Tonearm mount on the plinth or on Pillar ?


Folks,
I am looking to buy a custom built turntable from Torqueo Audio (http://www.torqueo-audio.it/). They have two models, one with a wide base plinth where the tonearm would be mounted on the plinth (as usual) and the second is a compact plinth where they provide a seperate tonearm pillar to mount the tonearm. According to them the separate tonearm pillar version sounds more transparent and quieter because of the isolation of the tonearm from the TT. My concern is whether seperating the tonearm from the plinth would result in a lesser coherence in sound ? Isnt sharing the same platform results in a more well-timed, coherent presentation ? Any opinions ?
pani
Atmasphere thanks for that info. Something is not clear to me. Maybe it's just me. Did you actually permanently mount a tonearm to the lathe ?
     
You said.

What we discovered is that the arm mounted on the pillar was giving us more noise than the same lacquer played back on a Technics 1200 sitting nearby.

Just so I understand, you attempted this in order to make your business of cutting and testing playback more effective and efficient. I can understand that, and you have discussed the Technics SL1200 with Grado cart in another thread. Now you said in regards to the tonearm mounted in the pillar next to the lathe. 


IOW, it was not suitable for actually telling if our cut was truly silent, set up in this fashion.

So it generated noise, which in your line of work is how you pass or fail the discs that were cut. This is my understanding of what you are saying.   

But then you said.

By coupling the arm directly to the plinth in which the platter bearings reside the issue was solved.


So. Are you referring here to playing the cut disc back on the nearby technics sl1200 in your work environment ? or did you actually mount the tonearm that was on the pillar directly to the lathe plinth?

********************************************************   

btw - thanks for the great information on my question about the angle of the disc cut.

Pani (OP) sorry, but if I may digress for a moment...

It is consistent with the info I have received from talking with people that do this work over the years. The very important part of the information to me, is that the angle of the cut varies. The angle that the cutterhead is placed at when a disc is cut, results in an included angle in the final disc. This included angle must be duplicated with the reproducing stylus or distortion will result. I think everyone is ok with this right statement ..right ?

Now Halcro (Henry) said

I'm not sure that the cutting process tests can be transposed to the playback field.

The angle of the cut varying on the cut disc; applies directly to playback of the actual records we buy.   
 
Let us think about something.  
We all own multiple copies of favorite pressings. Have you ever noticed how lps from the same era, country and plant can sound different ?
The stylus life as Atmasphere said is based in hours. And when it is replaced it is never set up exactly the same again. And the cutting stylus puts that included angle in the disc. If that angle is not duplicated on the records we buy, you will get something on playback that is different than what was originally cut.  And it can vary with record. So to those that like to use a USB microscope to set up VTA/SRA .....?  thats another thread discussion. It does bring up importance of correct VTA on the fly (imo).  

So what .... 
To me it means the skill of the lathe operator is very important.  Imagine that same music being done on different brand lathes, different countries, different eras....
All the great engineering work that was done to capture the original recording on tape or file;  can be lost if the guy/gal doing the cutting is still learning how to do it. Sorry to ramble. Fascinating stuff.

Dear @atmasphere /friends:    

"""   The entire arrangement has to be by definition rather dead, else sounds in the environment can affect the cut............ 

IOW, it was not suitable for actually telling if our cut was truly silent, set up in this fashion.

. I hope this gives you some idea of how easy it is to measure this!.....

  

Now I understand this is bad news for some and as a result there will be those that think that somehow these principles don't apply to their machine. It is true that I did not make the measurements on anything other than our lathe,...............

 if the arm is anchored to a point that is able to move with respect to the platter. ..........


I think that we have a problem here:

your target in that tests and your " intuitive " premises are way diferent to our audiophile main targets and premises. So, your conclusion is not conclusive about what we want to test UNDER DAY BY DAY LISTENING ANALOG EXPERIENCES and that's why for you is so " easy to measure ". Your methodology can't fulfill our audiophile targets and premises and can't help us because the your " vision " of the whole subject is overall limited.

No, your news are not bad news for me, your news does not affect me in anyway because diferent targets.

Audiophile DAY BY DAY LISTENING SCENARIO means ( between other things. ):

- DD and BD TTs in the audio system.
- Diferent tonearms and cartridges.
- Some systems using tube technology and other SS one.
- Diferent type of speakers that " dissipate " sound in diferent ways. Some of the systems using subwoofers.
- Normally we don't listen continuously at 95 db SPL. We use variable SPLs even in the same system.
- Each system room " dissipate sound waves in different ways. We have not an " anechoic " room treatment. We just have a decent rooom treatment and not always.
- All of us listen everykind of music. Jazz, classic, pop, country, rock, etc, etc. where each one of kind has different needs ( SPL ) with sound waves that are different.
- No one of us has a dead silent platform, plinth or the like.


and I can go on on many other " premises " we have to take in count, even to use the " right " external tonearm pod/tower

So, I think that we want " more " than your " easy measures ". In my case I want to know where is the SPL ( if exist. ) umbral where the theory start to reflect the " damage " creating ADDITIONAL colorations/distortions because the non-integrated TT tonearm approach.

For me seems not so " easy " but the other way around: huge complexity.

Anyway, it's obvious that even that you could considered an audiophile your self we are way different or just ignorants about. At least me.

Regards and enjoy the music,
R.








Dear @pani: Now that you have several opinions on your main subject thread: which was your choice?

By the pictures that italian TT design looks beautiful/gorgeous ( Italians are very special people on good looking design, anything. ), especially the one with  the stand alone tonearm pillar that between other advantages gives you the opportunity to mount 2-3 tonearm/cartridges at the same time in the TT.

Today, other than audiophiles,  I can't think that  all the TT/tonearm manufacturers that choosed the stand alone fashion are just wrong.

Till today no one over the net proved it, no real facts.

So, the " ball " is in your " field " now.


Regards and enjoy the music,
R.


Peter Breuninger states that he "would put this combo up against anything currently available" (scroll to 6 mins 50 secs on the readout).

Looks good enough to be Italian too. :)

It contravenes a lot of currently "fashionable" logic e.g. not putting the drive pulley right next to the platter which would have maximised belt contact around the circumference.

Shame he only plays it for a minute. ;^)

Although I’m not a believer, I’ve got to be honest, despite the brief exposure it did sound good. :)

(They do also make models with the linked chassis BTW....)


https://www.youtube.com/watch?v=Gdo2Yf3BArQ

First we're told, **All we have to do is place the turntable in a room with speakers playing loudly and then measure the output of the cartridge.**

Then, **As to sound pressure- we get about 90-95db of noise going on when mastering. The vacuum system is enclosed in its own chamber, but still makes noise when in operation.**

All of the above?

