A Copernican View of the Turntable System

Thx for the responses - I use three as well - spiked mapleshade spikes and am very happy with them. Will look out for the 616's to try out when they come up for sale.

One of the senior members in the other forum I am part of said something about isolated arm pods in a way that I think “nailed it” as far as what I am hearing.

"These are said to break the rumble feedback loop through the plinth as it contacts the arm at both ends - through the arm pillar and cartridge via the platter".

That’s it for the theory part.

Dear Lewn:

I thought in the other thread that you were going to attempt this with your Denon. I was really looking forward to your impressions based on your vast experience.

Your comment:
“Apparently the no-plinthers have observed that Newton's Third Law is not much of a problem in this regard”.

Btw - Thinking of having T-shirts made up that say NO-PLINTHER – just kidding. Just remember I still have another TT with a plinth that I enjoy.

Anyway to answer the question - When I start my sp10 there is a slight split second vibration that can be felt in the motor casing. After that it might as well be dead – can’t hear or feel anything and it hasn’t moved at all since it was last set up.

All

I have to admit I am a little dumbfounded at some of this. Vector diagrams?

If trying a separate arm pod and no plinth “around -holding ” the TT meant lots of investment in time and $$ - I would understand the reluctance– but its been discussed many times by Raul and Halcro - all you have to do is take the motor/platter unit out of its plinth, put it on some type of legs and construct some type of temporary arm out of some cheap material to hear the difference.

My first attempt was an arm pod made from glued MDF layers! I believe Halcro used a can of some vegetable!

What I am trying to say is from my experience you will know right away whether you like what you hear or not - It is that evident. Then you will know whether you want to pursue this further. Having a hard time understanding the reluctance to try it ? Are you concerned you might like the sound?

Not sure if everyone feels this way - but - To me in this hobby nothing is more satisfying than when you come upon something - a component, a process, some setup change - whatever - that makes such a big difference to your system – that it is almost like a revelation to your listening. I have spent days moving speakers around. My floor looks like a police scene with the tape markings. This experiment took the weight of that plinth off my shoulders. It now sits in another room and my wife is asking me what is going on since I disappeared for weeks when I was involved with it. I am wondering too.

I find it ironic that most of these moments for me did not equate to a lot of money having to be spent.
How many have re-positioned speakers after having them in the same place for years. It was enlightning. This might be like that.

I don’t see the need for a debate or dispute here at all – if you are passionate enough to discuss it you should try it.

Cheers Chris

Dear Lewn - you wrote

"I have involuntarily been dreaming up a way to make a really heavy one using a cylinder made of bronze that can be purchased direct from a metals company here in the US, in a wide range of diameters and almost any reasonable height. The mind cannot rest".

www.metalsupermarkets.com

And reasonable cost too. They make it real easy for you by cutting on the spot.

I have a picture of one of their shelves in my gallery link that I posted earlier. Here it is again.

http://www.canuckaudiomart.com/view_userimages.php?user_id=5181&image_id=39023

Lewn - I bet you will continue to be tormented by these visions until you try it out - :).

As an update I have been contacted privately by two individuals who are trying this out. Plinthless and separate armpod. I have encouraged them to post but they choose not to - at least not here. One of them uses a panzer plinth with his SP10 and also has a Raven.

Looking forward to hearing from them during the winter and I hope they decide to post their impressions here if they read this.

Cheers Chris

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 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 ?

"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.

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

Hi Henry- you stated and I agree with this concept based on what I am hearing so far.
"I believe both turntable and arm pods should be 'coupled' in the same way ie all spikes.
I don't believe you should have spikes on the arm pods and pliable footers on the turntable OR vice versa."

Both my sp10 and ET armboard are on spikes. However.

I am also thinking if you are able to isolate the Platter/motor and armboard "properly" then this should not matter "as much" ?
If someones specific combination works in their system/kit it should be evident in what you hear - which is what matters not the concept.

This project has provided me with very neutral,distortion free sound - meaning to me no pronounced highs or lows, followed by what I have found to be a very strong desire to... and be able to - turn up the db as Dgob stated in an earlier post and enjoy the music immensely. Isn't this last sentence the PROOF "for me anyway" if certain projects are heading oneself closer toward "shangri la" in this hobby ?

My listening since implementation has been at a higher db. I'd like to go higher still but my family doesnt allow it. I need to spend more $$ first isolating my sound rooom better :).

Curiosity killed the cat - I put a wanted ad out for those AT616's and someone from Denmark replied and well I now have a set coming to me to try out this theory different feet on TT and armpod/board. I want to hear how it changes things up. Will let u know.

Hi Dgob

How heavy is the Acoustic Signature arm board that you are using and I am curious what type of center clamp you are using on your sp10 ?

My ET 2.5 armboard weighs more than the sp10 itself.

The next one will be made of brass and I will ensure it weighs more still. I feel the weight on the spikes is critical for isolation.

