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(With a Second Look at the VR Series isoBASE)
Audio Equipment Review By: Stero Times, Frank
Peraino
August 2004
THE PROBLEM
 For
the flower child, there were good vibes and bad vibes. For
the Beach Boys, we know they had good vibrations. With all
due respect to Brian Wilson and company, for the audiophile,
there ain’t no such thang as good vibrations –
only bad vibrations. If you don’t buy into the philosophy
that vibration and unwelcome resonances degrade the audio
signal, I suggest you move on to something else. If, like
me, you agree that component isolation is important, read
on.
The Earth vibrates. Everything is prey to the planet’s
fundamental resonant frequency of about 0.5 to 2 Hz, along
with its seismic activity, winds, tides, etc. Add to this
all the noise we humans generate: automotive traffic, railroads,
airplanes, heating and a/c systems, refrigerators, dancing
circus elephants. These vibrations lie primarily in the subsonic
range but are large enough in amplitude to affect anything
in contact with the ground, for our purposes, a house and
the hi-fi system it encloses.
Audio vibrations can bring a host of detriments to the audio
signal: image smearing, bloated, tubby bass, diffuse soundstage
presentation, timbral coloration, homogenization of transient
attacks, and opacity (as contrasted with transparency) just
to name a few. I have spent considerable time and effort attempting
to address these ills.
THE QUEST
If you are like me (God forbid, in which case I feel for
you), you have probably tried at least one if not numerous
roads to gear isolation. In the ever-growing audio-accessory
market, there has been an explosion in the number of tweaks
and materials offered to deal with vibration. These products
range from pucks, points, cones, ball bearings and combinations
thereof (constructed of brass, ceramic, aluminum, titanium,
etc.), to various platforms, racks and shelves (of various
design and construction including pneumatic, spring loaded,
sorbothane, carbon-fiber, acrylic, maple, Corian, granite,
marble, etc., etc.).
I have both auditioned and lived with a great many of these
products. Virtually all of them had an effect on my audio
system, and not all of it positive. Some devices improved
image focus or bass response but proved too analytical. Some
ameliorated that nagging glare or edginess but produced an
overly warm, fuzzy sound or resulted in a loose or tubby bass
response. It seemed there was always a price to pay for what
subtle improvement was gained. Approximately a year and a
half ago, I began my search for state-of-the-art audio isolation
platforms for my Tenor 75Wp OTL mono amps. My focus was on
my amplifiers because I was now going to be placing them on
the floor rather the bottom shelf of my former component rack.
My quest led me to the Silent Running Audio Ohio
Class XL isoBASES™ under review here. I first learned
about Kevin Tellekamp, chief technical guru and designer of
the SRA line, from a former colleague at Ultimate Audio. I
had also heard and read various accolades about Kevin’s
products from other reviewers and SRA owners. My objective
was to find the best isolation product, period. I wasn’t
looking to needlessly jettison gobs of cash on a wild goose
chase. However, I was willing to spend what I needed to squeeze
every ounce of performance I could from my amplifiers. After
hearing and rejecting a number of static suspension systems
and the usual suspects, the ball-bearing and cone systems,
I called Kevin Tellekamp. That call led to many more and to
my conclusion that Kevin is one of the true gentlemen in high-end
audio and a gifted designer/engineer.
THE SOLUTION
When SRA was seeking an effective principle to apply to audio
isolation, a look back at Sir Isaac Newton’s theories
provided guidance – “For every action there is
an equal and opposite reaction.” Stated in audio speak:
“Every motion [vibration] generates a counter motion
[vibration].” The question then becomes: “How
does one effectively attenuate this vibration [motion]?”
The answer, which would likely meet with Newton’s approval,
is to design and provide an effective counter-motion, (i.e.,
a suspension), which, if implemented properly, would generate
friction and dissipate thermal energy.
Enter SRA’s top-of-the-line Ohio Class XL plus isoBASES™
as the ideal implementation of this Newtonian response. In
case you are wondering where the “Ohio Class”
designation comes from, Kevin has a background in submarine
resonance control technology, which is what first attracted
me to SRA. If the military entrusts Kevin with the sonic isolation
of its hyper-sensitive sonar equipment in multi-billion dollar
nuclear submarines, I could probably trust him with my stereo
gear. The mission: to attack vibration.
