A Copernican View of the Turntable System

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.

Chris,

I failed to notice that the original suggestion was to try the rollerblock "juniors". These should indeed be far more stable under mechanical interactions than the normal rollerblocks (which I use). Nandric is correct that you'll have to suck it and see and I thjink you are right to give them a go. Maybe you could even talk to the people at Symposium first. Anyway, there is a set of juniors for sale on eBay now ($90).

Good luck with your experimentation and do let us know how it goes.

Chris,

Sorry, just one other brief thought.

If you look at the details and approach of the Equarack people, you'll see there is a major concern about mass loading/weight of component to get the best out of viscoelastic supports. As I mentioned above, I had major problems when trying noted components on one of my Symposium platforms and so you might want to look into this weight compliance factor in making your decision. Athough, at only $90 you might just think it as well to just get them and experiment!?

Either way, I look forward to hearing how it performs in your rig.

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