Yes.
So. Are you referring here to playing the cut disc back on the nearby technics sl1200 in your work environment ? or did you actually mount the tonearm that was on the pillar directly to the lathe plinth?
It seems most expedient to answer this question- the answers to both parts is 'yes'. The pillar got abandoned- currently we are designing a machined bit that matches the shape of the lathe's plinth so we can bolt the arm mount directly to the lathe. In this fashion it will be impossible for the base of the arm to have movement different from that of the platter bearings.

I don't see how attaching the tonearm to the plinth can affect the 'noise'?
Surely the 'noise' is a function of the isolation, the tonearm pod mass, fixity, density and material selection as well as the tonearm rigidity.
I've explained it twice in this thread already. What part of my prior explanations are unclear? The 'noise' is actually introduced when the arm and platter bearings are able to move in different planes and rates. This is what happens when a separate arm pillar is employed.
your target in that tests and your " intuitive " premises are way diferent to our audiophile main targets and premises. So, your conclusion is not conclusive about what we want to test UNDER DAY BY DAY LISTENING ANALOG EXPERIENCES and that's why for you is so " easy to measure ". Your methodology can't fulfill our audiophile targets and premises and can't help us because the your " vision " of the whole subject is overall limited.
Actually this is not true. First you have to consider that we have audiophile intent- which you have to have if you want to do a decent job mastering an LP! Second, I think you are confusing the cutterhead with the lathe itself. The lathe is a first-class turntable that outclasses most turntables ever built, and obeys all the same physical laws. This is why adding a tone arm for playback faces the same issues as any other turntable.
In my case I want to know where is the SPL ( if exist. ) umbral where the theory start to reflect the " damage " creating ADDITIONAL colorations/distortions because the non-integrated TT tonearm approach.
As previously mentioned, I have explained this twice already in this thread. I suggest you re-read my initial posts and then ask me questions that might clarify some of the points made.
Well, Ralph, your explanations are perfectly intuitive to me. 

When I replaced my TT plinth, a rigid coupling of the platter bearing and the tonearm seemed intuitively obvious - I used a sandwich of heavy, precision aluminum plate, with the bearing surfaces machined into a high precision match. Improvement was not subtle.

Your calm is admirable.

 

I've explained it twice in this thread already. What part of my prior explanations are unclear? The 'noise' is actually introduced when the arm and platter bearings are able to move in different planes and rates. This is what happens when a separate arm pillar is employed.
 

But what you haven't addressed at all, is a description and photo of the separate arm pillar you employed.
You apparently believe that all separate arm pillars are the same regardless of size, weight, construction, density and supports.
The only reason an arm pillar can 
move in different planes and rates
is if it is inadequate.
And failing your willingness to describe the arm pillar you employed in your tests.....It's apparent it was 'inadequate' for the purpose.
Dear @pani: Now that you have several opinions on your main subject thread: which was your choice?
Dear Raul, the fact that this question occured to me even though I am a layman when it comes to technicalities of analog playback is an indication that I value that ultimate coherence of sound over the last word in transparency. Some of the most coherent and musically correct sounding decks I have heard, all have tonearms mounted on the plinth even though they have all the engineering prowess to build a seperate tonearm pillar. The simplicity of an integrated design brings about a simplicity in reproducing the music too IMO. I only wanted to confirm it by this thread. I am happy that there are many more who think like me including an audio designer like Atmasphere. If I was allowed to try the seperate tonearm pillar + plinth I would have happily taken the trial and come to a conclusion but when I am buying blind I will go by the proven practice of getting a single wide plinth with tonearm mounted on it.

Thanks everyone for this lively discussion. Please continue if you would like to.

Pani,

I was about to start a pod style build and now find this thread particularly frustrating with lack of any hard information. What was this pod that Atmasphere used and how is this motor noise relevant?  We assume, but don't really know if the separate pod was even used on the same isolation platform.

**According to them the separate tonearm pillar version sounds more transparent and quieter because of the isolation of the tonearm from the TT. My concern is whether seperating the tonearm from the plinth would result in a lesser coherence in sound ? Isnt sharing the same platform results in a more well-timed, coherent presentation ?**

Timing and coherence were not addressed. Perhaps other people who use or have used both styles of arm mounts could comment.  I suspect results vary greatly with individual application. Apparently the people making and selling the table you're considering think it sounds quieter and more transparent with a separate arm mount. Their conclusion about quieter does not conform to Atmasphere's rules. Think it's just a sales pitch to sell separate arms/pods and more expensive set ups ? 

With lack of evidence to the contrary, I would take their statement at face value. Maybe you should get in touch with them and ask them to elaborate about these differences with these tables and its significance.

Regards,

 

Pani,
Perhaps you should take note of an audio designer who actually designs and sells tonearms and turntables.....
Someone like Frank Kuzma who makes the 4 Point and Airline tonearms and whose top-of-the-line turntable uses a separate armpod.
I’d be hesitant in calling Frank a fool....

Dear @atmasphere :  """  Actually this is not true. """

You are totally wrong because I'm asking for normal day by day listening enviroment in real home audio systems, I don't care about lathe or about your self targets. YOUR TARGETS ARE NOT THE AUDIOPHILE TARGETS. GOT IT?

"""  As previously mentioned, I have explained this twice already in this thread. I suggest you re-read my initial posts """

YOU EXPLAINED NOTHING WE AUDIOPHILES WNAT IT TO KNOW, so useless.

If you want the right questions to you then comeback with the " overall solution " that can gives us what we want to know not what you want to know or what you want to support, you are biased to your soluition/targets that are diferent from what we want to know.

Enough, you are in a way different " tv chanel ".


Regards and enjoy the music,
R.



Dear @pani : """   who think like me including an audio designer... """

well, with all respect to him and you he is not a regarded TT/tonearm designer and for his posts neither an audiophile.

Please read the @halcro last post.

Btw, good that you was decided to know what to buy before you posted this thread. Tell us how good performs when received because looks very good.

Regards and enjoy the music,
R.
Pani,
Perhaps you should take note of an audio designer who actually designs and sells tonearms and turntables.....
Someone like Frank Kuzma who makes the 4 Point and Airline tonearms and whose top-of-the-line turntable uses a separate armpod.
I’d be hesitant in calling Frank a fool....
I am not challenging anyone’s hearing or designing capabilities. I am only saying that if I have to buy blind I will buy an integrated system rather than separates.
You apparently believe that all separate arm pillars are the same regardless of size, weight, construction, density and supports.
The only reason an arm pillar can
move in different planes and rates
is if it is inadequate.

They all have one thing in common: they relay on the surface on which they rest. If this surface has any motion that allows the pillar to move in a different plane than the bearing of the platter, it makes no difference how well the pillar is constructed. Its a basic engineering flaw. I have explained this before.
What was this pod that Atmasphere used and how is this motor noise relevant?
We are not talking about motor noise here! Please re-read my first two posts- I am wondering though if I need to clarify in some way due to the obvious misunderstandings I have encountered!