SRA’s implementation of its counter-motion technology
via its “raft” and “suspension” system
is not easily described. The Ohio-Class XL plus isoBASE is
actually two isolation units in one. Kevin developed the upper
housing with derivatives of what the audio world commonly
refers to as coupling and rigidity. The lower section’s
design conversely employs the concepts of de-coupling and
mass. Rather than utilizing a “one-size-fits-all”
approach, other than its budget priced
Tremor/Less audio islation platform, all SRA products
are component-specific designs with a number of factors taken
into account before construction begins. These factors include
component size and weight; location and weight distribution
of interior and exterior parts, (e.g., large transformers,
drive units, outboard flywheels, etc.); equipment typography;
and the materials used in the component’s construction.
In addition, the end-user’s listening room also figures
into the design equation. After all this information is compiled,
the following design/manufacturing process begins.
- Modeling. A data stream processes no less than 130 entries
to produce a platform: The component’s blueprint if
you will.
- The main housing assembly. A proprietary, high-pressure
nanoparticle composite of over 250 distinct products and
chemicals are compiled under a nitrogen blanket, which is
to say, in an airless environment consisting of hundreds
of thousands of microscopic vacuums.
- The raft isolation frame system. SRA’s military-grade
isolation system can be compared to the frame of your car.
This element of the design allows SRA the opportunity to
deal with the thermal energy dissipated during the counter-motions
discussed above.
- The raft isolation suspension system. Because SRA begins
the design process with exact specifications, SRA can then
set precise suspension parameters. The isolation system
is dynamic by design and specific to its component. Kevin
provided an analogy: Compare the size, weight distribution,
materials and design differences between a school bus and
a Ford Taurus. Both vehicles have a suspension system consisting
of shocks, springs and/or struts. However, no one in his
right mind would claim that you could use the Taurus’
suspension system under the bus or vice versa, and so it
is with our stereo systems. Audio isolation components are
of different size, weight, materials and purpose. Thus,
if one is going to develop a suspension to effectively counteract
each motion a particular component generates, in order to
operate optimally, the suspension system must be designed
to counteract the motion (vibration) for that particular
component.
"Needless to say I was delighted to find that my bass
response, while more articulate (as was the case with the
both the VR series and many of the cones and footers I have
tried), was deeper with an improved harmonic texture."
Through the storage and dissipation of thermal energy, this
enormously complex suspension system has the ability to rapidly
alter its properties as required. These changes are triggered
by room-borne, air-borne, and/or equipment-borne episodes.
Inside the SRA housings are bladders filled with a thermally
reactive copolymer that, according to Kevin, can change its
darometer, (i.e., its stiffness or softness), with extreme
speed. Viagra should be so versatile. Think of Jell-O and
the way it moves from liquid to solid. The relative volume
and chemistry of the copolymers can then be varied in order
to match the isoBASE to its component. If this sounds like
mad chemistry to you – it did do me too, until I heard
what it produced.
But why not use air you might ask? Kevin is not a big proponent
of air as an isolator, especially if the design is inexact
and non-specific. As Kevin puts it, “Air carries the
music from your speakers to your ears at 1200-1300 feet per
second at 70 degrees F (at about 50 Rh). Why would you want
to use air as the ideal isolation medium?” Makes sense
to me.
The Jell-O analogy is useful to a point, but it doesn’t
provide any indication of the much more difficult task of
building the custom isoBASE. The copolymers used by SRA in
its isoBASES achieve a liquid state only in an air-free environment!.
This, as mentioned above, requires SRA to assemble the isoBASES
under a nitrogen blanket. Design overkill? Not so fast oh
skeptical one! The result is an air-tight platform containing
a thermally reactive Jell-O -like substance capable of changing
its density in response to the specific vibrations caused
by that component’s typography. I know of no other isolation
product that can make such a claim.
Protruding from the bottom of the isoBASE are spiked footers.
Their cylinders also contain copolymers, but whose reaction
capability has been chemically blocked, enabling the high-tensile
steel spikes to operate as shock absorbers. The isoBASES are
then coated with an aggregate that includes ground rubber
and crushed glass, its purpose, to dampen vibration and shield
for RFI. For the final touch, the piano-gloss-black finish
of my Ohio Class XL plus isoBASES is on par with any speaker
and even any automobile finish I’ve ever seen. Nothing
I’m aware of in the way of acoustic isolation compares
with SRA’s attention to detail, design, technology and
manufacturing process.
Before shipping, all SRA products are tested with military-grade
procedures. (SRA also does work for the Defense Department.)
