Publisher’s note: This article is co-authored by Fred Crowder and Earl Weed.
RevOpod Black and Chrome
In this review, I explore the effect of a relatively new product, Arya Audio RevOpods, vibration control feet on the sound of my system.
Over the years, I have used a variety of different devices to damp/isolate my equipment both from external noise sources and/or help deal with vibrations created within the equipment. As you might guess, this is complicated because of possible interactions between the damping footer and the surface on which the equipment is sited. For this review, I used the RevOpods on two different stands (a Finite Elemente Pagode Reference and a Harmonic Resolution Systems). I have found both to be excellent, but somewhat different. Likewise, I like to begin by placing the footer being tested under a single piece of equipment, switching back and forth with my reference footers (Stillpoints Ultra 6’s) which are very effective and quite neutral, and the footer under review. In practice, both the Stillpoints and the RevOpods rely on ball bearings to transform vibrational energy (micro-vibrations) to heat thereby dissipating the energy. In the case of the RevOPods, there is an additional compliant element.
Over time. I inserted RevOpods under additional pieces of equipment including my digital gear as well as the power supplies of my Audio Note UK preamp and phono stage. Toward the end of the review period, I also tried the footers replacing Simply Physics Cerabases in a second system with staggering and stunning effect to determine if the effects of the footers were as pronounced under a less expensive set-up.
Nuts and Bolts
I contacted the manufacturer to seek a bit more information on how the RevOpods work and on how they differ in design from Stillpoints. I thought that it might be useful to include his response to both questions.
1) with respect to how the pods work in layman’s terms:
“When it comes to vibration, it is important to note that every mechanical system has a certain resonance behavior and, if the wrong type of damping material or vibration control strategy is used, it can make vibration issues actually worse. Audio applications are in that sense quite challenging because the vibrations we are dealing with can be very broadband and developing efficient vibration control strategies, that are working across a wide frequency range, is not easy. We spent almost 2 years developing and testing different vibration control strategies until we found a suitable solution. The approach that achieved the best results in the end, and is now incorporated in the RevOpods, was not even one that you would usually find in audio applications but rather in civil engineering.
For the vibration control of heavy structures such as bridges, civil engineers make use of so-called pot bearings. These bearings use elastomers constrained in a short cylinder, or pot which become significantly more compliant under loading thereby providing vibration isolation. By combining this strategy with a spherical bearing it is possible to achieve highly efficient vibration isolation in all degrees of freedom. The challenge, however, is to realize this approach in a very compact form while optimizing it for the requirements of audio applications. After countless prototypes we succeeded in refining and adapting the pot bearing concept to broadband audio applications and implemented it in the RevOpod damping feet. It is the first product to offer our proprietary vibration control system and offers a superb damping performance.
The RevOpod consists of 35 high precision manufactured parts per each damper, using lowest tolerances for a tight fit and perfect functionality of the intricate mechanics. It features a unique height adjustment mechanism where rotation of the outer ring moves an inner element up or down, translating the rotary motion of the outer ring into linear movement of an inner cylinder. This allows for a precise adjustment in just 50µm steps (=2mils), each indicated with an audible “click” and ensures that RevOpods stay always in full contact with the component it supports regardless of its set height, thus providing perfect structural connection at all times. In addition, RevOpod can easily adapt to uneven surfaces through a single pivot Delrin® Exopod.
All of RevOpod’s structural parts are CNC machined from solid billets of highest quality stainless steel while the contact element to the floor is made of Delrin® providing outstanding internal damping properties. To achieve the high gloss surface finish of the metal parts, we use a highly labor-intensive method where each part is polished by hand until a “chrome-like” mirror finish is obtained. For the black versions, an additional Titanium-Nitride (TiN) coating is applied on top of the mirror-polished surface using high temperature and vacuum environment.”
2) with respect to how they differ from Stillpoint Ultra 6’s:
I have both on hand and they are similar in their effects but to my ear are “voiced” differently.
In vibration control there are two important principles, coupling and decoupling. Depending on what the goal is, you might want to apply one or the other approach or even a combination of those to achieve the desired results.
Based on the information I have about Stillpoints, they appear to use the coupling principle primarily, as I don’t see any vibration damping mechanisms like polymers or springs even though they talk about vibration isolation, which is a bit confusing. In any case, Stillpoints appear to channel the vibrational energy away from the component which they are supporting, to the structure they are standing on. In that context I like to use the example of Newton’s Cradle where you release a steel ball of a pendulum and once it hits the next steel ball the energy is transmitted all the way through several balls to the other side when the last steel ball is receiving (almost all of) the initial energy and swings out due to the conservation of energy and momentum principle. The Stillpoints are essentially a ramped-up Newton’s Cradle. To achieve good results using this (coupling) approach requires the whole system (including rack, floor etc.) to work very coherently together. It’s similar how for example an Open Baffle speaker can sound great in a certain (suitable) room but terrible in another (because such speakers interact much more with the room than for example a closed box speaker). The Stillpoints are essentially an Open Baffle speaker equivalent of vibration control footers if that makes sense.
But coming back to the comparison with the RevOpods, we use a combination of coupling and decoupling. We found this approach to be the most effective and it also allows us to ensure consistent results across different systems (we found it less critical than achieving similar results using other approaches). The coupling part in the RevOpods is realized through a spherical bearing structure which deals with horizontal movements. When exposed to horizontal vibrations the upper part of the RevOpod can move independently of the lower part (contained in the Delrin element) which is facilitated by the spherical bearing structure and is damped through gravitational force on the one hand and a damping ring on the other hand. For the vertical vibrations, the RevOpods use our proprietary pot bearing system described above where the energy is absorbed through a multilayer structure of elastomers and stainless-steel elements thus mitigating vibrations.
- (Page 1 of 2)
- Next page →