You are totally wrong because I'm asking for normal day by day listening enviroment in real home audio systems, I don't care about lathe or about your self targets. YOUR TARGETS ARE NOT THE AUDIOPHILE TARGETS. GOT IT?
Oh I got it alright. What you don't seem to understand is that the lathe is an extremely high quality turntable- one with a massive platter, massive plinth, extreme platform and powerful drive. But a turntable nontheless, and one that stands up to any turntable made today. You could easily use it for playback only. So you are incorrect- my targets are the audiophile targets. You need to understand this, but right now I am thinking that you have an monetary investment that prevents you from doing so.
well, with all respect to him and you he is not a regarded TT/tonearm designer and for his posts neither an audiophile.
Actually this statement is false as well. It might interest you to know that Tri Mai of Triplanar was an employee of mine years ago. Further, we've been selling a turntable for about 15 years. It started as a modified Empire 208. Its expanded beyond that now and the result is we have a copycat who was a customer of ours and the price of used Empire 208s has skyrocketed on our account. That sort of influence does suggest some regard. I'm also an audiophile- that's why I do these things. Please try to stick to the facts rather than creating hearsay.

What I have been discussing here is a pretty basic engineering principle. It is not hard to understand at all. Anyone with a mechanical engineering background will agree with me instantly. I suspect those that don't have a monetary investment that forces them to resist, but this would be like resisting Ohm's Law, if you will pardon the expression.

I think there is a fly in this ointment:

**The reason is simple: if the platter has any other motion other than rotation (for example a slight up and down that might be imparted from the plinth due to room-borne vibration), if there is any difference between that and the base of the arm the cartridge will compensate (since the stylus has to stay in the groove) with stylus motion and therefore a coloration.**

Air borne vibration will hit the record/platter directly, as it also hits a plinth and arm. Any such vibration transmitted via the plinth will arrive after the event. How will this insure coincident behavior between arm and platter?

This isn't an automobile where both wheels are being turned at the same time. This is transmission of movement through time, and record rotation does not stop. It seems like this is the same old formula for sprung tables where movement must coincide.

Evidence or lack of, points to high quality and good execution as the winner. Think I'll go with Frank Kuzma and Torqueo Audio on this one.

Dear @atmasphere :  """  but right now I am thinking that you have an monetary investment that prevents you from doing so. """

Wrong again, my very little investment has nothing to do with. This discussion is not a contest, here no one wins but all, so as usually in you don't try to win but to understand to some of us that in my case have a higher ignorance level than you.

As some others posted you are intuitive more than scientific in this subject.
No one of us audiophiles have a lathe at home but normal TTs but because in your  simple  " test " you say that appears a " coloration " then in any inferior/normal home audio system things must happen too. That's what you infere but can't prove it.


"""  Actually this statement is false as well.   """"

could be but I think that no audiophile in this thread know you as a " well regarded " TT/tonearm designer/manufacturer. Please no ofense intented, for me even what you posted still no well regarded TT/tonearm manufacturer at least not at the same level as you are as tube elctronic designer/manufacturer.

Anyway, thank's for your reply.

Regards and enjoy the music,
R.
Air borne vibration will hit the record/platter directly, as it also hits a plinth and arm. Any such vibration transmitted via the plinth will arrive after the event. How will this insure coincident behavior between arm and platter?
Again, for what, the 4th time? The platter and arm must move in the same plane and frequency, should there be any movement at all. Likely this would be airborne induced. If the base of the arm can move in a different plane or frequency, the result will be interpreted by the pickup as a coloration or noise.

For this reason the plinth must provide absolute coupling between the platter bearings and the base of the arm, and also must be completely dead (free of vibration) for best results.

In the case of an arm pillar you have essentially a poor plinth. This is because the mass of the pillar will simply not be in the same plane and frequency as that of the surface of the platter. Since the cartridge is essentially the interface, its stylus must make up the difference between the motion of the pillar and that of the surface of the platter. This insures that there will be a coloration. Please note that the platter does not have to be spinning for to be measurable.

As some others posted you are intuitive more than scientific in this subject.
No one of us audiophiles have a lathe at home but normal TTs but because in your  simple  " test " you say that appears a " coloration " then in any inferior/normal home audio system things must happen too. That's what you infere but can't prove it.

Oh I can prove it alright- and I reported how that was done. It certainly is intuitive and also scientific. Sorry I didn't record the measurements; at the time I didn't think anyone but ourselves would be interested.

Raul, if I might be so bold, you are accusing me of being intuitive and not scientific, despite the fact that I made measurements and my comments derive from those findings, while those my accusers have none!! Does anything strike you as wrong with that picture??

When we were developing the Atma-Sphere 208, we started with a plinth that was really terrible (the stock Empire plinth). We found that by treating it with damping materials, it got better, but was far better when we replaced it with a plinth that was machined of solid metal. The benefits were enormous- this made the machine far less susceptible to the volume of the stereo as it was playing in the room; bass was improved and so on.  At that point the plinth was machined out of solid aluminum 0.75" thick.

We found that by installing a brace between the the mount for the platter bearings and the base of the arm that there was further benefit.  Now if the pillar theory was correct this would not happen- improving the coupling would make it worse! This is science after all.

Since the cartridge is essentially the interface, its stylus must make up the difference between the motion of the pillar and that of the surface of the platter.
"The motion of the pillar"......
There you go again. Nobody is claiming that a "moving pillar" is good but you have simply assumed that ALL pillars move because you yourself have used a 'moving' pillar (which you still refuse to disclose despite my three attempts to wrest it out of you).
A properly designed armpod sitting on a well isolated rigid base/shelf/plinth will NOT move despite your ill-informed protestations.
If I had an oscilloscope (and knew how to use one)....I would measure the three arms fixed to my Raven plinth and the three mounted on the armpods.
It would be interesting to see your arguments if these measurements contradicted your 'theory'....
We found that by installing a brace between the the mount for the platter bearings and the base of the arm that there was further benefit.
Now this is illuminating and perhaps needs an explanation from you about what you believe could possibly be 'moving' in your 3/4" solid aluminium plinth?
In other words....what did the "brace" fix that was a weakness in the solid aluminium?
This is a structural and not a mechanical engineering question and requires a structural engineering answer....

Hi Halco,


While I tend to agree with Ralph /  atmasphere, I think it would be interesting if you could do some tests.


To my way of thinking, the test can be rather simple, just lower the cartridge on a stationary platter / LP, then play music through the CD system, and measure the output of the cartridge.


If Ralph is right, then there should be more signal / noise with the stand alone arm pod. With this test, you can even see how high the volume needs to be before the stand alone arm pod is affected, if at all. Actually, if we only need to know the level of output of the cartridge, would a simple voltmeter be sufficient ?


Anyone see anything wrong with this simple test ?

Thekong's suggestion brings up an issue we haven't addressed. What exactly is the source of this vibration, and what is its relevance?

