Thread: Isoacoustics zaZen isolation platform

Originally Posted by Mechnutt

Is anyone using the zaZen TT isolation platform? I am thinking about buying one. I was wondering how well it works.

We just got rid of our oak floors and replaced them with Hickory which is denser and harder than oak. We even put a sound deadening underlayment in. Now my turntable picks up every little vibration. I can sit on my sofa 12' away and tap on my thigh and hear it through the TT. I had no such problems before. I am sure the new floor has a tighter fit and the wood is harder so it is transmitting vibrations more. My TT is a 1970's Thorens TD-145 with a spring suspension that I dampened a bit and it has custom plinth I built out of very dense and heavy cocobolo wood which sits on sorbothane feet. The aluminum deck sits on the cocobolo supports that is lined with silicone. The insides are lined with GT Mat. So overall the TT is well dampened. It sits on a steel 6 tier rack with frosted glass shelves that sit on rubber grommets with about 215lbs. of gear on it. Total weight is over 300lbs.

I emailed Isoacoustics and they thought that the zaZen is the right product for my problem. Ideally, I would like to install a TT shelf but the wife said no go to that.

Interesting development, sorry to hear about the new issues arising.

Just characterizing a "technicality" here to provide a foundation for discussion: to "dampen" something is to make it moist.

"Damping", e.g. mechanical damping (e.g. as what we refer to in the USA, a car or motorcyce system component known as a "shock absorber" does), and what I believe is what you're referring to, is an entirely different thing: it can attenuate and mitigate the propogation and tranmission of vibration, and/or resonances that may arise from a fundamental vibration frequency or source of vibrational energy.

From the description of your audio system and room environment and construction, what it seems you're dealing with is another "system" that gives rise to, and exacerbates vibration and resonances, rather than damps and mitigates the problem. This is likely why the problem has gotten worse instead of better with the recent changes.

First up is the Thorens. Because it's a spring-based suspension, it can be susceptible to vibrational energy imparted to the springs. Any energy imparted to the springs can cause the springs to oscillate, which often makes the problem worse. The springs need to be damped (not "dampened") so that they absorb the initial energy (e.g. the bump a car wheel experiences), but stop oscillating almost immediately. Undamped springs don't do this, in many cases, they start oscillating more and more. If you've ever seen a car wheel with a blown shock absorber (or as the Brits more accurately refer to it, a damper; gee, there's that term again) on the freeway at speed, it can be go into a uncontrolled pattern of "bouncing". much like a tennis ball on a court. This is because the "shock" is not damping the oscillation of the spring after the first bump. It's just my hypothesis, but I think the cocobolo custom plinth might be part of the problem. If memory serves, it's a hard, heavy, and dense wood, and as such, might have a higher intrinsic frequency of vibration than the original materal the plinth was made of. Also, the GT mat and silicone are just adding mass, with yet another set of vibrational frequencies, to a plinth that is likely already too massive. My recommendation would be to get rid of all that stuff if you keep the turntable.

A lot of folks are of the view that making a turntable plinth more "massive" is better than a less massive (lighter one), but personally, I'm not at all an advocate of this. Folks need to understand that everything can vibrate or resonate given the right type of energy at the right frequency. I have a buddy that was having similar issues with his Linn-Sondek (a design similar to your Thorens). After he moved it; he said "I'm having problems with the Linn's arm almost bouncing off the record." I told him that it was likely to the ringing of his floor caused by his speakers (big M-L's and their subs) and he said, "What? The room is on a concrete slab floor." and I countered with, "What makes you think concrete can't ring* or vibrate? Just ask the folks on Market Street in San Francisco during the 1906 earthquake if concrete can vibrate."

Oh, and sorbothane can vibrate, too.

Personally, I think you'd be well-served by making the lightest and stiffest turntable plinth, rather than a heavier and more massive one. Ever see the plinth on a Rega Planar 6, Planar 8 or Planar 10? It is very, very stiff and also very, very light. It's designed to transfer any resonant frequences away from the turntable and tonearm bearing as quickly as possible with the most effective damping. This is why it's constructed of a stiff laminate sandwiching a core of Tancast 8. This gives a very light plinth structure that dissipates resonances very quickly and effectively.

Here's a photo of the Rega Planar 10 I reviewed earlier this year. Look how little actual "plinth" there is.



You want as little plinth (which can resonate) and as little plinth mass as possible....not more. For your Thorens, my recommendation would be to take all that crap off your heavy and dense cocobolo plith, take the 'table, bearing and arm subassembly out of the cocobolo plinth, and put the turntable sub-assemblies back into the original Thorens plinth.

The other parts of the system that I think be problematical are the 6-shelf steel rack and glass shelves. It's tall and just exerts more movement and thereby, leverage (and subsequently energy) into any components sitting on it. This will be at it's worst if the Thorens is on the top shelf, because the leverage from the rack supports is greatest at the top. Also, the glass shelves are likely contributing energy as well; glass is well-known to be a very resonant material, and can literally ring like a bell at the right frequency.

So...with all due respect, I think you've gone in the wrong direction with the turntable system.

My recommendation would be to put your TD145 back in it's original plinth, and mount it on a wall shelf, much like the kind Rega sells and has advocated the use of for years (and for good reasons). The plinth of the Thorens will have less mass, and it will be sitting on a mechanically stiff but low mass support.

My no. 1 recommendation, though, would be to sell your Thorens and get a Rega Planar 8 (or 10, if it's in your budget).

Oh, BTW, you can download a free app for your phone called "Hamm Seismometer". Start up the app, and place your phone on various parts of your system, and you can see visually where all the vibration is occurring. Very useful diagnostic.

* - Think concrete can't ring? Think again: Coupling VS Decoupling: What you NEED to know! - YouTube

Sorry for the longish "dissertation"; hopefully these suggestions will get you back to a setup that's much less prone to vibration, footfalls and the like.

Cheers.