them upgrade it for you or just trade it in on a new Sapphire Eclipse. You might as well add vacuum clamping while you are at it. As far as multiple arms are concerned if you get additional; tonearm boards weighted for any specific arm you can have several arms mounted up and fully aligned then changing arms is a snap. Three Allen cap screws is all you have to undo. I can change arms in less than five minutes. I am contemplating getting a wood CB directly from Frank Schroder and doing just that.
@lewm , it is interesting that the DP80 and Sota both read a trigger under the platter to gauge speed. In the Sota's case it is a small magnet. The controller's response is different. The Denon makes an immediate adjustment while the Sota makes its speed changes very slowly. The MinusK is full of springs by the way.
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To give a better opportunity to acquire a Plinth Material of interest.
Search for Densified Wood Suppliers. The general rule is a Board Produced with Cross Grain Ply, 25 Layer per 25mm and boded with Phenolic Resin is the Goal.
Permali will potentially be your first discovery. This material is similar in Density @ 1400Kg per m3. It has a Damping Factor that is in keeping with P'holz, but I think it has a variance in the frequency, so dissipates energy with a difference, maybe that is down to Beech and Birch wood as the base materials.
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Holmz, just buy the SOTA Eclipse package complete. Does it occur to you that the question “ where do I buy a DIY platter and bearing?” Is internally an oxymoron, since DIY implies you want to make those items yourself.
I got the motor package and all the stuff.
Now will be getting the bearing for the existing table.
This bearing I am looking for, is for the left over bits… arm, cart, old motor…
If I could get a Clear Audio magnet bearing assembly, that would be ideal and I could make a plinth and have a second deck.
…Well it would be a plinth and then a platter to go onto the spindle/bearing assembly.
Add P'holz to add to the management of energy transfer, well I wish I present to see your expression at the first Album Reply with the new designs in use.
No Panzerholz that I could find available in Australia, and the places in the US sell it by the 4’x8’ sheet.
I’ll try a router forum, and see if some others have off cuts or want to get parts of sheets.
Basically I need one piece, or a couple of pieces, that are closer to the size.
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Holmz, just buy the SOTA Eclipse package complete. Does it occur to you that the question “ where do I buy a DIY platter and bearing?” Is internally an oxymoron, since DIY implies you want to make those items yourself.
Raul, I have no conviction about what is the best suspension. I think each turntable and each environment may require a unique solution. But I do admire the Minus K, and I do dislike internal springs.
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@holmz I am not familiar with the SOTA Bearing but in general the designs are to have a few sacrificial parts incorporated in the Housing.
The Housing Liner Bushes are Sacrificial, and the Ball at the Base or Sometimes Head of the Spindle are Sacrificial.
A Ball can also be found to be an Interference Fit which is embedded into the spindle and will be seen as a Half Ball when witnessed.
Bush Liners are able to be produced from a material of choice to the tightest of tolerance to match the spindle that is in hand, this is very beneficial.
There are numerous considerations for the material that can be selected for the replacement of a ball, I lean toward the lowest 'coefficient of friction' at this interface, but this can result in using a fragile material.
It is working with these components in the Bearings Assembly that usually produces an overhaul.
The Spindle is commonly found to be produced with a Case Hardening and will have to be subjected to substantial period of use in an unwanted environment to show abrasive damage or at the worst a measurable wear.
The Sump of the Bearing Housing can be prone to leach lubricant, measures are usually adopted to improve on the seal at this point, as having options on Lubricant Type can be beneficial.
Options on Viscosity of Lubricant from High to Low Viscosities are not a bad place to be. It is not uncommon to see where individuals have reported on the merits of a particular viscosity being in use.
If the Bearing assembly was optimised the impact on the replay is substantial, the Styli in the Groove will be in its best environment with an optimised spindle rotation and low mechanical energy transfer resulting.
Add P'holz to add to the management of energy transfer, well I wish I present to see your expression at the first Album Reply with the new designs in use.