Atmasphere, you talked about a motor producing 90 - 95dB of noise in the room and described the vibrations as room borne not air borne. This sounds more like a seismic event than music playing, as if a bus or truck drove down your street and shook the house. We not only have 90+dB of noise, we also have the motor vibrations which produced the noise.

If you consider the principle involved, that is any extraneous arm/platter movement must coincide, then why is using a plinth more desirable than a base?  The best plinths are those that do not transmit vibrations, but now we want transmission?

I think the answer is in the execution. A "properly" constructed pod will not allow movement in a different plane. The base will serve the same function as a plinth only with more affective isolation. A seismic event is shaking the entire table and platform and your set up was unstable with the pod.

Regards,

Copernican, Copernican, wherefore art thou Copernican ?
 
Ground hog day come late in 2016 ...
those familiar with that thread know what I am talking about.  

But with some changes this time around - more direct experiences. 
I sometimes wonder why people are on these forums. Do you guys ever think about it ? For me it makes my morning coffee time more interesting and takes my mind off of bad investments. Did you know the chunks of brass from the billets, that I bought for my pillars years ago have gone up in value......... a lot. Who knew..... 

Now I can understand for folks like Atma Sphere who are in the audio business, that the forums represent a way of promoting their products when they state their opinions. And since the OP Pani has already made his decision......I figured lets have some fun. You guys know I like visuals. Visuals are international regardless of the language spoken.   

So up first.
Here you have not the amps and preamps, but the Belt drive Atma-Sphere turntable and Tri-Planar tonearm, that Atma-Sphere (Ralph) speaks about in this thread.

http://www.atma-sphere.com/Products/Atma-208#

I was not aware of this product offering btw. I don't get around much these days.  
 

Another interesting find.  Reed used to make an armpod.
  
I believe Nandric (Nikola) had the first one ever made by Vidmantas. I was looking for the resonance research data that was prominently displayed on his website, which showed a visual of the different resonances and their paths (integrated versus isolated parts). The info had a lot of cool lines and colors differentiating the two, with information clearly supporting the armpod.  Visual theory at its finest. 

Well guess what. The research data is gone, as is the armpod, as a product offering from Reed from what I can tell.

And now Reed sells a full integrated turntable.

http://www.reed.lt/components/com_virtuemart/shop_image/product/DSC_9267_hi.jpg

So a business move ....or something else ?

Hmmm......the search for Reed armpod also revealed an expired audiogon ad for someone selling his Reed armpod ................ :^)

***************************************************

Halcro (Henry)

You keep focusing on the pods themselves....

I am not reading into Atmaspheres' comments as you are. or maybe I am reading into his comments wrong, in which case let him correct me. After all Canadians speak a different language from those in the USA, eh ? Misunderstandings can happen.  
 
What I am understanding is based on his direct experiences with metallic bearing turntables and tonearms - in this case an original but modded Empire turntable, and Triplanar tonearm; he has concluded there is bearing movement (outside of normal movement) in both of them - this being the bearing structure itself of the platter system and tonearm. And therefore to put them to stand independently is a bad thing. So in this regard showing a picture of the pillar/armpod is not necessary as it is what is on the pillar/armpod itself - the tonearm and its bearing structure - that is the problem. AtmaSphere (Ralph) if I am wrong about this please correct me and good luck on your lathe project.

A gimbal design uses separate closed-cage bearings to allow lateral and vertical movement

while unipivots sit the tonearm on the point of a needle, allowing free movement in all directions

Maybe a discussion of the movements and therefore resonances of these types of bearing types would shed more light, as it relates to the pillar / armpod. What do you guys think ? 

fwiw - I don' t use metal bearings in my main turntable and tonearm. If anyone here reading has direct extended experience in their own rooms with magnetic platter bearings, and captured air bearing tonearms; I would be happy to share info. with you here or elsewhere.

Cheers
Hi Fleib,

In his last post, 1st paragraph, Ralph clearly stated that the vibration is likely to be airborne.

Also, if I have read it correctly, Ralph's arm pod was on an antivibration platform together with the lathe, so I would assume most of the structure borne vibration had been filtered.

Ralph, please correct me if my understanding is wrong.

Thekong, The original statement: **if the platter has any other motion other than rotation (for example a slight up and down that might be imparted from the plinth due to room-borne vibration), if there is any difference between that and the base of the arm the cartridge will compensate (since the stylus has to stay in the groove) with stylus motion and therefore a coloration.**

I suspect it doesn't matter. This seems to be more than sound pressure waves hitting the table, and we might as well be talking about table mounting in general. Why is a plinth superior in maintaining identical movement between arm and platter?  Either proximity, or lack of rigidity in table or pod coupling to the base.

We now know of at least a couple of prominent designers who have used the pod approach with "superior" results. No offense Ralph, but your expertise is with tubes and modifying an old Empire table does not qualify you as a table or arm designer.  I've modified tables and mounted arms, but I don't consider myself .......

Regards,

Dear @atmasphere : According with my very high ignorance level there are some things that goes against your " scientific " test:

- as @halcro posted one of your premises is that exist movement in the stand alone pillar. Why don't choose as premise that the pillar has no movement? what could happen at your scientific/theory?

- I have a premise too in my subjective " science ": that the holding cartridge tonearm must be aisled from the self TT " movements/vibrations " and air borne effects in order that those non tonearm " movements " can affect/produce additional distortions/colorations to the cartridge performance.

- according with your science my premise go against your theory because the tonearm has to vibrate exactly as the TT platter. So, if we have an integrated tonearm pod that does not vibrates at all then is wrong and add " colorations " by the cartridge.

- according that we need that the integrated tonearm pod/base has those same platter bearing vibrations. So, a well damped/dead one integrated arm pod is wrong and is wrong because till today exist no TT dead silent beairng platter.

- So, I infere from your science that it's better not to aisle/fuly damps the integarted arm pod. I don't know what I'm missing here but I'm not convinced that is better if vibrates evenly with the platter that if that arm pod stays deadly.

- other of my premises is that the cartridge must be " aisle " from vibrations as we can. Now, the ideal scenario for a cartridge ridding job is to make that job with no single vibrations, this is imposible to have/exist.

- starting from that ideal scenario next step could be to put at minimum all non-self vibraions that affect the cartridge job.
The bearing platter vibrations always affect the overall cartridge job as the tonearm/cartridge resonance frequency and the own tonearm additional vibrations and the feedback of all those vibrations and now we " need " that the integrated tonearm pod stays vibrating evenly with the bearing platter and this represent additional vibrations/colorations that are produced when in touch with all the other already generated vibrations because here exist a delay time on those same kind of vibrations and its amplitude are not exactly the same.

My God !!!!!!

We need additional integrated arm pod vibrations. Why and external dead silent arm pod is different of a dead integrated arm pod? 

is it better/worst a dead silent arm pod integrated or not? or is better the one that vibrates evenly with the bearing TT platter with all those additional vibrations I talked about??


