Mechanical energy- the analog domain
The energy distribution in an analog turntable is of primary interest if a phono stylus is to transcribe records accurately. In order for perfect playback to occur, the stylus must be perfectly aligned and oriented to the record groove, and one other thing: absolutely motionless with regard to its reference position. Intefering with this theoretical perfection is the reality that mechanical vibration, like waves distorting the surface of a calm body of water, is busy at work not only pushing the stylus around, but is also deforming and distorting the groove walls and tone arm, changing their relative shape and alignment to the stylus.

Of course, these changes are extremely subtle, on the order of microns (millionths of an inch), but since groove modulations can be even smaller than this, they become significant. As recently as 20 years ago, the role of subtle extraneous vibration and its deleterious effects upon analog playback were widely unknown, if ignored altogether beyond the token "spring" suspension to keep a stylus from skipping out of the record groove (caused by gross displacement of the turntable chassis). In the late 70's, a certain audio reviewer noted a "phenomenon" whereby if a turntable was supported on a "cheap,"wobbly table, it sounded better than if on a "sturdy" one. At the time, the reviewer could not explain the reason for this phenomenon. The reason why the wobbly table "sounded" better is clear now: it acted as a crude isolation device, decoupling the turntable from floor-borne vibration.

Enter Isolation
You can think of the analog record groove/stylus interface as a kind of 3 dimensional sculpture in motion; as vibration is introduced not only to the groove but also to the pickup mechanism, this "sculpture" changes its form, with the result that the electrical signal faithfully follows these changes and sends a distorted signal to be amplified and later transduced into sound. In an attempt to avert this inevitable catastrophe, "isolation" platforms have been developed which attempt to "cut off" the turntable from the outside world, in an attempt to save the stylus/groove interface from the horrors described above. While some may be aware that perfect isolation is impossible at our present stage of technology, far more fail to realize that it is also undesirable.

Why Not Pure Isolation?
While it is intuitively obvious that the record groove itself should be free of extraneous vibration, what is not so obvious is the many ways that vibration can be introduced to the turntable in ways other than through its support surface. First and perhaps most obvious is airborne vibration: sound waves which travel through the air. Further, there are other sources, not so obvious, and these are generated by the turntable itself. The motor, belts, bearings, and most significantly, the phono stylus (as it vibrates in the record groove) contribute significantly to the circulating energy in a turntable/arm system, and it is vitally important to provide a place for this vibration to go - and not come back to your cartridge stylus.

Until perfect, frictionless motors, belts, gears and bearings are developed, the only way to deal with the by-products of friction is to dissipate it. Most turntables make no attempt to absorb this energy internally except by serendipity: the construction materials used may combine in fortuitous ways to dissipate energy, but ultimately, there will always be some energy left over. This energy will circulate through the chassis of the turntable, and if it doesn't find any escape into a greater ground, it will eventually reflect back to the cartridge, where it will be faithfully included in the signal being generated.

The feet of a turntable are the only solid pathways to the greater ground that circulating energy seeks; but more times than not, this energy, trying to escape from the turntable, encounters a dead end: rubber feet.

Why Rubber Feet Don't Make It
In a miserly attempt to "isolate" the turntable from its surroundings, rubber or sorbothane is very often employed in the form of "feet," or sold to be used as separate "isolators." To paraphrase the late, great Frank Zappa, rubber feet don't make it. Rubber doesn't conduct energy well; worse, it conducts energy at some frequencies, absorbs at others, and stores and releases energy at other frequencies. In other words, a rubber or sorbothane foot acts as a kind of passive equalizer/phase shifter- with a "frequency response" setting that is woefully far from the ideal, or "flat." Also, because rubber has non-linear storage and release characteristics, it can do more damage than merely upset music's timbral color; it can actually interfere with and distort all-important time information by introducing complex, spurious group-delay characteristics back into your system. The bottom line? Rubber feet and pads are a sonic no-no.

...a rubber or sorbothane foot acts as a kind of passive equalizer/phase shifter- with a "frequency response" setting that is woefully far from the ideal...

Click to enlarge image

Why Our Platforms Don't Bounce
The Ultra is a preferable support for analog turntables over "rubbery" devices, because it provides a nearly ideal mechanical ground without introducing any spurious reflections. Any "bouncy" support, such as those that employ rubbe, sorbothane, or air bags (which are basically rubber tires), will store and release energy back into the turntable. This "bounce" usually has a resonant frequency somewhere in the low to midbass range - and will at first sound like more bass, because energy is introduced to this mediating device and then "redistributed" over a broad spectrum which corresponds to its resonant frequency- which is, more times than not, squarely in the midbass region. Many people appreciate at first blush the "warm" tone that this class of device imparts to the sound. However, this is extraneous distortion, and has nothing to do with the original signal. Worse, by adding extraneous energy back to the signal, "blurring" of details occurs as the original signal becomes corrupted.

Eventually, these types of "isolating" components can become fatiguing, because they obscure musical information and make hearing more difficult and listening a task rather than a mode of relaxation. Worse, they can skew the sonic cast of the entire system in the wrong direction- which can result in other devices, just as wrong, being used to "counterbalance" them. Ultimately, the entire system can become a "balancing act," where the loss or change of just one item can make the entire system unlistenable. The only way to cure this problem is to start over from scratch, and rebuild the system piece by piece.

Providing the Ideal Mechanical Ground
An Ultra platform, used with hard feet or metal points with a turntable, will give the energy in the turntable a place to go, be dissipated, and not reflect back. "Softer" or "light" shelves can't provide the proper impedance matching, and are just scrambling vibration into different patterns- and not getting rid of it. Glass, stone, and undamped metals are unable to dissipate energy; most of it will simply reflect back into the turntable, creating "micro echoes" of the signal, further distorting it. To summarize, then, the best way to get rid of vibration is to either give it a place to go, or change it into a different form. The Ultra does both.

A Specific Example with the VPI TNT + Flywheel
Click on the banner below for pictures and a discussion of one such installation of the Ultra Platform with a VPI TNT+ turntable.