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@pindac @vinylzone et. al.,
I got the arm board drilled, and the sub chassis springs in.
Will work on the motor and controller, and wiring next.
I found that the bearing is shot in the SOTA.
But it make not obvious noise, so I’ll get the arm set up while emailing back-n-forth with SOTA.
Where does one get a DIY platter and bearing?
I am thinking I have the old motor and its power supply and the old arm.
I could just chuck it all onto a plinth of some sort (maybe a panderholz board) and then if I. had a platter/bearing assembly, I could have a second TT for use in the shed?
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Look forward to your update, following the addition of the kit.
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I decided ti just order a hot rod kit to bring the old SOTA up to spec.
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@holmz The link might bring a few hours of interest with a cup of coffee in hand.
Best Coffee and not whiskey, as the latter does have a habit of making big decisions very easy, on a more than wanted frequency.
PM me if you would like a further description about the link.
https://www.fromjapan.co.jp/en/
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Have you ever given LENCO TTs a thought?
…
Yeah - there was a fellow in SF that has an older one in 240v, but that went a bit cold. I might reach out again, as if I just do the Eclipse/roadrunner on the Sota I could run it while the Sota is belly up.
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Have you ever given LENCO TTs a thought? When rebuilt and mounted on new plinths, these offer superb performances....I know because I have two such TTs. One is from an old Lenco L70; the other from a L75. Both are fitted with quality Jelco tonearms and they simply sound wonderful.
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There was a host of posts appear about the perception of improved SQ within systems be noticed.
The period was known as the unprecedented period for using modern HiFi, as the Grid Power Supply was not being drawn on in a capacity that is usual, and the reduction in Traffic and Transport Services had substantially reduced seismic activity, the seismic monitoring stations was reading this drop in vibration.
Again a group of individuals across the world detecting change through subjective, evaluation, with a little bit of additional ambient environment being known of to make the claims seem feasible.
It is possible that people with nothing to do were more attentive to the music, in general, because they had less on their minds… or just to escape the drama. And perhaps they believed that it sounded between because they listened better?
The most commonly used vibration measurement methods, which are using accelerometers and laser devices as the methods to measure are not suitable for vibration measurement of micro vibrations. The methods referred to as Optical interferometry has the advantages of being a non-contact system and measures to a very high accuracy.
If someone (like @vinylzone ) had another system available…
Then they could:
- Power the speakers with system #2, running it hotter than normal.
- Put the stylus on a non spinning table
- Listen, or record, what is coming through the TT system… as any vibs will be shaking the interface between the cart and turntable.
I would expect that low freqs would bleed through, with their higher amplitude… but who knows?
If something was coming through, then repeat the test with System #2 playing pink noise and we could then figure out the freqs that the systems is most prone to resonating at, and what the apparent Q is.
There might be other ways, but this seems pretty quick if one can disconnect the phono stage and has a ADC to record with.
It is possible that the musical signals could be coupled into the phono units electrically… but keeping the phono stuff away from the other cables should help.
it is somewhat better than the laser gear, as if the plinth was stable and the arm was being shaken we still get a measurement… and visa versa.
And if they are both in a common mode, then any “CMRR like” effect would result in low apparent vibration.
And they could do the pink noise testing at 70, 80, 90, 100 dB… to further understand it.
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The following are a few statements made within a few previous posts, and then low and behold a subjective assessment is all that is required to produce reassuring evidence.
Ones ears are great tools, if the perception of SQ is a detractor, then a stimulation can be created to pursue a furthering of used methods to find a presentation that is an attractor, that can be achieved by a rethink on the methods used for mounting from the Rack Shelve up to the Platter Mat in use.
Out of interest during the Covid lockdown period throuout the globe.
There was a host of posts appear about the perception of improved SQ within systems be noticed.
The period was known as the unprecedented period for using modern HiFi, as the Grid Power Supply was not being drawn on in a capacity that is usual, and the reduction in Traffic and Transport Services had substantially reduced seismic activity, the seismic monitoring stations was reading this drop in vibration.