Dear Thuchan - thank you very much for your cartridge recommendations for my ET 2.5 arm.

Cheers Chris

@Chris: how did you put spikes beneath your sp10? I'm assuming there's a board in between? That is, the TT sits on the board and the board is on spikes? Or did you thread spikes directly beneath the chassis?

Hi Banquo - Each of the mapleshade footers have a dimple on top. I am using the bottom half of a two piece system. I put a dab of blue tac on the dimple.

The blue tac after setting in overnight is not going anywhere. For me to remove the footers now requires considerable force. You have to pry them off. So no threading was required.

I have a picture of the mapleshade footers in this link.

http://www.canuckaudiomart.com/view_userimages.php?user_id=5181&image_id=40437

Putting another board between the sp10 defeats the purpose of this to me. It adds one more layer and one more chance of introducing resonance going up to the platter and down.

My armboard although not pretty to look at is very functional and will not move. It also holds the bracket that the tonearm cables are connected to.

My apologies Banquo.

Actually I sort of understand how you feel as I travel between two properties weekly these days and only have vinyl set up at one. My TNT is too cumbersome to move there.

Considering the material needed for an armpod can be picked up, cut and ready to go by evening I am seriously considering another DD unit to set up plintless there with armpod.

Dear Dgob - congratulations - isn't it a grand feeling getting closer to the music and the family at the same time.

Is the feeling a little more special this time around because this upgrade cost practically nothing ?

Dear T-Bone you said - b) taking out the symposium (two isolation methods next to each other is usually worse than just one in my experience) - both of which should have improved things.

I believe my set up supports this as well – my sp10 is on 4 inches of maple which itself sits on the spiked columns of the actual stand – not another shelf.
Cheers Chris

Very nice review Dgob – kinda makes use wish you had your sp10 back Banquo ?

I have been using the AT-616’s for a couple of weeks. I was able to make my ET 2.5 arm fit by raising it to its highest point and using higher spikes.

http://www.canuckaudiomart.com/view_userimages.php?user_id=5181&image_id=41263

The 616’s adjustability makes leveling of the sp10 platter very easy. For those familiar with the ET 2.5 ensuring the air bearing arm is level is even easier – laser guided or regular level not required.

I still believe the key to the improvement was and this is gut feel only 75% isolated armboard and 25% getting the sp10 out of its plinth. Isolating and mass loading the armboard I feel was key.

Dear Dgob – you listened to your setup with the armboard attached to the naked sp10 first – it improved the sound sure – but wasn’t the bigger jump in quality getting the armboard isolated and mass loaded ?

Any thoughts on this.

Cheers Chris

Dear Lewn you wrote.
“BUT, what tonearms are you guys using? Given the rather large square "skirt" that surrounds the platter of the SP10 and the space needed for an outboard arm pod, it would seem to me that this can only be done with tonearms that are at least 10-inchers and longer, pivot to stylus. Yes?”

I would think anyone pursuing this wants the advantage of using any arm they want. My VPI pivot arm is 12” so I can’t verify this but considering there is no real estate constraint here other than your actual platform, your armpod need only be big enough to accept the bolts that the tonearm attaches to and you can place it anywhere on your platform that it lines up. Maybe Raul, Dgob, or Banquo can verify the 9” tonearm ?

I realize there are some on this thread that do not support the ET and/or linear air line bearing arms in general so I am saying this for those reading with ET’s as there are quite a number of us out there.

This combo sp10 / ET arm is a natural fit as both have straight edges. Alignment could not be any easier. The ET’s multi adjustments allow it to be mounted on whichever side of the sp10 you may want it on. If you look at my link in the previous post you will see it was on the other side when I used a plinth. The space between the sp10 and ET arm collar is 2 credit cards.

Dear Nandric – that Kuzma XL air line tonearm you mention sure reminds me of another tonearm?

Dear Dgob – I agree with what Rail said about using the 616’s for an arm pod – they squish when pressed much like the feet of my VPI TNT table. I would have tried it anyway if I could to hear regardless – there are no rules of engagment here – but my armboard is 12 inches long and 4 inches wide on 3 spikes. Note the ET arm will fit easily on a heavy brass 3 inch or bigger round armpod.

FWIW - AT616 versus my previous setup Mapleshade Spikes - too close to tell really – but the 616’s are adjustable so there - I believe any real $$ should go into a better armpod anyway – supporting the theory 75% armpod 25% plinthless DD TT as the reason for the sound improvement.

Cheers Chris

Good info Lewn - I dont have a 9" arm. A dis-advantage of the ET arm is it sits too close to the platter and does not allow for a ring - if u wanted to experiment.

Ebm – if interested email me

I will let you know the steps to produce a basic arm pod / board for your setup.

Dear Thuchan

I selfishly meant your Eminent Technology arm.

But any other surface mount tonearm would make this very simple and quick to try out.

