A Copernican View of the Turntable System

Chris,

As Raul and Halcro suggest, three seems the magic number. They have obvious advantages in making things level and stable (as with the tripod in general) and you can easily adjust the height of each individual AT616.

Hope that helps

I use just 3 tiptoes Chris.
Rigid de-coupling like spikes are far easier to ensure levelling with 3. With 4 you'd probably find that only 3 are making solid contact.
With isolators that use rubber or other 'giving' substances, 4 can often make contact if you want utmost stability ie if you don't want it to tip if you lean on it?

Halcro, the Empire is equipped with a belt, and an extremely robust drive motor, one that is just about unstoppable. The speed of this machine is so stable that the usual effects of soundstage drift due to speed variation don't seem to exist- its soundstage is a lot like that of reel to reel.

I am of the opinion that a robust drive is what is important, more so than the *type* of drive. If it is wimpy it will not matter what kind of drive it is!

As a result, if you look at vintage turntables, you will see a following around certain models that were better at getting things right than their competition. All of these machines have very robust drive systems too- the Empire, the Garrard 301, the Technics SP-10.

I think this topic was covered elsewhere.

Dear Ct0517: With TTs I always used/use it three 616 footers . Normaly you don't need four exception with the heaviest ones.

Remember that each footer has a weight range from 2.5kg to 15kg.

Regards and enjoy the music,
Raul.

Hi Dgob - did you try the sp10 with just 3 of the 616's.
I realize they probably come in a set of four, but being this exercise focuses on simplicity and isolation does it not make sense to use 3 touch points instead of an extra one under the sp10. 3 will certainly hold it up.

Doesn't using 4 make leveling of the TT harder?

I use 3 mapleshade brass heavy foot spikes.

Henry I believe you use 3 tip toes?

Raul did you ever try it with three. Are they only designed to be used with all four?

Curious. Thx. Chris

Banquo363,

Congrats. They certainly make a difference.

Dear Henry, if you want this thread to soon get out of hand, the best way is to encourage the idler-, belt- and direct-drive "camps" to start a discussion about what is the "best" drive system for turntables .....
This is a minefield full of personal preferences and highly explosive "sensibilities".
Especially so, as each and every of the popular drive principles does have special requirements to the tt-design as a whole.
Better leave this alone .... it won't do any good to the Copernican view of the turntable.
Cheers,
D.

T_bone,

Many thanks and I look forward to finding out.

Atmasphere,
Empire 208?
Hmmmmm...belt drive? I kinda figured you as an idler kind of guy?
Any comments on other drive systems?

Banquo, I have nothing to say about Copernicus, but did you ever get your SP10 squared away by Berdan or Thalmann? If not, and if it's still unreliable, IMO you should reconsider it.

I guess this is one way?
BIG
And these are others?
NOT SO BIG
Do they all sound the same?

Sorry. Premature. A little bird (and my bottomless desire to buy new audio stuff) suggested that I grab the AT 616 footers, so I did. Now hopefully my technics will stop acting up and work properly so I can try these out.

FYI: a set of AT 616 footers just showed up on eBay. I would get them but my turntable repairs suggest to me I may not have a functioning sp10 to put on top of these beautiful footers. Sigh.

Dgob,
I think it was mostly stainless steel by mass but I will try to dig up that information. I have a copy made by a metals engineer who tried to copy the SAEC plinth, and the thing has three layers of different metal with slightly different resonances. It does weigh a short ton.

Atmasphere,

I think what you say about the popular plinths for the Technics seems true to my experience. I know someone who used the SAEC solid metal plinth and who still swears by it. However, shipping costs for that monster from Japan are just too prohibitive: at least for me in the in the current economic climate. I think it is also made predominantly or completely from Aluminium and so there are likely to be resonance problems. However, I'm not too certain if they went along the same route as Acoustic Signature in a mixed metal approach similar to the one you have suggested.

I also agree about the most expedient approach and that is precisely (if I follow you correctly) what I and others have been trying to do. The only question is whether instead of pinning it to a platform, using the AT616 provides a suitable alternative. This leaves the question of finding a decent arm tower and the experimentation that Halcro and others seem to be undertaking seems fascinating along these lines to me. I'll try the spikes seated on some industrial absorption material and let you know how that goes.