Again a group of individuals across the world detecting change through subjective, evaluation, with a little bit of additional ambient environment being known of to make the claims seem feasible.
I do not recall any of the contributors to a thread needing to supply data from recorded measurements of their own systems to prove their reports being substantiated, the ears were looking good enough, and the trend for the reporting maybe produced an increased awareness to the attractive perception that was present.
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Seems that your statement is mainly subjective and I think that you need to measure as @mijostyn posted, I' agree with him .
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Dear @vinylzone : " I do not have any vibration or rumble issues in my setup, "
How do you know, how can you be so sure?
I ask because time ago I was sure that my analog rig was free of any kind of generated distortions related as what we are discussing here with you.
A few months ago my friend Carlos came to my place and we were listening MUSIC, mainly classic because he is a Simphonic Orchestra player. Obviously that he is accustomed to listen at high SPL as in a live even seated at near field. So in one LP ( non classic score but Asian drums. ) with SPL over 95db and with a low bass reproduction part the windows started to vibrate... after that I told you Carlos if that vibrations affected the other frequency ranges ( mid/high ) sk if he detected " something " and like me he told me that does not detected any kind of " problem " about.
I took that experience as a confirmation that my analog rig was safe of that kind of " events "
_________________________________________________________________
The most commonly used vibration measurement methods, which are using accelerometers and laser devices as the methods to measure are not suitable for vibration measurement of micro vibrations. The methods referred to as Optical interferometry has the advantages of being a non-contact system and measures to a very high accuracy.
______________________________________________________________
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@mijostyn
Battle? I thought it was a discussion, an exchange of ideas and experiences.
I have the Sota Total Eclipse package on my tnt, and it is a fine drive system. I may consider it for the DIY table.
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Everything in the eBay address from the question mark on (including the ?) is irrelevant and is best removed as it's only purpose is tracking.
https://www.ebay.es/itm/194880213872 is completely adequate and preferable.
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I also get a bunch of kudos for my finger joints. Life is good:-)
Literally woodworking finger joints?
or figurative finger joints like give someone the bird? 😂
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@vinylzone , I really do not want to be a Pita. I think you did a great job building your own table. My intension was to suggest improvements no get into a battle.
Any vibration coming from the cartridge should be dissipated in the tonearm. Nothing should be getting to the plinth. Unfortunately, you have a unipivot arm which is much poorer at dissipating energy than an arm with fixed bearings. You have loads of noise getting to your cartridge. You could place the table on a MinusK stand but that is expensive. You can isolate the table on your own for much less money, a fun thing to do.
As for my turntable yes, I had a problem with feedback because of a resonance issue given the prodigious bass my system can produce and the location of the turntable. That resonance has been entirely mitigated with a simple modification. The turntable is now dead silent under any circumstance and nothing phases it including jumping up and down in front of it and charging into the cabinet it rests on. Given it's suspension, magnetic thrust bearing and isolated dust cover it is as quiet as a turntable can get. Speed deviation is no more than +- 2 thousandths of a revolution. At this very moment it is +- 1 thousandth going slowly back and forth between 33.334 and 33.335. As it is also a vacuum table most of the surface irregularities have been sucked out leaving only spindle hole eccentricity as a pitch modifier. With a concentric record pitch is delightfully stable. As good or better than any turntable made. Not bad for 15K. I also get a bunch of kudos for my finger joints. Life is good:-)
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Would the average enthusiast for using LP's to replay a recording, find it necessary to use such an experience to suggest that a few subjective evaluations, where a friend or two likes the experience and musical encounter with their preferred music being replayed, is an evidence that you are an authority and guru on a set up for a LP replay.
I am not sure he is claiming guru authority?
I thought it was more like a description or observation.
I would probably have stayed with the plywood if I thought it was vibrating, just because I “believe” it damps better.
But the maple should be stiffer, and in a system mounted on a solid wall, it makes sense too.
Anyhow… I appreciate @vinylzone input and yours.