The test equipment runs the gambit from accelerometers to
oscilloscopes to anechoic chambers, with a few more items
between. All this sophistication and technology won’t
amount to a hill of beans, however, if the SRA isoBASES aren’t
effective at both controlling unwanted resonance and which
translates to an improvement in the sound of your system –
so read on!
THE SONIC EFFECT
My adventures with SRA began with the mid-level VR 3.0 isoBASE.
I initially bought the VR 3.0s for my former reference Tenor
75Wp OTLs and immediately noticed their positive effect. The
VR Series isoBASES are fine looking products with a gray textured
coating. The units range from 2”- 3” in thickness
and cost from $300 to around $800 per platform. Although I
was thoroughly satisfied with the results, Kevin offered to
custom-build a set of Ohio Class XL plus bases without obligation
for comparison purposes. Who am I to argue with him? I asked
him how much better he thought the Ohio Class XL plus would
be than the VR 3.0’s. (I had the two-piece platform
with a “pre-base” for use on my floor with thick
carpet). He opined that the Ohio Class XL plus would likely
give me a 10-15% improvement. It turns out that Kevin was
being conservative and I’m getting ahead of myself.
When I first placed the VR
3.0 isoBASE under my Tenor OTLs, I was pleasantly surprised
at how easily I noted the improvements. I actually expected,
notwithstanding the sophisticated design, to have to strain
to hear differences, if any, over the other isolation products
I’ve tried. Those other isolation methods did provide
some benefits, largely subtle. For the most part, those changes
were a relatively modest tightening of bass response and an
equally modest improvement in image focus. However, those
other products also produced certain negative effects, ranging
from added brightness to a disagreeably analytical sound.
One of the first things I noticed with the SRA VR 3.0, and
even more so with the Ohio Class XL plus isoBASES, was an
increase in both the width and the depth of the soundstage.
But the even greater surprise was that the residual glare
or brightness imparted by the other products I tried was now
gone. With no glare or brightness I was sure I would be sentenced
to tubby or wooly bass. Needless to say I was delighted to
find that my bass response, while more articulate (as was
the case with the both the VR series and many of the cones
and footers I have tried), was deeper with an improved harmonic
texture.
After about four months with the VR Series isoBASES, I switched
to the Ohio Class XL plus with my typical Doubting Thomas
attitude expecting to hear little if no improvement. What
did I hear? Well, I have to take what, at first, looks like
the easy way out -- I got more of everything I heard with
the VR Series. An experience with one of my audio fraternity
brothers best illustrates the impact of the Ohio Class XL
plus isoBASE in my system.. My buddy Brian has been with me
through most of my audio journeys and is now a certified audio
sicko in his own right. He too now fights the seemingly never-ending
battle of extracting the most from his system. He had been
by for a listening session during the last week the VR Series
isoBASES were in place. I hadn’t told him that I was
getting the new Ohio Class XL plus isoBASES. He came by one
night the next week and we put on two or three of our reference
discs. He asked me what in hell I’d done with my system!
He was convinced I had changed, at a minimum, speaker cables
or interconnects. Like me, he judged the bass to be deeper
and more articulate – in fact, the best he had heard
in my system yet, and he also thought that it sounded harmonically
richer and illuminating - more sparkle with less glare was
his supplemental diagnosis. It took a bit of convincing to
make him believe that all I had changed was the platforms
under my amplifiers.
This episode notwithstanding, it wasn’t until I got
more used to the SRA isoBASES under the Tenors that I began
to realize what I now had was a much more realistic musical
landscape. If you’ve ever gone from a conventional 4:3
aspect television to a wide-screen 16:9 ratio television,
you know that when you first fire up that new baby there are
those nagging wide spaces on the sides of the screen. The
picture is being squeezed into a square because the station
is transmitting a 4:3 ratio to your 16:9 screen. Your television’s
remote has an aspect button that lets you expand the 4:3 image
to sort of “fit” your new screen size. The resulting
problem, however, is that the faces and images are now somewhat
distorted. People and images on the screen seem heavier and
distorted. That anorexic super model now looks nearly normal
and that person with a few extra pounds is now virtually obese.
As if that isn’t bad enough, the picture’s top
and bottom is now cut off. However, if a station is actually
broadcasting in 16:9 or if you rent a movie which is formatted
in a16:9 ratio, when you watch that channel or pop that DVD
into the player, voila! – all is right with the world.
Well, so it is with the Ohio Class XL plus isoBASES. I get
a more coherent and a more natural and balanced presentation.
