Tonearm mount on the plinth or on Pillar ?

Hi Pani
It’s important imo, to remember that the plinth is the lowest member of a base. When setup in this fashion the shelf holding "all the goods" becomes the plinth.
I went down this road many years ago, putting a tonearm on an isolated armpod/pillar. I was curious, it was fun, and it involved a lot of learning. I took the idea further using symposium roller block jrs., and a VPI JMW 12 tonearm. The original idea came from a Greek audiophile. I had so much fun I wrote a review of it, with a short youtube.

https://www.youtube.com/watch?v=HSZSzxnN1mg

Going by memory I can tell you that the cartridge used was very high compliance, Dynamic Compliance: 50 x 10-6cm/Dyne and when set up in the traditional way sounded terrible on this tonearm. But when set up like this; well you listen.

Pryso
Plus I live on the West Coast where we are subject to earthquakes, some of which go unfelt. I don’t want my tonearm "dancing" around somewhere close to the correct position.

Pryso
I am thinking the symposium setup might actually work for an earthquake, but I have no experience. I have experienced only a couple of shakes in Ontario, barely noticeable . What do you think ?


Chayro - I thought that was an interesting analogy. Some have tried to use the analogy of two boats floating next to one another. This analogy doesn’t work for me. An analogy that works better - I put in a heavy 20 foot long dock in the water one summer, and was so happy with the accomplishment I danced on the end of it. It barely moved.

pani
In a typical cutting lathe is the cutting arm mounted on the same plinth as the platter or is it on a platform ?

here is a pic
http://www.sonicscoop.com/site/wp-content/uploads/2013/04/stocklathe.jpg

Pani
fwiw. I still do own three tables but only use one. Two of the three tables Verdier La Platine (main) and my DIY SP10 MKII (up to version 8?) from years ago have pillars/pods for the tonearm which is bolted into the plinth. The Platter structure is bolted into this same plinth. The Brass Pod on my SP10MKII is very heavy its not going anywhere but it was very easy to shoot a bolt in from the bottom, and I use only one tonearm with it so I bolted it in.

https://goo.gl/photos/1tpMKeEahAdXFEN38

The third table is a Jean Nantais table. I don’t know how familiar you are with his designs.

http://www.idler-wheel-drive.com/

Going back if I recall, Jean is very much in favor of a very rigid coupling. But even he recognizes the problems with bolting a tonearm to a plinth that is shared with a spinning platter/bearing/motor. All his designs have "voids" where the tonearm is mounted to lessen the effect of the plinth itself. This void extends down through the whole 100 lb plinth on mine. I think the plinth would weigh quite a bit more if the two voids for two tonearms were filled in.

Raul - you misunderstood the intent/purpose of the youtube video that my 16 year old son budding audiophile at the time took. He is now 21 - where does time go? This was an experiment/ a test during an Audiophile Phase. I indicated that this tonearm/cart/ in the traditional setup the sound was terrible; but the armpod setup with the roller block jrs. significantly changed resonances/vibrations (which vinyl play is all about) for the better.
The focus was the symposium roller block jrs. on an armpod; and the technics table has only a skeleton plinth. Not sure how you came up with a stock plinth ?

Pryso - I think at this point I am willing to put up with some earthquake shakes if it meant good year round weather. Can you imagine that armpod on the roller block jrs. if not being used moving back and forth, during a quake - like the buildings themselves.

moonglum

great vid. It could be planted on many audiophile forum threads. :^)
I use oil in the bolt threads of the pods before the bolt is inserted.

Cheers

@Atmasphere 

What is the vertical angle being cut into the disc where you work ?

thanks  

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.

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 ................ :^)

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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

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

Fixed Pillars/Armpods with a Suspended table ?

Lewm

Would you use an outboard arm pod with a suspended turntable? I don't think so.

Bdp24

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.

I agree with both Lewm and Bdp24.   

So then, is this setup some type of Optical illusion ?


http://www.whatsbestforum.com/attachment.php?attachmentid=19961&d=1429540940


The turntable appears to be stock to me.   The Armpod has been carved to fit around the plinth. The outboard Pillar/Armpod is an accessory product made by Acoustical Systems.

Now Henry says -

Dietrich knows a thing or two about turntables, arms and cartridges.

So Henry, any idea why Dietrich has put what looks like a fixed pillar/armpod on this customers suspended turntable ?  

Halcro
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.

I am very disappointed that you did not tell Ralph to yell at his cartridge. 

just sayin....

Lewm
Verdier photo: It looks to me like Dietrich simply replaced the OEM flimsy tonearm mount (an inverted L-shaped affair that never looked to be very stable, to me) with a nice solid pillar and then attached it directly to the granite "plinth". Nothing really radical but certainly better than stock.

Optical illusion Lewm.

(an inverted L-shaped affair that never looked to be very stable, to me)

An Aluminum block rigidly mounted to its plinth .....unstable ? ok......

Look again. the turntable has been rotated counter clockwise. 90 degrees. The stock pillar is still there holding up the other tonearm. The external pod is not touching the same plinth that the platter is attached to.

Nothing really radical but certainly better than stock.

Well ok if you think so. But "Earth" for both of them, Tonearm Pillar and Plinth that holds the Platter, is now the Vibraplane.

I think you just jumped over to the other side and became one of them Copernicans with your comment ?

Excellent comments Pani :^)

Pani
I have owned the Verdier too and have tried various setup configurations.

This may give the sound some added transparency due to the seperation but they dont sing like one. The coherency is affected, I have tried it first hand.

Did I read on here in the past that you owned a Nouvelle Verdier ?

IMO/IME it’s very easy to fall into the trap of listening to "sounds" (Audiophile), rather than the flow of the music created by the musicians (Music Lover). I have been in these phases. fwiw - they (phases), imo can be very therapeutic especially during difficult times. But it becomes about the gear, and not the music anymore.

Now that linked table is a naked design; meaning all parts easily accessible. To the "ever wanting change" vinyl audiophile - it is crack. I resisted change with it, and spent time on setup with dialogue from its maker-designer. May he rest in piece.

Pani - I think your personal experience answers the question in your original post quite well ?

Cheers