Thanks again

Dgob, the problem with the Technics is that it does not have a real plinth. It is built for the platter only. If you have the deluxe base, the material that the arm sits on is something quite different from that of the platter, at least that is the case in my friend's MkII.

This use of dissimilar materials shows that there was not really a concern for the matter at the time. I would say this is one of the things in 'table theory that has advanced since the Technics was built.

So in this case, you have to come up with something- the resolution of modern systems being what it is, you can easily hear the faults in the original 'pseudo plinth' system. That is why there are some fairly ambitious plinth projects out there now for the SP-10. Its a great table, but it needs a plinth to really work.

In the case of the Technics (if you will pardon the pun) it does seem that if you can separate the platter (and ditch the original 'pseudo plinth'), pin it to a decent platform and then come up with a decent arm tower, that that would be the most expedient means of creating a proper plinth.

I've had the idea of making a massive machined metal sandwich of aluminum, brass and high grade steel, that mounted the platter and had provision for the arm. The sandwich was dissimilar metals so their resonant frequencies would be different and thus self-absorptive, while at the same time maintaining rigidity.

If there has been anything about the Technics machines that has ever struck me as goofy, the 'pseudo plinth' is it. I know its similar to a lot of radio station 'tables in that regard, but they *did* pitch it as a high-end consumer machine too.

Atmasphere,

Thanks for sharing this. It clarifies your point well. I am still left with the issue about theory and practice though.

The Acoustic Signature Mambo shares your approach with increased mass and a rigid and directly affixed arm-column. It is simply phenomenal in its performance when well isolated. However, the seperated Technics/arm-column improves on specific areas. Key among these are the scale (depth, width and height) of the sound stage; the air/audible space that exists between performers and the ease with which the entire performance is resolved (leading to smoother sound at higher volumes).

I am still not absolutely certain what trade-offs might be happening and so I will explore this fully before determining if what I am hearing is just different or actually 'better'. One thing for certain is that it is a dramatic difference.

The questions that remain would therefore (at least for those using pneumatic devices under one component or both to decouple the arm-column/TT) seem to include to what degree and at what specific point or level do disparities in vibration of arm column/TT impair the quality of sound produced. They might also include questions of how much does appropriate VTF compensate for any such disparities. This and - 'most importantly - the obvious difference in performance that I am getting at present are important reasons why I'll continue to experiment with the phenomenon of seperation and decoupling. As part of this, I am considering trying spikes, viscoelastic and pneumatic options under the arm column itself, as I am not wholly convinced that seperation and decoupling "must" involve disparity.

Time and my hears will tell and both can only be further assisted by the kind contributions of people such as yourself.

Halcro, here is our 'table. We've been making it about 10 years. It looks all the part of an Empire, but looks can be deceiving. The photo is from about 2000 or 2001.

http://www.atma-sphere.com/products/208.html

Dgob, I have a little thought experiment for you. You have the platter on its stand or whatever, and you have the separate arm tower. But we are going to put a vibrator under the arm tower but not the platter, and run it. The question is, will you be able to hear the result? I think you can.

That, in a nutshell, is what the issue is. There simply can be no extraneous motion besides that of the arm tracking the LP! **Any** other motion is a coloration. So if the arm tower is able to vibrate or resonate at any slight amount that is different from the platter, you have coloration. Cheesy plinths totally allow for this sort of thing- that is what I have seen over and over- and so getting rid of a cheesy plinth is likely a good idea.

But that is simply not the same as having a plinth that is properly engineered! (This is sort of the same argument that because a particular LP is scratched and warped, therefore all CDs are better than all LPs.) And you are experiencing a step towards that, as your platform for your towers is in fact your plinth. Try coupling the platter and the arm more tightly into that platform and see what happens. The more dead you can make the platform, the stiffer you make it, the better the 'table will sound.

Dear Henry, sorry to say, but the new version will rather be the "big brother"..... in all respects ;-( .....
Cheers,
D.

My apologies to Dertonarm as I have just seen images of the Apolyt turntable he designed in 1990 (google it) and it is quite stunning and interestingly, has massive independent arm pods.

To these eyes it would be a disappointment if it didn't sound as beautiful as it looks?