Chris

ArmPod Instructions - 1,2,3

This is for those that have been reading this thread, are interested in trying this out, but may need some help with it.
I have put together a short document to help with it. You are welcome to it - just send me an email and I will forward you a copy.
It covers.

1) How tall does the armpod need to be.
2) What shape do you want your Arm Pod to be ?
3) Acquiring materials
4) Tools for Holes
5) Drilling Holes on Metal
6) Assembling the ARMPOD

Thx for the pre-edits and feedback Banquo.

This project rates a 3 / 10 difficulty - about the same as assembling IKEA furniture, will cost you $100 and can get completed in a weekend. You can even get someone else to do the drilling of holes for you. I bet you will be so happy with it (sonically) that you may not even want a more expensive one unless you need some eye candy.

I was going to put some bullets into a post here but quickly realized that wasn't going to cut it.

Cheers Chris

Dear Geoch - regarding your comment on the armboard. This thread has really nothing to do with our knowledge on this or that - the thread is about people in this hobby trying something and letting their ears decide if it sounds good to them.

To them it has provided priceless passion and satisfaction.

Do you not trust your ears ? For amount of effort and time this takes to setup your response is well "just watching your findings " ?

All high end manufacturers use this concept.

Dear Geoch
No offence taken.
Life is short and this hobby is one of the avenues that has allowed me get into the right frame of mind to help deal with my real family and work challenges. We have all probably done what others would call "extreme things" in our hobby. I have a problem with speakers. 7 pairs in 3 systems and I just brought home Wayne PK Quad 57's to try out.

Those of us using this approach will not be offended if you try it and do not like it in your set up. We are content. Unless you can suggest a better way and we will be all over it. I know I would be.

When you go to some of these web sites and see what just a couple of manufacturers charge for these isolated armpods. They are thousands of dollars with no cartridge.

Dear Nandric - I agree with you - my statement should have been clearer and implied "the end cost to us" when we finally get the product. I realize in a small market like this it must be very difficult for the manufacturers.

During my project keeping it simple was the objective and not having to get machinists or other people involved. It was a DIY project to see if I liked the sound. My next step would have been to make a nicer arm pod with the help of a machinist and other folks. It sounds so good to me however that this will not be necessary. This approach allowed me to get intimately involved with the materials and setup.

As the guide says - the key is getting your tonearm base on the plate. What do your tonearms arms sit on now? Are they attached directly to the plinth or on a separate plate that attaches to the plinth. For me I had hardwoods that I had already experimented with when I used a plinth. Common options are maple, oak, birch, acrylic, but even panzerholtz or metal can be considered. I went to home depot and picked up 3 and 4 inch wide solid pieces of wood in varying thicknesses and cut the length from it required for my tonearm. The entire lenghths of the wood themselves were about $8.00.

Both the tonearm bases for my ET and VPI JMW 12" arm are shaped like a closed letter U so a rectangular piece of wood worked well.

As per the instructions in the guide I left extra wood on each side for two machine bolts - this is how the tonearm plate attaches to the actual armpod. Then the shape of the armpod becomes your choice as long at the plate fits within it.

The tonearm gets attached to the plate first - then the plate is simply attached to the armpod with the two bolts. The guide stresses making sure your plate is thick enough to accept the tonearm bolt/s without protruding thus allowing a flush fit with the armpod.

Dear Banquo - my comment was a general one to anyone reading our thread and to those that have emailed me for a copy of my guide. Thank you again for reviewing it.

Since your feedback - I also sent a copy to Raul, Halcro, Nandric, and Lewn for their comments late yesterday. Again if anyone else wants to see it just email me.

I have had a number of people request copies of the guide already. Some in Malaysia and the UK. I do say in it to use aluminum and not steel as it is magnetic. My first one was steel nice and heavy but it is now a bookend. I will be adding more pictures to the guide.

Dear Nandric - I have already posted a link to my set up in an earlier post. The armboard can be seen closer here.

http://www.canuckaudiomart.com/view_userimages.php?user_id=5181&image_id=41886

Note: This guide is strictly to help those that may want to try this out and not a professional document. It is just the way I chose to do it and it worked for me. I am one of those people that like getting to the point and not making things more complicated than they need to be. This was the intent in my approach.

Dear Geoch - it was my intent for the next project to replace my solid aluminum armboard with a brass one and maybe add a panzerholtz tonearm plate on top. From your last post - do you feel this would be worth the expense and effort?
Pictures of my setup were in my link in my last post.

Appreciate any thoughts on this ?

Cheers Chris

Dear Geoch - thank you so much for your thoughts. You are absolutely correct - I can eliminate that wood layer totally and mount the ET directly to the armpod with the one bolt. The mounting post rides on air with 3 of its own couplers. The plate I am using is dried oak and it is firmly held on with 2 - 1" inch machine screws. I used the plate to allow for ease of changing arms but I will be making other pods for those arms so it is not required. Now the important part - how much will it change the sound by removing it.
I will think more about the second part. The adjustable AT616 footers are at their lowest point right now and they adjust much higher to accommodate a higher pod. My problem is at the pod side – I will need a taller one.
So for the interim I think I will replace the AT616’s with the lower mapleshade spikes I was using previously – this will give me the room to experiment with the pod and that layer.