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@vinylzone To not detract too far from your entrance into this thread, I believe your TT with the new adornment of the Maple Sub Plinth has improved on the role over the Plywood it has replaced.
I know this wood is selected for use in musical instruments for its damping properties, and more importantly how it impacts on the overall structure of the musical instrument when present and carefully attached, I would class this as a complex structure.
My structures produced are not complex and I have even produced a structure that can have a Sub Plinth in suspension on O Rings, a little like a SME Suspension Method.
I chose not to follow up on this method as it was precarious and not really trusted with valuable equipment sat upon it.
The Solid Tech 'Feet of Silence' have offered a variant of this type of a suspension support, and have been very satisfactory and remained as the most valued footer.
Their offered improvement over all other used footers, at being able to deliver a noticeable removal of smearing and offering increased perceptions of attack, dynamics, envelope and micro dynamics is quite something.
Your structure and your use of Maple is not as complex as a musical instrument structure, but I feel it can impact on the SQ in a manner that makes it a worthwhile choice.
Subjective evaluation from, in use/not in use periods, might give the additional reassurance for the choice made, but I would assume you have already experienced a this when the Plywood was swapped for the Maple.
Having a few friends over is good thing, I would not deny anybody that experience, if it good for the mind, its definitely good for the body and spirit.
Would the average enthusiast for using LP's to replay a recording, find it necessary to use such an experience to suggest that a few subjective evaluations, where a friend or two likes the experience and musical encounter with their preferred music being replayed, is an evidence that you are an authority and guru on a set up for a LP replay.
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Dear @vinylzone : " I do not have any vibration or rumble issues in my setup, "
How do you know, how can you be so sure?
I ask because time ago I was sure that my analog rig was free of any kind of generated distortions related as what we are discussing here with you.
A few months ago my friend Carlos came to my place and we were listening MUSIC, mainly classic because he is a Simphonic Orchestra player. Obviously that he is accustomed to listen at high SPL as in a live even seated at near field. So in one LP ( non classic score but Asian drums. ) with SPL over 95db and with a low bass reproduction part the windows started to vibrate... after that I told you Carlos if that vibrations affected the other frequency ranges ( mid/high ) sk if he detected " something " and like me he told me that does not detected any kind of " problem " about.
I took that experience as a confirmation that my analog rig was safe of that kind of " events " but I took a road to eliminate those window vibrations and in that road I find out that even that my friend and I can't detected any proble at high SPL with a high resolution full frequency response ( at least 16hz to 50kh) system in reality was not totally safe.
Total isolation of the TT/toneam/cartridge is not an easy target even if the analog rig is in other room. It's common sense and can bre preoved using sciene/measures and you are tell us that have a total/perfect isolation.
Something very good or bad in your system that I don't know its items, I think you have the small Maggies, Herron or something similar and what we look in that picture of your analog rig.
I have no questions for me, I know the answers. You need to make to question your self about.
R.
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@mijostyn
In the video, the turntable is on a floor stand. Mine is not. I do not have any vibration or rumble issues in my setup, Springs isolate in both directions, and while they may help in some situations, can also prevent passing higher frequency vibration from the platter/plinth back down to any platform or subchassis that a turntable might have.
If I recall correctly, which I may not have, you experience this as feedback some time ago and had to take other measures to mitigate it.
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@vinylzone , I hate to tell you this old man but that is a fallacy. Just like air sound travels through the ground in waves. As a truck rolls down your street your cartridge can hear that right through the concrete. Your cartridge can also hear a lot of other stuff like your washer machine being unbalance and your refrigerator compressor starting up. It can also hear your HiFi System. Does not matter what you have the turntable on certain frequencies will make it to the cartridge by direct mechanical means or through the air. All this is distortion.
Towards the end of this demonstration there is an example of house rumble. Watch it!
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A recent new Member to my local HiFi group, has been quite impressed with the Isoacoustics Oria Footers that they have been loaned to try out in their system.
Following the experience with the Panzerholz and the AT 616 Footers the same person has sent out a link to the HiFi Group of a device they are considering buying for there TT.
