Silent Running Audio’s Ohio Class XL+² Equipment Platforms

If you haven’t fully addressed vibration control in your audio system, that means you still have a final frontier to conquer. And the SRA Ohio Class XL+²  platform is a great place to start your quest. I’ve seen my fair share of DIY attempts: granite slabs, maple boards, sand boxes, and inner tubes to name a few, many piled up like Dr. Seuss contraptions. While any of these alleged solutions will change the sound  of your system, I’ve yet to hear one that consistently reveals more music throughout the frequency range. Often, gains are made in one area at the sacrifice of another.

Until now. And trust me, I was highly skeptical until the very end. The cable world is renowned for its empty promises, and the field of vibration control is no different. Most of it is hit-and-miss. If you peel back the curtain, precious few anti-vibration vendors have any real credentials to back up their products.

Kevin Tellekamp, the brains behind SRA, is a music lover and audiophile, but he also has an extensive background in math, physics, and acoustics. Oh, and he holds more than 50 worldwide patents on vibration control. His “day job” involves solving vibration-related issues for NASA and the US Military (hence, the ship-related product names) along with some other very high-profile customers. At the time of this review, Tellekamp was working with a NYC hospital to isolate its CT scanner from intruding vibrations in order to increase its resolution.

Component Couture

Each of SRA’s Ohio Class XL+²   equipment platforms is a made to order component. SRA takes many things into account when performing the necessary calculations to optimize a platform, for the given piece of equipment. The result is perfectly suited to your gear and according to SRA, their designs are “future proof.”

Each Ohio Class XL+² is designed and manufactured with a specific component in mind, but should you change or upgrade, as audiophiles have a habit to do, the platform can be recalibrated for the new item, at no cost to it’s original owner.  In the rare case that this is not possible, a very aggressive trade in allowance will be made, provided your platform is still in excellent condition.

SRA currently has a database with thousands of different pieces of gear on file, but as Tellekamp pointed out, “if it’s not in our database, we’ll get the measurements.”

They call this Component Specific Design, and even take into account the exact type of footers used by each equipment manufacturer.  Because of this, additional cones, balls, etc. and any kind of additional mass loading is not recommended as it will diminish the component specific design of the SRA isolation unit. Tellekamp is quick to point out that the Earth vibrates somewhere near 3 hz, “What on Earth, weighs more than the Earth? Mass loading is simply not effective.” Another critical aspect of the SRA designs is that they do not use any material in their products whose performance decreases over time.  As anyone who has used a vibration control product using Sorbothane knows, this material compresses relatively quickly and loses its ability to damp vibrations, especially when stacked within an enclosure per Tellekamp.

Each Ohio Class XL+²  is hand built and because of the different parameters involved can range in price from about $1,000 each to as much as $8,000 each.  Lead-time from order to delivery is usually about a month.  Tellekamp and his team consider every part of the design, including the room, and how its products interface with their surroundings. Be it rack based or floor based application, SRA always concentrates on three main problem areas first, regardless of any special circumstances, they are:  Air-born energy, Floor based energy and equipment born energy, which proves to be largely dependent on the first two, but there are some residual vibrations internally from power transformers, etc.

The pair of platforms I received for my Burmester 911 mk.3 amplifiers cost $3,000 each and arrived in massive wood crates. Packaged more carefully than the $30k Burmester amplifiers they would be supporting, their construction quality immediately became evident; workmanship and finish are flawless. My review samples came in high-gloss black, but three standard colors are available and the platforms can be done in two optional custom colors for an additional cost. Tellekamp sent me another email stating, “They take about 2-3 days to achieve final effect, enjoy!”

A Vexing Moment

At this stage of the game, I was still highly skeptical.  With a 12-inch thick concrete floor and a solid-state amplifier, how could I be subject to vibration issues? Tellekamp was quick to correct me, “Vibration will travel quickly through this floor. Stand at one end in your bare feet and have someone bounce a golf ball at the other end, you will feel it unless there are deep voids or saw cuts separating the solid mass.”

Not wanting to risk the sound changing in the slightest by powering the amplifier on and off, a friend slid the platform into place under the first 911, while powered.  Now, listening could begin in earnest!