Henry – My VPI 12 arm mounts directly on top – with phono cables out the side. It is very easy to drill a hole into the armpod to accommodate the bottom cables especially if aluminum. But it still won’t look as good as yours. Our imagination is the only limit here. Many ways to skin.

Dear Geoch - thank u for your recommendations. I use the discs under the spikes. I have however been experimenting with different materials under them. The most recent pics in the site link show the discs along with the removal of the armboard top plate.

Will consider the 7 mm brass top plate but have a question.

I like the design of the ET post mount which has one bolt holding it with 3 leveling threaded spikes surrounding it. It can be seen in the link here.

http://www.canuckaudiomart.com/view_userimages.php?user_id=5181&image_id=41907

How do you or others here that have looked into isolation between metallic materials feel, on whether the top brass plate you recommend is attached firmly against the armboard below (easy to do) or if it should ride on air like the ET post mount. More difficult but still easily doable. I would just need to find a place that sells the threaded spike couplers to use with it.

Then the top two levels of the armboard would be riding on air.

Henry - it appears your arm pod top plates are screwed directly to the armpod ? Did you consider this ? What if that top plate was riding on air like the pic in my link ? Would it increase resonances or provide more isolation?

Any thoughts on this ?

Cheers Chris

Dear Inshore - look forward to seeing a picture of the armpod. Just curious as you mention humidity - Is panzerholz affected by humidity as other woods - maple, oak and birch?

Cheers Chris

Dear Geoch – excellent post. You have provided me with three clear options that I understand and am thinking about.

“you can cover the entire underside surface (except the 2 holes) with a very fine velvet textile (extra thin without compliance) in order to damp the 2 metals that are coming in contact”.
This would be an easy solution and I can experiment with different velvet textiles.

“2 bolts may not be enough for the 3 coupling spikes option and can provide space for ringing or even worst a possible diformation of the Brass platform”.
Excellent observation.

I could add 2 more bolts to form a square around the 3 spikes? I can make the Brass plate smaller as well ? The ET tonearm post covers a very small area on the armboard.

“replacement of the upper coupling spikes under the Brass armboard by very tiny bearing balls (if you decide to try this option, by this way becomes easier. I'm anxious about the proper amount of tightness by the big bolts”

I really like this option - picking up some ball bearings is easy but just like torquing special wheels on cars - how do you know how much torque to use on the bearing. I guess I would start with a low torque and listen to familiar recordings – tightening a little at a time. When I used my TNT belt drive I would adjust the SDS by tone so I trust my ears for this.

“You have to choose by trial & error these 3 options unfortunately we cannot predict the results”

Everything we are doing in this thread is uncharted waters–for me that is the allure of it – the discovery – the learning first hand how resonances work in my vinyl setup. We only need to please ourselves. This makes the improvements very satisfying.

I have learned alot by your post.
thank u Chris

Dear Geoch and Henry – thank you for providing very valid points for consideration. My current armpod has served its purpose - it was built to determine if this approach was valid. It was not expensive to make as materials are available and cheap where I live. I am ready to setup up the next one.

It can be done in stages and allow me to use at each stage. I enjoy the DIY approach so would like to continue this way - Thinking of a 4” diameter brass cylinder pod and to mount my Tonearm directly to the top of it with three steel spike couplers on the bottom. This would be the first stage.

I then would make a decision on whether to add a top plate of aluminum to the brass. I need to think more about what has been said here about this.

I was speaking to Bruce of Eminent Technology who informed me that my tonearm uses Cone Point Set screws to level itself to the base. These come in many lengths and diameters.

http://www.radax.com/store.asp?pid=15198

I could mount the top aluminum plate on the brass using the same approach. 3 of these screws close to the perimeter to level it. 2 or 3 bolts would then be placed “just outside of the footprint of the tonearm base” that it will sit on it to secure it to the plate. The plate would ride on air as well as the tonearm. Do you feel this air is an advantage or does it not matter ? Can I get your thoughts on this.

From a DIY point of view - It seems to make more sense if adding this plate to just have it touching the brass at specific touch points with the set screws and bolts and making sure no movement and it is rigid.


I did some research today on materials and pricing.

Metal Supermarkets is located in Canada, the US and the UK.

http://www.metalsupermarkets.com/MetalGuide.aspx?CategoryID=BRASS&ProductID=TUBE_ROUND&ProductSubCategory=360

Prices are for solid brass and SS armpod cylinders. Prices are in Canadian dollars.