For you and the other advocates to integarted arm pod things are so " easy " but for me and other gentlemans are not. Please re-read all the @fleib posts where I agree with.

Vibrations or dead silent?, that's the question.

Regards and enjoy the music,
R.


"The motion of the pillar"......
There you go again. Nobody is claiming that a "moving pillar" is good but you have simply assumed that ALL pillars move because you yourself have used a 'moving' pillar (which you still refuse to disclose despite my three attempts to wrest it out of you).
A properly designed armpod sitting on a well isolated rigid base/shelf/plinth will NOT move despite your ill-informed protestations.
Look at it this way then: If the pillar is motionless, and the bearings of the platter are able to move (vibrate) you still have a problem- one that is solved by a plinth that rigidly couples the the pillar and the platter bearings.
Mathematically its an associative and commutative function.
Now this is illuminating and perhaps needs an explanation from you about what you believe could possibly be 'moving' in your 3/4" solid aluminium plinth?
In other words....what did the "brace" fix that was a weakness in the solid aluminium?
This is a structural and not a mechanical engineering question and requires a structural engineering answer...
I've already explained that- several times. Right now I think you've not read this thread through.
FWIW thekong's test above is really similar to one we performed several years ago.
Atmasphere, you talked about a motor producing 90 - 95dB of noise in the room and described the vibrations as room borne not air borne. This sounds more like a seismic event than music playing, as if a bus or truck drove down your street and shook the house. We not only have 90+dB of noise, we also have the motor vibrations which produced the noise.
 
@fleib, actually, no, I didn't mention anything about a motor!! I don't know how that got started- but it might be because people haven't been reading my posts and are just reacting.

Where the vibration comes from is airborne. I don't know about you, but I like to play my stereo in the same room as my turntable. Sometimes it gets loud, and the ability of the turntable to be impervious to airborne (or structural borne, as in bass that is transmitted though the floor) is really important to an uncolored presentation. 

I suspect it doesn't matter. This seems to be more than sound pressure waves hitting the table, and we might as well be talking about table mounting in general. Why is a plinth superior in maintaining identical movement between arm and platter? Either proximity, or lack of rigidity in table or pod coupling to the base.


I have mentioned why a plinth works better in prior posts. I am now certain that they are not being read- or intentionally misunderstood as a means of promoting an agenda. So to answer yet again, a plinth that rigidly couples the platter bearings to the base of the arm insures that both the arm and platter are moving in the same plane and at the same frequency, which prevents said vibration from being transcribed by the stylus, which otherwise it is free to do.

This is why an arm pillar will always be noisier and more colored no matter how dead it is. It can't possibly be in the same plane as the platter bearings, and if you think we are talking about absolutely microscopic issues you are absolutely correct! But think about the fact that you need a microscope to see what's going on in the grooves of an LP or to really view a stylus and then its blatantly obvious that the more rigidly you can couple the arm base and the platter bearings, the less there will be any minuscule motion between them.

Its not enough that you have the most dead pillar in the world. If the platter bearings are not in exactly the same locus 100% of the time then all the effort into that arm pod is nil. And that is the fact that shoots all arm pillars down. Essentially the base upon which they rest becomes the plinth, and its simply not going to be rigid enough!

No offense Ralph, but your expertise is with tubes and modifying an old Empire table does not qualify you as a table or arm designer.

If that were all there were to it I would agree 100%!! If you think though that working with an 'old Empire' is my only exposure to mechanical issues you would be mistaken. What you are engaging in here is a logical fallacy- without really knowing anything about me, you are trying to reach the argument that because the you only know me for award-winning electronics, that somehow I must not know anything about mechanical engineering. That's not a safe place to set your assumptions or anyone else's!

Trying to make this sort of appeal does not further the debate (although from my perspective I am not debating, instead simply explaining a rather basic engineering principle that relates to LP mastering and playback); all it does is exercise a logical fallacy, and by definition that means your conclusion is incorrect. I am currently under the assumption that you can do better than that- please don't prove me wrong.
Dear @atmasphere : According with my very high ignorance level there are some things that goes against your " scientific " test:

- as @halcro posted one of your premises is that exist movement in the stand alone pillar. Why don’t choose as premise that the pillar has no movement? what could happen at your scientific/theory?
Nothing at all. As stated previously, the stylus does not care where the difference is between the two- if the pillar is still and the platter bearings are not, its still a problem.

- I have a premise too in my subjective " science ": that the holding cartridge tonearm must be aisled from the self TT " movements/vibrations " and air borne effects in order that those non tonearm " movements " can affect/produce additional distortions/colorations to the cartridge performance.
Its best to isolate the motor such that its vibration is not a problem. Its also good to insure that the plinth is adequately damped. Beyond that I can’t comment on this passage as I can’t make out exactly what you are trying to say.

- according with your science my premise go against your theory because the tonearm has to vibrate exactly as the TT platter. So, if we have an integrated tonearm pod that does not vibrates at all then is wrong and add " colorations " by the cartridge.
Its not ’my science’, its just science. Please reread my posts above- clearly you don’t understand them else you would not have said this.

- according that we need that the integrated tonearm pod/base has those same platter bearing vibrations. So, a well damped/dead one integrated arm pod is wrong and is wrong because till today exist no TT dead silent beairng platter.

I’m not talking about how noisy the platter bearings might be. Nor am I talking about motor noise. Please reread my posts above as you don’t seem to have done so.

- So, I infere from your science that it’s better not to aisle/fuly damps the integarted arm pod. I don’t know what I’m missing here but I’m not convinced that is better if vibrates evenly with the platter that if that arm pod stays deadly.

The arm pod can be fully damped as long as it is ridgidly coupled to the mounting of the platter bearings. Please reread my posts above as you don’t seem to understand this rather basic engineering principle. Could you also explain the word ’aisle’ as it seems to be a mis-spelling or mis-use.

- other of my premises is that the cartridge must be " aisle " from vibrations as we can. Now, the ideal scenario for a cartridge ridding job is to make that job with no single vibrations, this is imposible to have/exist.
Ah- I think you mean ’isolated’ when you use the word "aisle".

If that is correct, the statement above is not entirely correct. It is true that it is good to isolate the turntable/pickup from vibration as best we can, but the cartridge must be held in firm locus at any time during its journey across the LP surface. If this simple issue is ignored, noise and coloration will result.


- starting from that ideal scenario next step could be to put at minimum all non-self vibraions that affect the cartridge job.
The bearing platter vibrations always affect the overall cartridge job as the tonearm/cartridge resonance frequency and the own tonearm additional vibrations and the feedback of all those vibrations and now we " need " that the integrated tonearm pod stays vibrating evenly with the bearing platter and this represent additional vibrations/colorations that are produced when in touch with all the other already generated vibrations because here exist a delay time on those same kind of vibrations and its amplitude are not exactly the same.
You don’t seem to understand that if the platter bearings are noisy, no amount of vibration isolation of the arm will prevent the cartridge from making that fact plainly obvious! I’ve serviced thousands of turntables in my life and seen that played out quite a lot. If you have a noisy platter bearing, you should replace it with a functioning unit.

