AOM Logo July 1999

Symposium Acoustics Rollerblocks
Listening in Isolation

Blair Roger

l really like chopsticks. They're simple, they're cheap, and I can even eat soup with them. They're an example of perfect form and functionality combined. So is the Movado 'Museum' watchface. And so are the Symposium Acoustics Rollerblocks.

In the Beginning…
Some very clever audiophile realized that there were minute vibrations in every audio component and if they could be damped, even a little, the sound improved. It all started with cones. Cones of every description and composition. Some of the names were pretty smart: Tiptoes, Tonecones, Clonecones, and so on. Then people began combining them with squishy, spongy pads made out of Sorbothane for better performance. We have arrived at the point where it is accepted as simple fact that any serious music listener must use some type of vibration control beneath his components, whether they are digital, analogue, solid state, or tubed.

How does it work, Daddy?
In theory - and I can only state theory because I have not made any measurements or objective study of the subject - cones act as a grounding device, leading vibrations down and away physically from the component. If they are pointed downward, the mass of the component is concentrated on a tiny point, not unlike a stiletto heel so that the effective weight of the object is multiplied in great quantum leaps. Therefore, the component is coupled to the ground with massive forces on the point of the cone. The component is rendered far more stable, and resonant vibrations have a one-way path to ground. If we think of the generic tonecone as a mechanical diode, passing vibrations in only one direction, then reversing the cones and pointing them upward would have the effect of freezing the component in space. An interesting idea, but I've never noticed much improvement by doing this because the point fuses the body of the cone to the component making it into a foot. This just creates a super-stable tripod platform with little energy draining potential. Placing a rubbery Sorbothane pad between the base of the upward pointing cone and ground might improve vibration isolation slightly by absorbing gross vibrations at moderate to high frequencies. Everything I've tried, apart from cones, from little rubber feet to bisected tennis balls, all suffered from the same problem: they only damped out vibrations over a very limited range of frequencies.

There have been other vibration damping techniques put forward. One technique primarily relies on adding mass, in this case a box of sand, on top of the component and/or placing it on a massive, sand-filled base. This appears to work because a lot of audio gear comes in thin sheetmetal boxes, and audiophiles are placing them on equipment racks that isolate them so they ring like a bell suspended in space. Increasing the mass of the component and the ground on which it rests will result in clearer sound reproduction. A brute force method, but one that pays dividends for a small investment. Nevertheless, internal vibrations, such as those in the plinth of an unsuspended turntable or in a circuit board of a tube pre-amp, remain a problem if they aren't drained away.

What if you had almost no financial constraints in solving the vibration problem? I understand that the ultimate solution would be to obtain a Vibraplane, which is a sort of air-filled waterbed for electron microscopes, lasers and so on. A Vibraplane takes the opposite approach to the solution. Instead of trying to freeze the component in space or drain away internal vibrations, it lets it float like a cork on the ocean, riding on the waves of ambient vibration while simultaneously absorbing the minute internal ones too. What a great idea. I'd be happy to confirm that these things work if someone would loan me one. And that's the catch. They're very, very expensive.

And now for something completely different…
Rollerblocks are the result of some truly original thinking. I can't imagine how Peter Bizlewicz, President of Symposium Acoustics, came up with this idea. The product is an example of pure inspiration and a perfect blending of form and function. They are unlike any other approach to vibration damping and component isolation I have ever seen or heard of. And they really work.


Rollerblocks come in sets of three. There are two parts to the 'system'. The bases are made of black anodized aircraft aluminum and measure 2 inches by 1 inch by 0.75 inches (L x W x H). They are very light and appear to be filled with some synthetic foam visible through the generous perforations on the underside. Centered and pressed into the top surface is a polished cup, slightly less than 1 inch in diameter. The other part of the system is a finely polished ½ inch chromium steel ball bearing. The motion of the bearing is constrained only by the slight, precise curvature of the cup in which it rests. The ball bearing, cup, and foam filled base have been developed as a superior mechanical interface for draining internal vibrations away from components to ground.