Will the 'new' one be a more affordable version of this Daniel? :-)

Cheers
Henry

Dgob,
I'm really excited about your experiment because I am familiar with the Mambo (not too different from Raul's Acoustic Signature model) and knowing the way the armboard is connected to the 'plinth', I believe you should experience a marked improvement if you separate it onto spikes?

The only caveat is whether it is heavy enough to maintain the stability required?

Dear Daniel,

BTW - there were turntable designers contributing to this thread.

Yes....you are a turntable designer and Raul is a tonearm and cartridge designer.

Unfortunately you must prove it with a 'pudding'?
So far we know that Ralph can design amplifiers and Raul preamps.
No 'puddings' yet for turntables, arms or cartridges?
Although I don't doubt that dessert may someday eventuate?
And I certainly look forward to your turntable debut at CES this year? :-)

Cheers
Henry

Dear Henry, yes, Korton's sculptures are sharing - although separate .. - a plinth in the platform they are standing on.
BTW - there were turntable designers contributing to this thread.
It is just that their statements weren't really to the liking of the "nude tt"-camp.... ;-) .....
Cheers,
D.

I think this is an example of separates on the same plinth?
GULP

Halcro,

I have been playing with the detached armboard and note major differences in my analogue performance. Beyond question are improvements in staging and a more refined sound across the piece (I have been playing my TT at clearly increased gain levels, which I take as one sign of this). Bass is also far tighter and more detailed.

My Mambo armboard has three M6 screw holes in the bottom by which it is screwed onto the TT by an attaching rod (apparent as the armboards base in my System photograph). If I remove that attaching rod it will therefore be possible for me to use three spikes instead of the blue tac. I intend to try this out both because the blue tac approach has provided such marked differences and to see if this puts the debate beyond question.

Atmasphere,

Just a quick question but for those of us using pneumatic footers, wouldn't that mean that the seperation of tonearm (including mount/armboard) from the nude TT represents the decoupling of both and the removal of a common plinth?

Kant demonstrated that the argument - "that might be true in theory but it is not in practise" - invariably pointed to the deficiency in a relevant theory. Maybe, if the common experience proves sufficient, we will find the reason why. That seems to be the way of progress!

Please accept my question as a genuine search for an explanation for what appears to be happening and all the best with your TT launch.

Greetings Ralph,

my turntable has been in development since the early 1990s.

That sound exciting? I was wondering why no turntable designers were contributing to this thread?
Any clues as to which 'drive' model you're pursuing?

Halcro, points are a sort of mechanical one-way diode. That is they are fairly efficient at transmitting vibration in only one direction. So if your points are pointed *down* under your tone arm: welcome to your plinth, the anti-vibration platform.

Any good anti-vibration platform will have both 'acoustically dead' and 'absolutely rigid' as a mantra.

I agree that a bad plinth is likely worse than none. I've been down this path before- my turntable has been in development since the early 1990s. So the comments I've been making are based out of experience, not conjecture.

If you want to separate something, and if the 'table is not a direct-drive, then the motor might be a better candidate. However IME the vibration of the motor will be of no significance if the plinth works right.

We're baaack.....

I re-assured the moderators that I really didn't take my pet snake for a regular walk..........it's just a special treat.

Whilst the thread is not on the front page of the Analogue Forum, if you go to the Recent Discourse Forums and press 12 hour, 24 hour or 48 hour link, you will find it there.

I like going this way as a routine b cause you get to see all the current discourse and in their order of popular activity.

However I have asked Audiogon the reason for this?

Dear Chris /all: The " naked TT project " is similar as what happen with the MM/MI alternative: many people are trying/testing with no posts in the threads.

Both alternatives are so un-expensive and so easy to achieve that IMHO it is an audio " waste/lose " not to try it, at least just to " cover up a hole in our audio culture ".

Btw, Banquo363: from the AT operation manual the AT616 works between 10-60kgs. It works for me and for Dgob too.

Now, each 616 footer is a set of three internal and independent insulators design where the third one works when the item weight is over 30kg.

Regards and enjoy the music,
Raul.

T_bone,

I have been trying my stand alone armbase for the past three days and it has not moved, despite my having been deliberately more robust in handling than I would normally. Unlike Halcro, my armbase (as can be seen on my System page) is only held in place with a few blobs of blue tac. I did take some time in adjusting to ensure that arm and cartridge were perfectly aligned with the detached nude TT but after that I have treated the entire exercise as if it was a normally fixed arrangement. As you know, I'm using the AT616 pneumatic footers and so that might be encouraging if the results althmore surprising for that.