It looks like it is a substantial piece of kit and hopefully if acquired it will prove quite valuable to their set up, it can be seen in the attached link.
I have set speakers up in the past on Heavy Plinths with AT 616 feet under the speakers and got very pleasant results.
I have set up similar methods for others, using their speakers and the result has been either Isoacoustic Gaia Footers are now in use or a Townsend Sub Base.
The Footer I use directly in contact with my TT Plinth is the Solid Tech 'Feet of Silence'. I have yet to have this footer improved on.
My assessments are subjective like 1000's of assessments, I don't measure such things, as I don't know how to do so accurately.
The most commonly used vibration measurement methods, which are using accelerometers and laser devices as the methods to measure are not suitable for vibration measurement of micro vibrations. The methods referred to as Optical interferometry has the advantages of being a non-contact system and measures to a very high accuracy.
Devices to measure ambient vibration accurately and that can supply a trusted reading of a condition that can have a detrimental impact on a stylus when positioned in the LP groove are not very affordable, and are certainly not on any HiFi enthusiasts that I know equipment list.
I do believe there is a lot more available to impact on a stylus in a detrimental manner manifesting from within a Bearing Assembly, Bearing Housing Mounting Method or from the Tonearm having design flaws where bearings are as friction free as can be or internal wiring is restrictive to free wand movement.
If the TT and Tonearm have both cncerning conditions in conjunction I don't think knowing about ambient micro vibrations and putting in control measures is going to have too much a impact on the overall situation.
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@lewm , you always has a " but " and it's ok with me but then please your perfect solution about, we need your contribution for all we can learn.
R.
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What Raul says is undeniably correct, but I don't think a spring suspension is a panacea that puts an absolute end to "vibrations and resonances at microscopic levels". In fact, in some cases, or if badly implemented, such a suspension can make matters worse.
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Dear @vinylzone : " I don't need that kind of isolation. No structure borne vibrations make it to the plinth. The sub floor is a cement slab. "
Vibrations or resonances at microscopic levels has a direct influence in what the cartridge stylus can pick up due theat the cartridges are en extreme sensitive to any kind of " movement ".
Seems that your statement is mainly subjective and I think that you need to measure as @mijostyn posted, I' agree with him .
Several times with original stock TT/onearm designs we just can't be aware of those microscopic " distortions " because due to the resolution levels of the room/system we can't be aware of that or maybe because we don't yet know what to looking for but what you can be sure is that those " distortions " exist and modulates the kind of colorations you are listening in your system.
Of course you are satisfied with what you have and looking that you like the DYS kind of work making measurements of what you did could be interesting for you or maybe you just don't care about.
R.
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I recently purchased a Board of Densified Wood, the Panzerholz Brand, solely to be used for TT Plinths.
A change to how I am living is creating the need for me to put the HiFi system into storage for a period of time.
With the change of plans, I have made use of the P'holz as a Sub Plinth Material with AT 616 Footers, and used it on a Valve CDP Design and a Garrard 401 TT, in two different environments.
When the devices were mounted on the footers AT 616 only at the latter part of the listening session, the benefit of the P'holz was immediately recognised for its positive influence on the SQ.
When I am up an running again, I will carry out my own further trials for this material.
There are a few companies offering P'holz Sub Plinths as their sale items, and the asking price of $1200+ can be found.
I am sure the uniqueness of the Water Stains on my boards give them a sonic superiority over the fluted designs on commercially of P'holz items😁
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@pindac
I'm sure we would get along great.
I've found that the choice of materials is extremely dependent on the environment. When my listening room was on a suspended floor, my old Logic DM101 (similar to Linn/AR/Ariston), but also similar to Sota (3 point suspension hung from springs) worked best at isolation when using either a low or high mass stand. Where my tables are now, foot falls and structure borne vibration aren't much of an issue. The platforms are more about preventing airborne vibration from reaching the platter and arm, and also about the ability to precisely level the plinth and platter.