4" diameter brass (360 grade) 4 inches high - $152.55 (16 lbs)
3” diameter brass (360 grade) 4 inches high - $79.91 (9 lbs)
4” diameter Stainless Steel 4 inches high - $94.81 (15 lbs)
3” diameter Stainless Steel 4 inches high - $59.71 (8.5 lbs)
3” or 4” (7 mm - approximately ¼ inch) brass top plate is about $10.

Dear Geoch – I am trying to understand the benefit or reason for using the Rollerblock Jr.

Based on what Dgob is saying and the fact the Rollerblock use bearings how much weight are we really talking about when you say “really heavy loaded”.

I ask because I have two 2 ET tonearms. If there is one thing I have learned about that air bearing - is that it is very sensitive. It is set at 19 psi and it needs to be totally rigid and parallel once set and not move or it will introduce coloration, and distortion that is audible.

But I also think that this would apply to other "pivot" arms as well - any movement at all is not good ?

I needed to think about this over night.

I took the soft activity to be any and all the movement that occurs outside of the normal cartridge/stylus retrieval of the signal that needs to occur for us to hear the sound. The tonearm (any type) moves up and down and side to side in normal – use. The actual physical movement of the tonearm is itself a soft activity and necessary. Likewise at the other end (arm pod) movement is happening in the armpod with the resonances – we just cant see it in the material as the vibrations are either absorbed or passed on. With the symposium jr. you are able to see it more clearly.

The footers of an armpod are like the foundation of the house. They however need to be such that they support the structure but also provide for passing of resonances into the platform below not to return up again or absorption of some of those resonances thereby dissipated. This can be done at least in two different ways from what I have learned.

Hard spikes/disks that allow the resonances to pass through and not go back up. Or they can be of a design “soft” and “hard” to absorb some or all of the energy / heat of the resonances and also allow for the remainder of the resonances to pass through. It sounds like the Jrs use this principle.

I have to admit the first time Geoch described this I had visions of a tower shaking during an earthquake. But then if you think about it – as it moves – as long as returns to position in time – before the stylus is on the groove it should be fine. We accept the toearm movement as part of the normal movement – why any different at the other end ?

A personal experience (not audio related) but that relates I believe to this – bear with me. I have a contractor doing renovations to an old property that uses a large copper drain pipe. Whenever hot water is used it would go down the pipe putting energy into it from the heated water expanding it (causing noise) then when the water was stopped, the pipe would again (make noise) as it went back to its cold form form. We were able to cure this by cutting a couple of inches from a section of the pipe and replacing it with a rubber clamp. Now when the hot water is run the energy does the same thing and goes down the drain pipe but the energy makes its way to the rubber clamp (like the Symposium Jrs.) where the energy is absorbed. Drastically reduced noise. For our hobby this energy in the pipe is like those vibrations and the Jrs. are absorbing and passing it onward.
Thoughts ?

Dear Lewn - you can have the most precise and accurate platter/motor assembly - but once you put that crude piece of vinyl on top with all its imperfections - all bets are off.

I have found through this approach that all you want the platter/motor to do is maintain correct speed and drain its own resonances.

Once the isolated (armpod, tonearm, cartridge, stylus) picks up that signal from the vinyl - its on its own merry way and says bye bye to the platter in a continuing cycle.

If your tonearm is mounted on the same platform as your platter/motor, you need to ensure your system is able to deal with the returning vibrations/resonances from the tonearm. Hence we have some very elaborate systems as a ways of doing this.

This is too complicated and cumbersome and $$$ for me – and the reason I like the simple isolated armpod approach. Once my armpod gets rid of resonances, the last thing I want is the resonances returning to play havoc.

Sorry for not presenting this in a more scientific way for some of the members here but this is what I understand to be happening.

We break that resonance loop with the isolated armpod.

The members here using this approach have heard the difference between the two.

Hi Brad - yes the idlers need the plinth to damp the rumble and the inquiries were for armpods going around existing TT's with plinths. A few talked about slate plinths that could be cut smaller to allow for multiple arms. I was planning on doing a plinth for an L75 platter/motor/top plate only with armpods.

Don may see this but I will reach out to him to see if he can provide more info.

Cheers Chris

One 16 lb (7.27kgs) Solid Brass Cylinder - 4" x 4"
$152.55 dollars

Brass bolt to secure tonearm to cylinder .15 cents

Steel spikes / discs to couple the arm pod $20 dollars

Drill bit and tap for making threaded holes for 3 spikes and one bolt. $15

Brass Polish $5 dollars

Unbiased, unsolicited, comments and recommendations from Audigon members - PRICELESS

You can see the raw brass piece here.

http://www.canuckaudiomart.com/view_userimages.php?user_id=5181&image_id=41998

I will try it out this weekend and if it sounds promising I will bring it to a machine shop to round it out and take out the fine scratches

Cheers Chris

Dgob - I have no problem being the guinea pig. Will try to source some locally first. I have found in the past when talking with some of these manufacturers of these products that their experiences with what we are doing is limited.
They can't seem to say yes or no to me and their feedback is very general and ambiquous.