It is too early to be certain of all my findings but I would honestly (and VERY unexpectedly) say that you should just give it a go. The differences are blatant, to me.

Dear Chris, I should be picking my sp10 up tomorrow. It took awhile because I kept adding stuff for Mirko to do. I'll have a tonearm pod a la Halcro which will sit on these cool feet he originally designed to replace those on the Microseiki Rx-8000 motor unit. And evidently the speed was fast at 78rpm so I told him to replace all the capacitors--I hope that fixes it, even though I don't have any 78's. The noise I was hearing was the thrust bearing, whatever that is, and he replaced it. If everything goes well, I should have a pretty good set up.

Dear T_bone and Dertonarm: thanks for your notes regarding the footers. That's what I would have thought, even though I didn't know the theory behind it. But Raul asserts the AT 616 sound great beneath his 'light' sp10. Here again we have a tension between theory and observation. No matter to me: I'm still buying them just to see, that is, if they ever come up for sale. In the meanwhile, I was looking at Edensound's terrastone footers. Has anyone tried them? One can go broke trying out all these different footers; might as well buy a plinth--ha!

This thread doesn't show up on my front analog forums page either. Annoying.

"post scriptum: I wonder why this thread has to be searched for and isn't available anymore through the Analog Forum's front page ... any idea anybody ?"

Hope it doesn't have to do something with "my finding the mice" talk in my last post :) Has anyone figured this out yet?

T Bone/Dertonarm – thank you - excellent advice on the weight considerations for these footers. I hope that the talk on here about those footers doesn’t cause their market price to skyrocket now. If it does we know who to blame.

Halcro,
I think Ralph would say we are all three in agreement. To me, a 20kg armpod spiked to the same platform that the TT is spiked to means they are strongly 'coupled', even if you can take them away and walk them with your two pet snakes, separately.

Dear Halcro, T_bone and Atmasphere only seem to postulate opposite positions. Whether you actually mount with screws or with spikes and high weight can result in the very same.
So your spikes are actually VERY tight a coupling to the platform (even if you can move the armpods if you wish...). The coupling force is the weight of the armpod (hopefully pretty high) divided by the touching area of your spike (very small ... ) - so the resulting coupling force is pretty high.
However with the kind of weight we are talking generally in audio components, spikes are less tightly an mounting option than a good solid screw. After all it is about coupling two masses together without possible movement of one in relation towards the other.
Armpod(s) and bearing/turntable can hardly be DECOUPLED from each other in the sense that would allow relative movement of one towards the other (which would be the very sense of "decoupling"). One can incorporate kinds of resonance-barriers between them, but they will always (or better: should...) be coupled towards each other.
This can be via a shelf, plinth, skeleton - whatever.
I think T_bone, Atmasphere, (me too ...) are talking about the very same thing in slightly different word.
Cheers,
D.

T_bone,
What you are saying and what Ralph is saying seem to me diametrically opposed?
You and I are in total agreement, in fact the postulation of this thread is that the armpod is fixed and the geometrical relationship to the platter is correct and stable.
What Ralph says is

mounting for the platter and the tower for the arm will sound their best when coupled as tightly to the non-resonant platform upon which the resulting turntable is being constructed.

Coupled TIGHTLY to the platform!!

Here I am simply going to be obstinate.
I disagree completely. There is nothing TIGHT about the spikes under my armpods and there is nothing TIGHT about the TipToes under my turntable.
The armpods and turntable are DECOUPLED from their base (the shelf) and unless I'm not comprehending properly......you agree with my methods?
Bear in mind that the RELATIONSHIPS must be completely accurate and stable.

So DECOUPLED are all these items from each other, I can physically take each armpod away and if I so desire, I may even tuck my Nude Turntable under my arm as I happily walk my pet snake?

Dear Halcro, yes - it is on your front page, but not on the "Audiogon forum analog"-page.
Means that one indeed has to search for your thread - it can't be find among the current other threads in analog.
Very strange indeed.

Dear Dertonarm,
Thread is visible on my front page but Raul also couldn't see it?
Don't know what's going on?