My God !!!!!!

We need additional integrated arm pod vibrations. Why and external dead silent arm pod is different of a dead integrated arm pod?
Your conclusion here is not logical and runs counter to real life! Do you not understand how a cartridge transcribes vibrations into an electrical signal?


is it better/worst a dead silent arm pod integrated or not? or is better the one that vibrates evenly with the bearing TT platter with all those additional vibrations I talked about??

If the base of the arm moves in unison with the base of the platter bearings, the noise of the platter bearings will be much harder for the cartridge to pick up. If the same factor is on both sides of the equation, it can be canceled.

For you and the other advocates to integarted arm pod things are so " easy " but for me and other gentlemans are not. Please re-read all the @fleib posts where I agree with.

Vibrations or dead silent?, that’s the question.

Regards and enjoy the music,
R.

I think the problem you are struggling with is the idea that somehow you are going to make everything perfectly dead silent.

In the real world this is impossible. No matter how dead you make it, there will always be some difference that you can’t find or fix. That difference will be interpreted by the cartridge as noise or a coloration.

Because of that in the real world a good solid plinth will beat a separate arm pod/pillar every time. Again, this is not to say that a pillar can’t give good performance, it is saying that a silent and rigidly coupled plinth will give better performance. You can’t beat the math on this one.

BTW, what I have stated above is also why an arm board on an otherwise solid plinth may not be a good idea. This is because if the arm board is of a different material as the plinth, it will be able to move due to vibration in a different plane. This is why we don’t have an arm board on our turntable.

Now if you have been thinking of a poorly designed plinth and comparing that to a separate pillar, then you are not thinking about what I am talking about at all. This is so important I’m going to repeat it:

If you have been thinking of a poorly designed plinth and comparing that to a separate pillar, then you are not thinking about what I am talking about at all.
Ivor Tiefenbrum raised the question of the importance of the integrity of the mechanical relationship between arm and platter almost fifty years ago. And his Linn Sondek turntable proved that integrity to be the number one priority---number one---in the design of a table. Nothing in the universe has changed since the early 70's---this is settled law. I wouldn't even consider a table not having a platter bearing and arm pillar sharing a common plinth. Seems like nothing more than obvious common sense to me. You don't have to be a mechanical engineer to see the wisdom of the concept.
Fleib

bdp24,

A table with a suspension is a different story.


and whether that table (suspended or not), is on a

1) suspended floor itself
2) concrete poured basement floor
3) a load bearing TT wall shelf
4) other

is the bigger story. just sayin.

All poster opinions on these forums should qualify this.
All my opinions are based on a concrete poured floor - not suspended.
I have done the work in my basement to find the air pockets. Another discussion

Atmasphere,

From your post near the bottom of page 1:

**As to sound pressure- we get about 90-95db of noise going on when mastering. The vacuum system is enclosed in its own chamber, but still makes noise when in operation.**

Unless that means something other than what it says, you're changing your story.

I understand your engineering principle, but I question the significance.  Will a massive plinth transmit small main bearing movement to the arm base?  Excite a tuning fork and touch it to a big rock and the vibration is turned to heat. Even if it does transmit it, the resultant arm movement will occur after the main bearing event. 

What about micro movements you allude to? Not likely, and with the same time consideration.

Sound pressure waves hitting the platter are also hitting the plinth and arm at virtually the same time. To say that a plinth will insure coincidental movement between cartridge and record also doesn't make sense with regard to time. The impact on the record player is instantaneous and rotation of the record is continuous.

Regards,

Dear Fleib, I cannot resist commenting on your penultimate post, dated 05/05 at 8:51 PM.  A suspended plinth is not a "different story"; it is the same story, except in the case of a suspended plinth vs a stationary discrete arm pod, it is plain for you and me to see WHY the discrete arm pod is not a good idea.  To wit, there would be a great deal of movement of the LP surface, mediated by the suspension, that could not be followed by movement of the tonearm pivot, and this would generate spurious signals at the cartridge/LP interface. On a more micro level, this principle is operative in the relationship between any plinth, suspended or not, and any arm mounting system.

Lew, That's BS for reasons already stated. Micro vibrations wouldn't make it from record or main bearing to the arm, with a massive plinth. With a flimsier plinth the movement of platter and arm must coincide perfectly for this principle to be valid, and that is not the case when vibrations originating from the platter are transmitted through the bearing, then the plinth and to the arm base.  Surely you jest.

Regards,

A table with a suspension is a different story.

A suspension is irrelevant. The rigidity of the plinth is what is important. 


Unless that means something other than what it says, you're changing your story.

My 'story' has been 100% consistent through this debacle. However I suspect that my prior posts have not been read very well, or they have been interpreted in some way I could not predict.

To be clear here, the noise in our mastering environment is airborne. The vacuum system sits in a box (to suppress noise) at the other end of a rather long hose.

I understand your engineering principle, but I question the significance. Will a massive plinth transmit small main bearing movement to the arm base? Excite a tuning fork and touch it to a big rock and the vibration is turned to heat. Even if it does transmit it, the resultant arm movement will occur after the main bearing event.

You say you understand this basic engineering principle (not mine by any means BTW), but the rest of the paragraphs contradicts that statement. So I think that the first statement must be false.

FWIW, I think we can be unconcerned about the bearing noise in this conversation (although I do think its important), unless the bearing chosen has serious problems! Even the bearing system employed on a lowly 1970s BSR is relatively quiet and not a source of trouble unless it is damaged or in need of maintenance. Modern turntable bearings are usually pretty good (although I have seen some wankers in some +$20K machines, worse than those BSR bearings I just mentioned but likely that is a topic for another thread). So the real issue is airborne and structural borne vibration, which I have maintained since the inception of this thread. If you don't get that, then you've not been actually reading my posts. 

What about micro movements you allude to? Not likely, and with the same time consideration.

Sound pressure waves hitting the platter are also hitting the plinth and arm at virtually the same time. To say that a plinth will insure coincidental movement between cartridge and record also doesn't make sense with regard to time. The impact on the record player is instantaneous and rotation of the record is continuous.

If you don't understand the bit about micro movements here, then my supposition that you don't understand the basic engineering principle is confirmed. You might want to have a conversation with a mechanical engineer whilst maintaining an open mind.

If you look at your second paragraph here, obviously you understand the problem, and then like Raul did a few posts above (see 'My God!') arrive at a false conclusion not supported by logic. I find it perplexing- so I have to assume that an agenda is underlying this that causes you to veer away from what seems a rather obvious solution. BTW, the fact of the platter rotating has nothing to do with this! Again, we discovered the problem and made measurements that confirmed it; it seems that those that are proponents of arm pillars have no measurements whatsoever.