Geoch and his audio community are obviously there already. His comments are based on the Jrs. actual experiences with people so I trust his input as been unbiased. And besides as you say they are not alot of money - again about the price of a tank of gas :)

Geoch - I do have two questions

Are there any guidelines about the weight. Have your members found there is a minimum and maximum weight with the Jrs. and is there a limitation on the height of the object.

Also you mentioned that these are used by the parallel trackers but why not the Pivot arm or any other - since they are balanced as well.
Thinking of the pivot arm I am getting visions of a construction crane on a tower swinging over a job site.

Dear Geoch - and others - everything we do in this hobby is at our own risk. We have all lost precious needles.

Only when this happens do people do one of three things. Get out of vinyl altogether, buy cheaper cartridges or be VERY careful.

I will source some Jrs. and try them. This will give me some time to get used to the sound of the new arm pod. I finally added a system page and posted a couple of pictures for those reading this thread.

For those of you thinking we are doing something complicated here - I walked through my house at 1 pm est today with the piece of raw brass and no holes for bolts or threads in it. It is about 5pm now and I have listened to 2 lps already. I let the system warm up while I put it together.

But this is my 3rd version really so give yourself one day to setup.

I can say with the ET tuned to about 75% right now it is sounding very very good.

Cheers Chris

I have asked some folks who have gone down this path using various metals in an isolated arm pod to post their comments here. I hope they will be able to provide their input.

To me if I had a tonearm with collar - just preliminary thoughts - but anyway to be DIY - You would need to drill collar diameter holes through both the brass cylinder and the top plate and set the spikes high enough to allow the wires to clear. Drilling the holes is easy for a machine shop. The top plate (aluminum?) just needs to be thick enough to allow the tonearm collar to grip and be tightened - then it can be set down on top of the brass cylinder and secured. This could be done by the DIY. Anything more would obviously require a machine shop.

Dear Nandric - I am growing fond of the brass cylinder "as is" and based on what I am hearing am reluctant now to have it taken apart and changed at all.

Cheers

Deat Thuchan - a suggestion while searching for your screws, that you have a glorious opportunity to test out the sp10 on 3 nice footers.

I am sure you must have many lying around ?

Your ET arm :) would require one bolt for it to be mounted for test purposes on a basic arm pod.

Just a thought.

Cheers Chris

Dear Nandric - Hard to believe isn't it. Your right it does move like a ship floating in a harbor when you push on it. But with 18.9 lbs of "very well trained" seamen on board all of them pushing down it doesnt move at all when the stylus touches the groove. They obviously know how important their role is here :) . Totally rigid and in support of this Copernican thread. At least that is what my ears tell me. What else matters more than your ears?

It goes against everything traditional vinyl folks believe in - when it comes to principles and foundations.

Those that try this (with a cheap cartridge) are what we call in my line of work "able to think outside of the plin... sorry I mean box" ! :^)

Cheers Chris

Mass loading is very good – at least that is what my ears are telling me.

Version one aluminum armpod was only a few lbs lighter than the brass - but the weight was dispersed over a longer armboard. The increased force provided by the brass is a positive thing that can be heard. I am not going to provide a lovely description like Dgob provided us with. Let’s just say last weekend I found myself reaching for more lps – some I had not heard in a while – if this is not positive behavior for this hobby I don’t know what is.

Recommendations.

How high is your platter? The higher the platter the more material you will be able to use to get more weight (either a bigger diameter or higher armpod). I have the AT 616’s adjusted now to their highest point – and my tonearm is adjusted to its lowest point. Any higher and it will not work in my setup. I came close and actually had fears when I brought the brass home that I had miscalculated. After analyzing - I breathed a sigh of relief - thank u Bruce Thigpen for all the adjustments u put on that ET arm :)

Symposium Jrs.

With that a source came through and I now have symposium jrs. on their way to me. I understand that they are 1 ½ inches high so my current armpod will not be able to be used for this experiment - as stated my tonearm is set at its lowest adjustment. If anyone can suggest a way of doing this without propping another layer under the sp10 let me know.

So I will get another armpod made a lower one for this - probably about 3 inches high and maybe try it out on my 12" pivot arm as well. I had plans for another armpod anyways

Cheers Chris

Lewn - I disagree - I think that cantaloupe slices would work better than the orange as they are not as acidic, they are in season right now, and studies have shown when talking to workers from their place of origin that they resonate the least : >)

I am having a hoot with this and looking forward to making another arm pod for my other pivot arm and also testing out the jrs on alternate equipment first.

Just a short follow up on my experience with the footers used under the platter/motor.

First I believe it is more important that you have a good solid level isolated platform. I dont think footers should be used as a bandaid for fix platform problems. Fix the platform first.

I have experimented with footers 1) when necessary to up hold a DIY project like this or 2) to change the sound of manufacturers feet.

This applies to one above.