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@mijostyn
I don't need that kind of isolation. No structure borne vibrations make it to the plinth. The sub floor is a cement slab. Springs of any sort do not provide any positive sonic benefit. In any event, if I did need a suspension as you describe, I could always go back to my venerable Logic DM101 😀
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@vinylzone We would get along mighty fine and dandy, with the inquisitive nature shared between us about materials used for structures to support TT's.
I am still trying to learn if the choices are just restricted to the choice of the materials, or additionally the environment the materials are used in to produce a structure.
I have taken other selections of materials to other homes, and the ones I thought were going to be the preferred ones by the assessors, have been the least attractive selected on the day, to which I have been in agreement, 👨🎓👩🎓, more clever types might be able to help with that conundrum.
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@pindac
I have tried glass, marble, and granite in the past, but not with this plinth. I have found MDF to be preferable to either of those materials as a base shelf material. However, I don't have a suitable sized piece of MDF right now to use as a base shelf.
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@vinylzone , nice work! I would like to make some suggestions. Hang the acrylic plinth from towers placed at the for corners. Depending on the mass distribution of the turntable you will probably have to use different rate springs at each corner the goal being for the plinth to bounce straight up and down at about two Hz. You can get an idea of the differential by putting a scale under each corner. Ten put the whole show under an acrylic dustcover. You can probably make the towers out of acrylic also. Could be a work of art. Look at and old Basis Debut or the Sota Millenium to get an idea. I don't want to be a PITA (yes I do) but you deserve a better arm.
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@vinylzone Thank You for the information and the knowledge of your exchanging the Plywood Board to the Substantial Piece of Maple Wood.
If a an additional piece of Acrylic is available of a suitable dimension, a option will be to consider a CLD Layer at this position in the structure, the doubling of the thickness will improve the structural property and it should be able to take the added weight of the Maple.
Acrylic in 8mm thickness has measured very favourably for damping and dissipation when assessed as Plinth Material, I am awaiting to see further measurements when it is used with a 0.8mm thick, double sided Teflon Tape.
As a First Tier in a Sub Plinth, the CLD design could prove to be quite a valuable choice.
I use Cork Footers under a 30mm Thick Granite as my first Tier, and have one other not so commonly used material as a Tier sandwiched between Granite and Plinth with Two different design footers separating the sandwiched Tier.
@holmz The additional information and the variety of thoughts offered from different end users, is always a welcome way to extend ones understanding and knowledge of products used.
Being too insular in my experience is not going to bring inspiring discoveries.
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@pindac
The plywood board has been replaced with a 1 3/4" maple platform spiked to the wall shelf. It had some scraps around that just happened to fit, and was intended to be temporary.
The second piece of acrylic was also the temporary shelf material. I have not decided what to replace it with It is too thin to support the weight of the new wooden platform and the heavier plinth without bowing slightly. But that's more of a practical issue than an isolation issue, I'm not having any issues at all with any structural vibrations reaching the plinth.
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Not a Trekkie, but more of a techie maybe?
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Townshend Audio offered their damping trough separately in the late-80's/early-90's. I've never seen one for sale used, but one could be taken off a "sacrificial" Townshend Rock table and used on any other design. The cheapest Rock to find used is the Mk.3.
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Looks like the study of the Vintage Models has brought the 'Trekkie' fan out as well 😀
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It contains images that will surely get the creative thoughts working overtime.
…
The Through Section of the JVC shows a substantial material has been selected for the Chassis and the walls and base of the Recessed Bowl.
Reminds me of a hemispheric resonator gyroscope.
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thanks @rauliruegas
There's actually a Townshend rock group on facebook that is run by a guy called Matt McNulty - very knowledgable. Sadly Max passed away recently and he was always open to discussion. I have a copy of the Bugge Thesis and Max was happy to let me share it. It's genuine scientific reasoning - not the usual quackery. The interesting thing was that it hints to the fact that bugge wanted to use this on a direct drive turntable motor unit. I am gonna do it with a Sony TTS8000
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@holmz This is one link I had forgotten I had bookmarked.