Flieb, Exactly what part of what I wrote, specifically, is BS?  Would you use an outboard arm pod with a suspended turntable? I don't think so. You are arguing specifics (it might not work well because of this or that), and I am talking about the ideal goal.  As I also said somewhere further up the thread, the engineering problem is to make the tonearm/platter behave together.  I never said that was easy to do, but that should be the goal.  If you mount the tonearm on a separate structure, then you have abandoned hope of achieving that goal, or at the very least, you've made it more difficult than it needs to be.  Certainly, there are subpar executions of the integrated turntable/tonearm paradigm; that's one reason why turntables sound different from one another.
I propose that Ralph be enrolled on the calendar of saints. His restraint is supernatural - a miracle thrice renewed!!

I propose that Ralph be enrolled on the calendar of saints. His restraint is supernatural - a miracle thrice renewed!!
Yes indeed...because Ralph can, with the same conviction that he demonstrates his turntable theories....can postulate that OTL valve amplification is the only true path to audio Nirvana....despite the observable distortions.
And pray tell us terry9......do you run your amplification using OTL devices?

**As to sound pressure- we get about 90-95db of noise going on when mastering. The vacuum system is enclosed in its own chamber, but still makes noise when in operation.**

That's a direct quote. Now we learn the motor is at the end of a long hose. Does it produce 90-95dB of noise in room?  If so, is this noise + mechanical vibrations? 

The measurements are based on this story and now it looks inappropriate. This is the same as the music coming off a turntable?

Looks like we have no relevant measurements.

fleib

True, a suspended-subchassis table will always have a plinth common to the platter bearing and arm pillar (at least as far as I know!), while a non-suspended doesn't have to, the later fact the impetus for this discussion. When I was said I would not consider a table without a common plinth, that included non-suspended tables, which I agree with the others is, in regards to the importance of the mechanical integrity between platter bearing and arm, no different than a suspended-subchassis design. How that plinth is isolated from what is below it (by springs---commonly---in suspended tables, and whatever method in non-suspended) is a related but separate issue. But the "correctness" and superiority of a common plinth turntable design does presume the plinth provides an inherently rigid mechanical connection between platter bearing and arm pillar simply by virtue of it being common, too large a presumption as well as an over-simplification, I realize in hindsight. The rigidity of the plinth in different tables varies, and is a major contributor to the sound of every table. Their designers have invested a lot of time, effort, and money into either maximizing the rigidity of the plinth, or at least strengthening the mechanical connection between platter bearing and arm pillar.

My table was designed with this matter a very high priority, it's non-suspended plinth made of steel in the shape of a shallow upside-down baking pan, and filled with plaster of Paris, to make it much stiffer and more non-resonant than the common MDF, acrylic, or aluminum (or combination of two or all three materials) plinth. Recognize it? But the designer of this table took his intention and dedication to making the mechanical nature of his deck as stiff as possible to another level by addressing the other area of mechanical integrity in turntable/arm/pickup design, the front end of the arm. Free to vibrate (how much and at what frequencies dependent on the stiffness and resonant characteristics of the headshell, arm tube, all the way back to the arm's bearings and counterweight, and down into the main pillar), it will and does! When the end of the arm, and therefore the cartridge, the measuring device of the LP groove, is free to vibrate and resonate (especially cartridges employing low-compliance stylus'), it is surely adding to or subtracting from the output of the cartridge. That is a major source of lost or added information in the playing of an LP, and only one table in the world addresses the issue. Now do you recognize the table?! ;-)

Lew,

**To wit, there would be a great deal of movement of the LP surface, mediated by the suspension, that could not be followed by movement of the tonearm pivot, and this would generate spurious signals at the cartridge/LP interface. On a more micro level, this principle is operative in the relationship between any plinth, suspended or not, and any arm mounting system.**

Not true. On a micro level the vibrations would not make it between platter and arm with a high mass "dead" plinth. Part of the reason such plinths sound good is because they resist vibration transmission.

You think this engineering principle holds true under any circumstance. It does not. It holds true if and only if part of the table is in extraneous motion and the other parts move with it simultaneously. That is motion other than normal platter rotation. High mass tables are more likely to be immune to such motion.

**Reed used to make an armpod.
 
I believe Nandric (Nikola) had the first one ever made by Vidmantas. I was looking for the resonance research data that was prominently displayed on his website, which showed a visual of the different resonances and their paths (integrated versus isolated parts). The info had a lot of cool lines and colors differentiating the two, with information clearly supporting the armpod.**

Regards, 



The platter and arm must move in the same plane and frequency, should there be any movement at all. Likely this would be airborne induced.
That is the most unlikely scenario. Airborne induced vibrations in the platter/tonearm/cartridge synergy are virtually non-existent as the turntable world would have ceased to exist if this were not so.
Err...anyone ever go to clubs with DJs playing vinyl at 105dB levels?
Structure-borne vibrations are by far the greatest source of distortions in the vinyl playback system. That is why the makers of anti-vibration stands (both active and passive) are successful. These stands have zero effect on air-borne vibrations.
Because the induced ’feedback’ is amplified when the volume is increased....most lay people conclude that the ’volume’ has caused the feedback when it is in fact the ’volume’ that simply amplifies the structure-borne feedback which already exists within the particular system.
Yes indeed...because Ralph can, with the same conviction that he demonstrates his turntable theories....can postulate that OTL valve amplification is the only true path to audio Nirvana....despite the observable distortions.
For the record, this is not entirely true. I do think OTLs have advantages, else I would not be making them. But all amplification has observable and audible distortions. A topic for another thread.

That’s a direct quote. Now we learn the motor is at the end of a long hose. Does it produce 90-95dB of noise in room? If so, is this noise + mechanical vibrations?

The measurements are based on this story and now it looks inappropriate. This is the same as the music coming off a turntable?

Looks like we have no relevant measurements.

The vacuum system, along with the monitors, produced about that much sound pressure at the time. There is no mechanical vibration from the vacuum system whatsoever- all the sound is airborne. So these measurements are quite relevant. Fleib, if I can offer a bit of advice, try to craft your posts in a way that it is not obvious that you are simply trying to make the other party wrong by ignoring facts. You will have greater success.
But the "correctness" and superiority of a common plinth turntable design does presume the plinth provides an inherently rigid mechanical connection between platter bearing and arm pillar simply by virtue of it being common, too large a presumption as well as an over-simplification, I realize in hindsight. The rigidity of the plinth in different tables varies, and is a major contributor to the sound of every table. Their designers have invested a lot of time, effort, and money into either maximizing the rigidity of the plinth, or at least strengthening the mechanical connection between platter bearing and arm pillar.
As I have maintained since the inception of this thread, the rigidity of the plinth is paramount. If the plinth is not rigid, then it can talk back to the pickup and editorialize. This is no better than an arm mounted on a separate pillar.