I tried different feet and they all worked. I would still be using the maple shade heavy footers but the at616 came along and they are adjustable. That was my only reason with the different armpods. Its very subjective – we all have different gear and even more different - stands and shelves holding the gear. Experiment with them.

As to weight of the armpod – I don’t know how much weight will work best. My footprint weight changed substantially with the brass - and I believe for the better – it certainly did not get worse – common sense says more is better – but as Lewn pointed out with Vyger some people get carried away. At least I think so. If you have ever picked up 10 lbs of steel or brass with one hand it is substantial – its not going anywhere when coupled with spikes. The next armpod for my other tonearm will again be out of brass, slightly shorter (to accomodate a test witht the jrs. eventually) and will cost $116.
Some people spend this much on an lp :).

Dear Lewn - I would never hate anything that makes great sounds and music. Music is music. How you get there doesnt matter. As long as each of us gets to what makes us happy if that is possible in this hobby. It is a hobby right?

There are complicated and simple solutions to our audio goals. I find as I get older - I turned 50 in February - I much prefer the simpler ones and the ones that get me more involved.

I echo what Raul said - I look forward to hearing your impressions of the MKIII and Thuchan's impressions of his MkII.

FWIW - I knew something was off with my brass armpod. I got home tonight after being away, measured it and it is actually 4.25” tall. I was so like a little kid setting it up last weekend I never bothered to measure. Anyone ordering from Metal Supermarkets better make sure they give you the size you need especially if the little extra will make a difference.

Cheers Chris

Dear Thuchan – thnx so much for the tube book reference. I had such a wonderful time a few years ago swapping tubes when I had an SP8 and changing its sound. I miss that THICK sounding preamp.

I have a large drawer full of tubes from the experience and I have told my fraternal 16 year old twins that drawer may not look like much – but in 10 years what it contains will be worth – well at least 2 – 3 times if not more than what they are worth today. What’s in their dad? Old TV tubes I tell them. And they laugh. “Yeah they are from Holland, Germany former Jugoslavia and other places like that and some from the US. But don’t be in a rush to get them – they may break”.

Prepping for the Juniors

I set up an alternate rig to practice with the Juniors next weekend to see how they work and to see how good they isolate.

See here
http://cgim.audiogon.com/i/vs/i/f/1302538853.jpg

I purposely placed the setup in the middle of the upstairs room containing hardwood floors. What a terrible location but perfect for this experiment - if they work here they will work anywhere. Based on what Geoch said about parallel tracker users using them, I chose to set up my 12” pivot arm on my first armpod (the steel one). I figured this would be of more interest to people here. Again based on some fears about learning how to use the Jrs. (from Geoch’s posts) I mounted a cheap Grado Black on the arm and aligned it with the table and started to get used to it. I have to say with the armpod it took no time at all to align the pivot arm. I set it high so that the Jrs. would fit under the armpod and the arm could be lowered.

BTW for this experiment - I pulled an old SL1200 out of a closet to use as the drive system while I play . I have to say as well how good that SL1200 keeps time. Hmmm - with a little damping and new feet – who knows ?

I will practice with the Juniors here on weekend before trying them under the brass armpod.

Cheers Chris

Dear Thuchan

For me personally it did not meet my needs either in the plinth that I used. 7 layers of birch version. Not an exotic one like you mention.

My current nude set up with isolated arm pod gets me much closer to my personal audio nirvana.

You have a great many tables. All I can say is there are a number of us here that would love your opinion of it in a nude set up with an isolated arm pod. It is a different animal set up this way.

But I am sure you have many higher priority projects so I understand it if this is not possible. Time is so short for these activities I find.

Thank you for your impressions. Chris

Symposium Jr Initial Impressions under Armpod

Okay – I agreed to be the guinea pig for this and now am glad I did.

I say this because I have never tried symposium rollerblocks in the past. We all have various products we use for tweaking - this was not one of them for me. This experiment with the Jrs has to be the most odd and extreme one for me as it goes against conventional thinking – I admit that. But then I am going through a period of experimentation since the nude TT and armpod – we are on a roll. And the costs for the real improvements I can actually hear have been negligible.

What is the easiest way for me to describe for you what using these Jrs. is like under an armpod ? If you have ever used a VPI JMW pivot tonearm (I know there are a great many of these tonearms out there) then you are very familiar with the way the tonearm “shakes and squirms” in its pivot as you lift it and set it over the lp until the needle hits the groove. The Symposium Jrs. under the arm pod “extend” this type of movement down into the armpod so that the armpod and tonearm have the same action and feel. This best describes what its like to use them. It moves around but it does not and will not fall over. It finds its original place again very easily.

They are very easy to set up. But –BOTH surfaces must be level and straight (1) the platform on the bottom, that the Jr. rests on and (2) the bottom of the armpod that the top Jr is up against. If you are using a brass cylinder as an arm pod you need to make sure the bottom of it is smooth.