It contains images that will surely get the creative thoughts working overtime.
https://www.avsite.gr/forum/threads/dd-turntables.178381/
The Through Section of the JVC shows a substantial material has been selected for the Chassis and the walls and base of the Recessed Bowl.
The Bowls role is usually to house the Stator and additionally is used to support the mounting of the Platter Bearing Housing.
I have seen a selection of DD TT models that I have shown an interest in that has a wafer thin bowl wall material as a comparison to the JVC.
I have also informed a engineer friend who had one of the models with a very thin bowl material and the outcome of their investigations was that a flexion has been occurring and this energy is most likely to be received by the Cartridge.
The flexion will also show as an eccentric rotation and this a independent speed strobe will show the eccentric rotation will impact on Speed Stability.
The eccentric rotation will also impact on the stylus interface within the Groove and will most likely be a cause of a distortion.
Such conditions that are transferring energy to the Cart’ and impacting on the Cart’s Geometry when in the Groove, when present, will not enable a Hi End Tonearm and Cartridge to perform at their best.
The cost associated with such ancillaries and the compromised environment they are potentially being used in, will hopefully have been identified in advance by the user and have been accepted as an acceptable condition to continue with.
There are methods known for a recess bowl produced from a poor quality material, to make a recess bowl and bearing base rigidly secure and substantially decrease deflection, maybe even eradicate it.
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@holmz The link is a worthwhile read, Juergen contributes within this thread on a selection of his owned TTs.
There are other long term users of other Brand Models who offer reports on the impressions that have been made.
It has a good selection of commentaries on a range of Vintage Brand TT's with different motor drives in use.
To get the maximum benefit of the reports, a right click usually works, with the selecting translate on the pop up tool bar, it might have to be repeated as the pages are changed.
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@vinylzone The Self Built TT, looks very nice, the Acrylic or Polycarbonate Plinth Material is a nice touch.
The Acrylic when used as a thinner sheet and assembled to be used as a CLD Structure has produced quite attractive damping measurements.
I am sure the CLD structure will not have the same aesthetic as yours if clear sheets is used.
As for structures, I also see a further thought has been given to the Sub Plinth Structure as well, I have been carrying out investigations into assemblies across the years and have been quite surprised by some of the discoveries made.
It is interesting how a Plywood Board has proven itself as a Tier in a Structure and is seen on a regular basis used as a Tier in a structure under a TT.
There also appears to be an additional two Tiers of Acrylic used in the structure, this also of interest to me.
Have these materials been selected through trialing them for their impact on the SQ being produced, or are they used as the initial design for a support structure as they were readily available.
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@holmz if you really want the best you could start looking closer to home at the “Commonwealth“ rim drive TT‘s built for Australian broadcast use. Come in 12 & 15“ versions, rare as, and not cheap when you do find one. Stereonet has some chat you could google up
built like brick …..only stronger…make Garrard 301 look like hello kitty record player…
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I went a different route. I used the motor housing, platter and bearing from a VPI TNT 4 and built my own plinth. I also used a 300 RPM Hurst motor and VPI's one speed pulley. Feet are also VPI for now . The plinth is 21"x16" and 1 1/2" thick.
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This could be interesting for SOTA TT owners:
R.
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@holmz : Both are entry level items, SAEC had four other tonearms a top yours. In the early 80's the top of the line had retail price in Jpan of 108,000 Yens and ours 52K and the 308 48K Yens.
In the other side and if you own the Saphire ( you did not say it when posted. ) model maybe could be a good time to send to SOTA or at least ask if exist important up-dates between your unit and the today Saphire model and then keep the SOTA TT change that tonearm and build an external arm pod for your second tonearm and that's it.
In any case you will need ( if you don't have it yet ) a good after market platform where the SOTA will seated isolated of vibrations/resonances and even that the Saphire has the vacuum hold down characteristic try to find out " dead " weigth of 200-300grs as a TT clamp even that you could think is redundant it's not and helps.
R.
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