T_bone is absolutely right - any damping (pneumatic, oil-based, elastomer - whatever) will only reach its optimum read: lowest possible) resonance frequency and spec behavior at its maximum load.
So here for once any over-compensation regarding parts is not just futile but entirely contra-productive.
That's why even most high-priced isolation platforms do need additional load in addition to audio components resting on them to really "work" the way the are designed for.
Same regarding the other points in T_bone's post. They are correct and describe the correct way to handle the topic if going for a TT without "classical plinth".
Cheers,
D.
post scriptum: I wonder why this thread has to be searched for and isn't available anymore through the Analog Forum's front page ... any idea anybody ?

Halcro,
Regarding your last post of 1/27, I think the 'theoretical proof' that Ralph offered earlier in the thread more than covers the issue regarding the desirability of having the tonearm mount absolutely stable in space vis-a-vis the turntable platter axis/level. Any movement between the two will show up as distortion. There is no getting around that.

If I were going to decide to 'go nude' with an outboard tonearm pod... I would...
1) build a tonearm pod (or three) like yours - I think it is a great design - VERY heavy with threaded bottom allowing one to spike it to a platform,
2) mount the nude TT to the same platform that the tonearm pod was mounted to, probably using the same spikes as on the tonearm pod,
3) I would put pneumatic footers, if any, between the 'platform' and whatever it was mounted on.

Banquo,
As regards putting 'light' objects on pneumatic footers with very large weight limits... I think the value of using pneumatic footers is to reduce the resonance frequency of the mounting to as low as one can in both the horizontal and the vertical. If one mounts a 10kg object onto 3 footers which can EACH carry 10-20kg, I expect that would be a problem. I have found when I have used platforms and pneumatic/magnetic isolators that it is always better to be at the heavy end of the range rather than the light end.

Dear Chris,
Thanks for the kind words and yes....kudos to Raul for planting the idea for the 'Nude Turntable' in my head.

You may be right about lots of other people now trying out the same experiment as my Thread is recording an average of 100 hits every day despite the fact that it doesn't appear on this site and they have to go searching for it??!!

Hopefully some of these 'experimenters' will eventually contribute their thoughts in this Forum?

Knowledge is free.

Dear Banquo - I forgot to ask in my last post how you are making out with the repairs on your sp10 ?

Also - maybe one of the members here can hook u up with a plinth to try to compare with your current setup ?

Dear Dgob – Looking forward to your impressions of how the sound changes when you isolate the armboard. I did not see any value myself in attaching an armboard to a surface containing a motor and vibrations so I went directly to an isolated armboard. If the improvement that you noted was based on this alone - I can’t imagine how much better? your next step will bring. It also speaks volumes to the top end component that an sp10 is.
I really believe the SP10 engineers didn’t realize how good they made it. Think about it – they didn’t know what type of structure alias plinth - the broadcast studios were going to put them in - so they made them “bullet proof” to work great without a plinth anywhere. They had to - they wouldn’t have become the standard worldwide if this was not the case. Conventional wisdom said put it in a plinth so they made plinths for it as well to sell. This is the same reason I started with a plinth - go with the flow. It took a lot of courage Raul to keep up the front on your side. Henry it was your thread with the pictures that got me going. Kudos to both of you. I am listening tonight and I can’t believe the sound.

I have a seasonal summer cottage in the woods. This whole thing is starting to remind me of catching mice except in a good way here. For every mouse that you catch there are ten-fold and more lurking somewhere else in the structure. As we speak there are probably “x00’s” maybe "x000's" of folks trying this out as Raul has referenced. If the thought of this is forcing some folks to cringe and hide or talks words around it so be it. My SP10 and ET arm hasn’t fallen over yet. Hearing is believing as Dgob said. Something tells me they are all trying or planning on trying it too really soon - they just are not saying anything ………yet :) This is just too big a deal for us turntable people to ignore or talk words to.

Cheers Chris

Dear Halcro: You are IMHO spot-on in your last two posts.

On the first " plinths "+ subject we need to think " too " that not only the floor works as a plinth but the Earth's nucleus too!!!!