I’m able to hear deeper into the music because the size,
images and placement of the performers is 16:9 rather than
4:3. It is the sonic equivalent of your television’s
“aspect.” Button if you will. I also found my
system to be producing a more organic sound. Instruments and
voices, while more clearly delineated, are melded together
in a mellifluous way that allows the listener to enjoy both
the fine detail and the big picture simultaneously and without
effort. I have always felt that the most delicate balancing
act in both designing equipment and in compiling and matching
the components in your own system relates to the ability to
extract detail and resolution without making the end result
sound analytical or fatiguing. Every time I think I have coaxed
the last drop of resolution and detail from my system, that
it is impossible to extract more from my source material,
I find something that proves me wrong. Enter the Ohio Class
XL plus. These bases are remarkably more effective than any
isolation product I have tried and at least 20-25% better
than SRA’s own VR Series. As I was listening to a disc
by Doc Kupka’s Strokeland Superband, I was amazed that
I could now understand previously undecipherable lyrics. (The
liner notes don’t provide them.) A lowered noise floor
might also account for my sense of increased clarity.
Be that as it may, this latest assault on vibration has produced
the most natural, unforced, refined and panoramic presentation
I’ve heard coming from my system thus far. I finally
found an isolation product that doesn’t produce as many
ill effects as it does sonic benefits. The Ohio Class XL plus
isoBASES are not only the most visually stunning and technologically
advanced isolation product I have ever used, they are, by
a large margin, the best sounding and, alas, most expensive
I’ve ever used.
As noted above, I am by nature skeptical, particularly with
respect to audio accessories. Admit it, tell me you haven’t
looked at a $4,000 interconnect or speaker cable or a $2,500
power cord or that $500 footer and asked yourself, what’s
in there that can possibly be worth that kind of money? I
certainly have. Now before all you good and honorable designer
cable manufacturers ride me out of town on a rail, let me
explain. One, cables and power cords can make a significant
difference. Two, not all high-priced cables and power cords
justify their cost of admission. However, I have defended
a number of effective mega-buck cables by offering this hypothetical:
Two of my all-time favorite artists, Stevie Wonder and Ray
Charles, are sitting around talking about their audio systems.
One day an audio dealer drops in and says to the guys; “Hey,
we’ve pulled out a $500 component from your system and
replaced it with a $3,000 equivalent. Let me play a few of
your favorite cuts and see if you like it”. If Stevie
and Ray enjoy and value the improvement in the system’s
performance, would they care if that replacement piece was
an interconnect rather than an amplifier? I think not. The
problem is, we look at that meager power cable or interconnect
and their apparent lack of intrinsic value and it just doesn’t
seem right that we should pay as much as we pay for a good
amplifier, which is, after all, big, heavy, and stuffed with
parts. However, if that meager interconnect or power cord
has as dramatic of a positive effect on our enjoyment our
system, why should we balk at the price? Easier said than
done, I know.
So, I again warn you, these SRA Ohio Class XL plus isoBASES™,
visually stunning as they are, do an excellent job of concealing
the intensive labor, materials, attention to detail, design
and testing that goes into them. Do not make the mistake of
judging this book by its elegantly simple cover. The Ohio
Class XL plus isoBASES are an upgrade equal in all respects
to a major component replacement.
Downsides? Once again, the Ohio Class XLs are expensive.
Conventional wisdom recommends against a $2,000 platform under
a $2,000 amp. The money might be better spent on a $4,000
amp. Better yet, the VR Series or SRA’s new low-cost
Tremor/Less bases might be just what the vibration doctor
ordered. Moreover, one of SRA’s chief selling points
– that the isoBASES are custom built specifically for
your component – can also be a negative if you replace
components as often as Osama bin Laden changes bedrooms. You
may have a harder time selling the isoBASE than a one-size-fits-all
butcher block. However, if you have a state-of-the-art component
or one you intend to keep for the long haul and you want a
truly effective isolation platform to allow you to extract
everything, ideally, that component has to offer, I submit
that nothing comes close to the Ohio Class XL plus isoBASE.
We live in an age of “smart” cars, “smart”
computers and even “smart” household appliances.
Add to that list, the SRA Ohio Class XL plus isoBASE. It is
not only a “smart” isolation device it is indeed
the class valedictorian! My highest and an unequivocal recommendation!
Specifications:
Component-specific, custom-built audio isolation platforms
conforming to the width, depth, weight distribution, equipment
typography, construction and, if applicable, the irregular
contours of the components they support.
Price: Varies Based on audio isolation component
by Frank Peraino
SteroTimes
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