From my last post the test setup was on purpose, in a bad location suspended hardwood floors. The Jrs. reduced skipping when walking by greatly compared to the regular setup on spikes. The sound difference was noticeable to me even with the cheap old cartridge I was testing with, so I decided to go the next step and set the armpod up next to my sp10 in my sound room.

I believe if you take a cheap but functioning cartridge and put it in a good system, that you will make it sound much better than you think it has a right to sound. Likewise take a good cartridge – put it in a below average system and it will sound like a cheap cartridge.

The cheap grado black cartridge was bearable in my system with the Jrs. It was not bearable without them. Re-read what I just said in last 2 sentences because I am saying a lot here.

Am I ready to try the Jrs. with a $500 - $1000 + cartridge – not yet . Will it make a $500 cartridge sound better – if I was betting on this I would put my money down on it. But I need more time to practice.

On the whole tonearm/armpod/Jrs setup -

You either have the touch or you don’t. I can’t speak for you and I will not be responsible for cartridge failure due to clumsiness or accidents. If you are able to line up a cartridge on your own with the micro movements that are required, than this should be very easy for you.

I found it was easier to put the needle down than it was to raise it at the end of the record. But then I had it setup in the back as a second arm. It is going to take practice. A light touch to keep the armpod from moving. Very definitely give this a try with a cheap cartridge. You need to try it out to see if this is for you. As our friend Geoch said – not for the faint hearted? But the results are definitely rewarding to those that are able to do it.

Cheers Chris

I believe Henry your first post is still very relevant – I added 6 words at the end based on this experiment so far.

“The tonearm is now the centre of this ‘Turntable System’ and is the most important element. It must be rigidly held on a base which is perfectly flat, non-magnetic and relatively immune to structure-borne and air-borne feedback. This base must ideally have no contact with mechanical or electrical interference and must under no circumstances, move or deflect in any manner” (once the stylus hits the groove).

Juniors

Everything is still very hard and rigid between the platform and the armpod with the Jrs.

http://cgim.audiogon.com/cgi-bin/vs.pl?vopin&zz1301604425&viewitem&o3&1303046315#item

The fact the armpod moves “prior to” the stylus touching the groove is irrelevant. The fact it moves no more once set down is VERY relevant. I say this because if it is moving that big 12 inch arm would have distortion, would skip and the stylus would be toast.

My VPI arm does this exact same movement prior to touching the stylus. Who here has a VPI that can share their thoughts on it?

Obviously weight on the Jr. bearing is critical. My first steel armpod block of steel which I am testing with is 18.9 lbs.

What I tried was very early preliminary testing ONLY with a cheap old cartridge. It proved TO ME per Geoch's earlier post that this concept functions - no more - YET. I picked up an MM based on Rauls suggestion and listened to it last night on my ET with the brass armpod to get a feel for it. It’s a decent cartridge – I will mount it on the VPI and continue testing using the Jrs. with it and report back.

You have to have the light touch with this when interacting with arm 1) lowering the stylus 2) lifting at the end. DONT try this out when you have had a few glasses of your favourite beverage :)

Can someone else come on here and describe in their own words "the action" (shaking and squirming) of the VPI JMW arm prior to setting the stylus down in the groove ? I say this again because it is the same action the armpod does prior to the stylus touching the groove. It would help others to visualize what is happening.

Cheers Chris

I wish I had Dertonarm's Uni-Protractor - setting up a pivot arm is so much more work than a linear tracking arm !

Henry I just emailed you and some of the others here a short 59 sec video of the Symposium Jr. setup that i did with the video camera on my phone. I hope u get it - it is 16 meg. I will need to do a shorter one. If anyone would like more than a picture just email me. I am not putting it on youtube - yet.

I got the new cartridge running on the VPI arm with the Jrs.

Some more impressions.

Unless your cue lever is remote controlled :) you need to have a smooth and very fast one to lower and raise the stylus. As little interaction touching the arm pod is preferred. As Geoch mentioned in an earlier post lubrication of the lever - definitely - ensure it is working properly.

Initial setup sounds really nice probably set up about 80% - room for improvement - regarding the sound - in my system the VPI 12" arm is not as fast as the ET arm but still nice in its own way.

Cheers Chris

Dear Lew - I have confirmed what Geoch said in an earlier post - as long as the platform is level - gravity and the extra weight on top allow the bearings to find their spot every time. The more weight the quicker its found. The bottom of the armpod and your platform needs to be smooth -flush with the top and bottom Junior.

Dear Thuchan - thank you so much for the info on the
Toho TH-80. They share Henry's Copernican philosophy and the basis of our discussions here with isolated arm pods and platter/motors.

http://www.vinylengine.com/library/toho/th-80.shtml

That small block of steel that is in my video is almost 19 lbs.

My brass cylinder is 4" diameter and 4.2" tall and over 16 lbs.

Sorry for the quality of the video using my phone. It is very difficult to make my 16 year son (camera man) stand still for 60 seconds. He doesnt share the passion (yet). maybe that is a good thing :(

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