In the other side a debate exist only because the ones that are argue and argue and argue does not try yet the whole " naked project ".
At least we advocates to the naked project have targets like: improve the quality performance and through that project we taked a step forward in that direction and we all are enjoying the music better than ever through that project when the people that are argue are enjoying almost nothing because IMHO no one can enjoy that kind of " words/bla bla ".

So what they have on hand?, almost nothing to argue but theory that can't prove through real experiences.

In the other side day by day are growing up the people number that are testing the naked project and till today everyone of them are satisfied with this alternative against the other one.

Welcome Banquo363!.

Regards and enjoy the music,
Raul.

I think you will find that the mounting for the platter and the tower for the arm will sound their best when coupled as tightly to the non-resonant platform upon which the resulting turntable is being constructed.

Pure supposition and theory with no proof or evidence offered?
This is not worthy of you Ralph.

We 'Nuders' and 'Armboard Isolators' are reporting our practical experiences.
It is slightly galling to be told that 'theoretically', in someone's unproven opinion our experiences are invalid?

that the platform has become your plinth

Well OK...... then turntables with plinths which sit on bases have two plinths?
:-)
Let us agree that at least we 'Nuders' are eliminating one plinth?

And does that mean our amps on shelves or stands also have 'plinths'?
And our tuners, CD players etc?
How about our 'plinthed' speakers?.....because they sit on the floor or stands?

I think you have to understand the lengths that most of us go to, to de-couple and isolate our speakers and turntables (and many also their amps), from this shelf/stand/floor/plinth.
If you look at the transmission of various frequencies through the tiny contact points of 'spikes' or through various decoupling materials used as isolating bases, it becomes apparent that this differs enormously from that of the contact made by the turntable in its traditional plinth.

I have heard that Ralph's famous amplifiers do in fact sound better when mounted in a Panzerholtz plinth :-)

Of course there will be an "improvement" when you go to the bigger feet. This stuff has become so subjective and so uncontrolled (in the scientific sense) that there is a huge placebo effect. If you are prepared to like it, and if your turntable does not actually fall to the ground, then you will like it. This is in no way meant as an insult to you personally. It's just a part of this crazy hobby.

I see your larger point, Lewm, but really I'm not prepared or fixin' to like any particular kind of configuration. True, I expect the larger feet to make some difference--why shouldn't I since I'll probably end up paying a chunk of change for them?--but whether I prefer that change or not is up for grabs. After all, they'll be easy to sell. Placebo probably would play a larger role if one couldn't sell after trying.

I take a very practical approach to this plinth(less) issue. My table didn't come with an attached plinth, and since I found it to sound pretty darn good without it, I'm sticking with it for the time being and trying out closely related configurations. I can honestly say that if I had some plinth ready to hand, I would immediately try it out to see what difference it makes. I take it that Chris's and Raul's point is to suggest the converse: if you have a plinth, take it off and see what happens--you may be surprised.

In my opinion, that minimal kind of experimentation won't settle the larger debate, but it might transform one's picture of the debate. However, I agree with Dertonarm that even if we had many hands going up saying that their experiment led them to believe plinthless is better, it would still leave a rather large hole in our understanding of why that is (if it is at all). There should be some 'reflective equilibrium', as the philosophers say, between observed findings and theoretical explanation. Pure theory and a rhetorical reference to 'physics' and what it allegedly tells us is pointless when it flies in the face of repeated observation; conversely, 'mere' observation is empty because it just gives us data points without a theory to tie them together.

At any rate, Yahoo Japan is not easy to navigate. Are there any other options to find these feet? I've been perusing Hi-Fi Do Japan. Very cool site--but alas no feet as of yesterday.

Rauliruegas, OK let's go with that for a moment. You hang it from the ceiling- where is the tonearm? Hanging also? On a separate string? Obviously *that* is not going to work...

So, you have to connect them together somehow so the sacred geometry is maintained. And that is just so tracking errors are minimized. So how are you going to do that?? A platform? Now the signature of the platform is the signature of the system. You could use some sort of bar or strut to hold things, again, any signature in them will be heard.

So the model does not seem to hold up.

Dear Atmasphere: Yes, that could be a " plinth " but that is not the subject here but the TT naked it self .

In this same thread I posted that we always can hang on the TT from the ceiling and now what : the ceiling is the " plinth ".?
The subject is way different.

Regards and enjoy the music,
Raul.