In the middle of listening to some recent Blue Note remasters, I could immediately hear a darker background with instrument decay having a wider degree of contrast.  Of course, this is where even the most seasoned listener may suspect that the mind is playing tricks – that new upgrade has to sound better.  Moving on to a number of tracks that I was very familiar with, the change with the SRA platform was almost spooky. Everything I played possessed a more organic, relaxed feel, and didn’t come at the expense of any of the dynamic punch my system offers.

Over the next few days, these effects increased, and I felt psyched out by the whole experience. Every time I played something that I’ve heard many times before, more music came to the fore. It was time to make to the switch to the 911 that wasn’t supported by the SRA. What a difference. The soundstage collapsed somewhat and there was a level of cloudiness to the presentation that I hadn’t noticed before. Everything sounded slightly more electronic and less natural. The effect was akin to unplugging the amplifiers from the RSA Maxim power conditioner and plugging straight into the wall.  Think about the impact being similar to the effect of making a substantial upgrade to a component. For example, when listening to the same phono cartridge on my Rega P3 and P9, the tonality is similar. But the P9 retrieves more detail and offers more dynamic contrast.
With a pair of identical amplifiers at my disposal, it was incredibly easy to go back and forth for comparison rather than to have to rely on aural memory. Because at this stage of the game, you want to believe that the shiny new thing makes a difference.  And fortunately, the difference is not understated—the SRA platform offers a marked improvement in every way and takes nothing away from the musical performance when in place.

So, what’s in the Box, Doc?

Though I’ve seen some hints and glimmers at what lurks inside the SRA platform, I still don’t know.  But whether it’s some kind of unobtanium goo from Area 51 or a gigantic wad of Hubba Bubba, it works even better than claimed and like the monolith in 2001, it’s well camouflaged.

After spending considerable time with the SRA platforms, I consider them essential to my system’s performance and would put the effect on par with what I’ve achieved with careful attention to power line conditioning.  If you have a system capable of great resolution and dynamic swing, you will notice about 50% of the effect that the SRA platforms offer instantly and the rest in about 48 hours.  It’s not subtle.

While I can’t suggest placing the Ohio Class XL+²  underneath your amplifier(s) highly enough, I would also suggest optimizing the rest of your system first, so that you can take full advantage of what the SRA platform has to offer.  If you still have major room or setup issues, the added benefit of this component will not be as evident.  Much like adding premium cable to your system, if you still have a big plasma screen between your speakers, or a large area of bare floor, these are much bigger bang for the buck improvements that need to be addressed first.

SRA will be sending us one of its Craz racks in the near future for evaluation, and we’re very anxious to observe the improvement it makes to the rest of the reference system. For now, I give the SRA Ohio Class XL Plus 2 platforms my highest recommendation. If you own a high-performance audio system, I guarantee it will offer a level of performance you didn’t know existed.

The SRA Ohio Class XL+²  Equipment Platform

MSRP:  Equipment dependent


Analog source AVID Acutus Reference SP w/SME V and Koetsu Urushi
Digital source dCS Paganini (4 box stack)    Sooloos Control 15
Preamplifier Burmester 011
Power Amplifier Burmester 911 mk. 3
Speakers GamuT S9
Power Running Springs Dmitri, Maxim and power cords
Cable Shunyata Aurora

We revisit the new Haley and Jaco from Running Springs

Running Springs_1I’ve been using Running Springs power line conditioners with excellent luck for just over five years now and have upgraded my current reference system to their flagship products, the Dmitri (for all of my line level components) and the Maxim (for my power amplifier, on a separate 20 amp circuit), while the Haley that I purchased quite a few years ago is still working well in system two.

Recently, Running Springs has made a series of upgrades to their line of power conditioners, the Duke, Jaco and Haley that encompass more than the carbon fiber face plates you see on the front. The squishy, sorbothane feet have also been replaced by new, carbon fiber feet and there are a couple of carbon fiber damping plates inside as well. But the biggest improvement comes from the addition of their new platinum foil capacitors. RSA designer Dan Babineau said, “These were all simple but effective changes that make a marked improvement.”

Running Springs_2Definitely, a cost effective improvement

The cost increase over past models is about $500 on the Jaco and $400 on the Haley, and a direct comparison between the old models and new reveals the current spec units better in every way. The new models are not light years ahead of the old, but when listening side by side, the current version does present an even lower overall noise floor, with less AC grunge getting through and less resulting grain in the overall presentation. In essence, the new versions take you closer to the performance of the Dmitri and Maxim.