In use, the set of three Rollerblocks is placed in a triangular configuration underneath the component. When they are properly installed, the component will actually rock to-and-fro if pushed gently in any direction in a lateral plane. I estimate the frequency of the rocking motion to be around 2 Hz and it stops after about two or three cycles. I have to say I was quite amazed the first time I saw this and realized the implications. External vibrations starting at 2 or 3 Hz are very effectively damped because the Rollerblocks allow the component to float in a precisely controlled lateral plane. At the same time, in the vertical plane, minute internal vibrations and their reflections are drained to ground through the super hard chromium ball bearings and compliant bases. I like to think of it as a Vibraplane on the rocks.

What the Rollerblocks do in practice is simply astonishing. I was loaned two sets of them, so I put the first ones under my Jadis Orchestra integrated amplifier. Tube amps are rife with vibrations from the transformers. Such vibrations are bound to cause microphonic effects in the power tubes, subtly blurring the sound. My first impression, listening to Miles Davis playing My Funny Valentine (Cookin' OJC-128), was of a vast drop in the noise floor. Suddenly the musicians stood out in their own space and instrumental timbres took on a new sweetness and richness. Strangely, the music seemed louder even though I hadn't changed the volume setting. Bass lines were more tightly defined and the pitch was clearly better centered.

I put on a studio recording by the late jazz vocalist, Mel Tormé from his album, Top Drawer (Concord Jazz CJ-219), that opens with a close-miked a capella passage. I listened to all the new details in articulation and to the harmonies of George Shearing on piano and Don Thompson on bass. The improvements were, once again, unmistakable. Then I put the second set of Rollerblocks under my Well-Tempered Turntable and played the record again. Suddenly, I could hear ambient reverberations in the a capella passage that weren't there before. I could hear the ambience of the studio that had been obscured by vibrations trapped in the plinth of the turntable. Tormé's image took on an even more realistic presence, as new vocal details, like subtle sounds emanating from the throat, appeared for the first time. I turned to my listening partner and we both shook our heads and smiled.

Rollerblocks can also be used with the bases doubled-up for further sonic gains. If you have two sets (and a helper) you can invert the second base and place it between the ball bearing resting in the lower base and the component, making a sort of sandwich. The component should still rock freely even in this configuration. I set up my vintage Fisher 500B (tube) receiver in the living room this way. The depth and image specificity on FM broadcasts of live concerts was greatly enhanced. Announcers' voices took on more depth and richness. The Fisher sounded sweeter and more detailed than I had imagined possible. I enjoyed the new sound of my 500B and the Quad ESL-57s so much that I left the Rollerblocks in place for several weeks.

The instructions that come with the Rollerblocks mention one final tweak: a drop of Teflon or Silicone lubricant can improve the performance slightly. Of course, I had to try it and - yes - it does work, smoothing out the midrange and treble in a very pleasing way by eliminating (would you believe?) bearing chatter.

I must mention that there are optional bearings available made out of tungsten carbide. They are much harder than the standard chromium steel balls and therefore should provide better transmission of vibrations away from the component. While I believe that the optional bearings are an improvement, I was satisfied with the standard bearings in all applications except for the Fisher receiver. This is a matter of taste and something you will have to try for yourself.

From what I have experienced with Rollerblocks, I can say with confidence that they will improve the sound of almost any component. Digital aficionados are particularly smitten with the effects - I'll have to take their word for it because my main system is strictly analog, but I have no reason to doubt their enthusiasm for the results under DACs, transports and one-box units.

If you've been thinking about upgrading a major piece of equipment, especially one of the tubed or digital persuasion, try a set of Rollerblocks first. This is an incredibly good product: beautifully made and packaged, and a great value too. You will love the way this product reveals subtle recorded details, and sweetens the sound of your favourite recordings.

Rollerblocks Component Isolation Products
Manufactured by Symposium Acoustics
Wayne, New Jersey
phone: (973) 616-4787
Price: US$249.00/set of three, Optional tungsten carbide bearings: US$25.00 each
Source of review sample: Canadian Distributor Loan
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