I think we can all agree that none of us are interested in what sucks. We want the best for our ears. So can we agree that in this conversation we are talking about the assault on the state of the art? If not, the conversation is moot. Please do not bring up inferior execution as an argument- such would be a logical fallacy known as a Strawman.
the front end of the arm. Free to vibrate (how much and at what frequencies dependent on the stiffness and resonant characteristics of the headshell, arm tube, all the way back to the arm’s bearings and counterweight, and down into the main pillar), it will and does! When the end of the arm, and therefore the cartridge, the measuring device of the LP groove, is free to vibrate and resonate (especially cartridges employing low-compliance stylus’), it is surely adding to or subtracting from the output of the cartridge. That is a major source of lost or added information in the playing of an LP, and only one table in the world addresses the issue. Now do you recognize the table?! ;-)
I don’t recognize the machine, but I recognize the flaw in the thinking of it in that way as you point out. The cartridge must be held in absolute locus- the arm can’t be talking back to it any more than the rest of the machine.
That is the most unlikely scenario. Airborne induced vibrations in the platter/tonearm/cartridge synergy are virtually non-existent as the turntable world would have ceased to exist if this were not so.

This statement is false, although I do agree that structural borne vibration is also a problem and have stated exactly that in prior posts. This comment suggests to me that you have not read them.

If you think air borne vibration is not a problem you are up against the issue of the real world. No matter how dead you think a thing might be, it will always have some motion, some vibration. Its inescapable, unless you subscribe to the idea that perfection is indeed possible in this world. When I went to engineering school and for that matter elementary school, my teachers were at pains to make the point that perfection is impossible - that is why we have the term ’state of the art’. It is this latter bit that underscores how your statement in quotes can’t possibly be true.

So a proper design must take into account that air borne vibration as well as structural borne vibration exist no matter how damped the setup.



**Fleib, if I can offer a bit of advice, try to craft your posts in a way that it is not obvious that you are simply trying to make the other party wrong by ignoring facts. You will have greater success.**

My posts were based on the information you supplied or didn't. How can I ignore facts which weren't offered?  You were repeatedly asked details about the pod. Did you give them?

Assuming your results are what you say, why should we accept this as the last word on this matter?  Prominent table/arm designers have reached different conclusions.  You're more knowledgeable than Kuzma, Reed, or Torqueo Audio?

Reed site had a set of resonance numbers which favored the pod. They're gone now, but your anecdotes are fact?

Atmasphere, you've made your point and I think everyone understands it. Why don't you go back to tube design or mastering? Unless we can figure out why results differ, there's nothing more to say.


My posts were based on the information you supplied or didn't. How can I ignore facts which weren't offered?

Trying to make someone wrong is a simple technique, which weve seen on the web countless times. In so doing, the goal is not mutual understanding but simply trying to make someone else wrong solely for the sake of doing so. It does not further knowledge. IOW I don't agree that your posts were based on what you say- as far as I can see, you want me to be wrong and go away, simply so you can be right.

I'm not here to make you wrong; someone asked a real question and I answered it with the accepted and correct engineering principle. It does not matter to me beyond that, others might disagree, but they are not wrong because **I** don't agree with them, they are wrong because they lack the engineering understanding:

Assuming your results are what you say, why should we accept this as the last word on this matter? Prominent table/arm designers have reached different conclusions. You're more knowledgeable than Kuzma, Reed, or Torqueo Audio?

Reed site had a set of resonance numbers which favored the pod. They're gone now, but your anecdotes are fact?


To the latter: of course, but to be clear they are not anecdotal if backed up with the measurements; of which so far I seem to be the only one here to have caused their hand to move to get (and I hope the irony of this conversation is not lost on anyone....).

To the former: apparently, if you are saying by being correct on this subject I'm more knowledgeable, but I'm not under the illusion that because I am correct about  this that I know more than someone else. What's happening is I understand the engineering, that's all.

I've been designing tube stuff and mastering all along- no need to go back, I'm already there. I know why the 'results differ'.

It does seem though that this rather odious bubble has been popped and its contents safely dispersed without harm to the parties in the vicinity.

No strawman argument from me Ralph, at least not intentionally. I’m with ya, man! But in the different executions of a solid plinth offered by a multitude of turntable makers, all attempting to advance, or at least equal, the State Of The Art, there are varying degrees of success at achieving mechanical rigidity. I was merely acknowledging that reality.

The table I was referring to, by the way, is the Townshend Rock, the only table that locks the front end of the very long and flexible (in relation to the size of the LP groove) pickup arm onto the plinth, much as the back end is on all good tables. And that means every arm, no matter the design and quality. Makes other table designs look downright sloppy!

Halcro, you ask if I run OTL. Well, I did, and they sounded fine, but I decided on home brew, where cost is less of an object. Before building anything, I decided to optimize the system (instead of the pieces thereof), and found that I could improve system performance by using solid state Class A, push-pull, with low voltage rails, which allowed me to safely remove the now-redundant protection circuits from the ESL's.

Amps better than OTL? Don't know - but the system sure is.



Post removed 
If you think air borne vibration is not a problem you are up against the issue of the real world. No matter how dead you think a thing might be, it will always have some motion, some vibration.
This is an uneducated assumption.
Most people follow this belief but if you had studied acoustics and the science of materials, you would know that materials react to air-borne sound by a mixture of:-
  • Reflection
  • Absorption (as heat)
  • Transmission (passing directly through)
It is only when sound pressure of a sufficient volume (and that's important) at a material's Resonant Frequency occurs...that the material can 'vibrate'.
You do know of course that the Resonant Frequency of most tonearm/cartridge combinations is 6-15 Hz and this is well below the frequency reproduction ability of all commercial loudspeakers and almost all subwoofers as well?
It in only in this frequency band that any vibration of the tonearm/cartridge can be observed. There is no 'alternate' vibration phenomena unless you can direct us to the relevant scientific papers?
For the heavier plinth and platter components of the turntable system, a resonant frequency in the order of 2-6 Hz may apply.
You seem to use the term 'vibrate' as if somehow it were a different genus to 'resonate'?
Not only is your understanding of air-borne sound transmission and vibration factually inaccurate, it is logically impossible.
Were it true....every increase in the volume dial would degrade the sound.
Let me repeat that....
If air-borne sound pressure is a problem in the turntable playback system, then every increase in volume would of necessity degrade the sound.
Now there are many out there who will exclaim that this is indeed the case with their systems but as I explained previously...they are hearing the effects of structure-borne feedback...AMPLIFIED.
There are tens of millions of turntable systems where turning up the volume is heard to IMPROVE the sound quality noticeably.


Halcro


"It is only when sound pressure of a sufficient volume (and that's important) at a material's Resonant Frequency occurs...that the material can 'vibrate'."

I want to be sure that I have interpreted your statement here accurately.

What you are saying is this....A material will NOT vibrate as a result of acoustical excitation unless that acoustical excitation is at the resonant frequency of the material and that this acoustical excitation is of sufficient energy.

Is this a correct summation of what you just posted?

Cheers.