Current RSA customers that need to have the latest, greatest version do not need to sell their current product. The factory offers an upgrade for the earlier models; the Haley can be updated for $350 and the Jaco $500. These are factory direct upgrades (to keep the cost reasonable) and you will need to contact RSA to get a return authorization. This upgrade is not restricted to the original owner, even if yours was purchased used, the price is the same.

The best part of the upgrade is that the unit once upgraded, will not only receive a full factory check up, but an additional 3-year warranty. It’s like buying a certified pre owned used car.


Running Springs continues to raise the bar in power line conditioning and their latest upgrade renews their commitment to their customer base as well. Highly recommended.

Manufacturers Information

MSRP: Haley ($1,899 – $3,499) Jaco ($3,599 – $4,599) depending on configuration

Running Springs Maxim Power Line Conditioner

RSA MaximAs a long time owner of Running Springs power conditioning products, I was very anxious to hear the effect of their newest power conditioner, the Maxim on my system. Unlike a number of other power product manufacturers at the recent Rocky Mountain Audio Fest that made outrageous claims for their power products (two of which have already been returned to their companies already), RSA designer Dan Babineau simply told me, “If you like your Dmitri, the Maxim uses the advancements I made going from the Haley/Jaco/Danielle series of our products to the Dmitri, but with additional filtering. It’s been optimized for high power/high current amplifiers.”

The new Maxim has an MSRP of $4,500 and the optional HZ power cord is another $1,495. The standard Mongoose power cord is $695.

In six years the RSA line conditioners have been the only ones I’ve been able to use in my system, that I could plug a power amplifier into without negative results; mainly the squashing of dynamics at modest to high volume. Every other power conditioner I’ve tried has fallen down when I’ve plugged my CJ Premier 350 or Burmester 911 mk.3 amplifier in. I’ve heard a couple do a respectable job at cleaning up the power (however, not as good as the RSA), but the minute you plug a big amplifier, the magic is gone.

In my reference system, most of my line level components (preamplifier, phono preamplifier, turntables and DAC) are plugged into the Dmitri on its own dedicated 20-amp circuit. My Naim CD555 has it’s own dedicated 20 amp line with a Running Springs Haley and the power amplifier on another 20 amp line with a Jaco.

How much further can it go?

I was particularly interested in torture testing the Maxim because I was working on a few high power amplifier reviews for our December issue. We’ve got the SimAudio Moon W-7 monoblocks at 500 watts per channel, the Burmester 911 mk. 3 at 350 per channel and the McIntosh MC1.2kw monoblocks at a staggering 1200 watts per channel as part of the lineup. And there’s a JL Audio Gotham hanging around with the ability to put out about 4000 watts in short bursts, so I couldn’t think of a better trial for the Maxim.

The Maxim took me by surprise because I was already content with the Jaco in my system, paired with the HZ power cord. Though I approached this with some skepticism, the result of swapping the Jaco for the Maxim was not subtle.

Immediately, I noticed a lower noise floor overall. This is instantly perceived as an increase in volume, because what your ear interprets as an increase in volume is actually the difference between loud and quiet. So if you want your system to sound louder, you can get more juice by making it quieter. Everything appears louder for the same given SPL.

Even more exiting was the increase in soundstage width and depth. With the Jaco in place, it seemed like the soundstage went about a foot beyond the speaker boundaries of the Gamut S-7’s that I used as the benchmark for all of my amplifier tests, but with the Maxim in place on the same music, the soundstage went about four feet beyond the speaker boundaries.
RSA Maxim_rear

Keep in mind, with both power conditioners, the tonality of acoustic instruments stayed consistent and I could still wind out a big power amplifier without the leading or trailing transients getting shaved off, but in every case, the sound was bigger and slightly louder with the Maxim in the system. This effect also remained consistent, whether I was using the big Macs or my CJ LP70S, which is only 70 watts per channel.

The serious torture test was playing music at moderate to high levels with the big power amplifiers I had at my disposal. When those big blue meters on the MC1.2kw’s start swinging up past 600 watts per channel, you need current and that’s what the Maxim delivers. If you take a glance on just about any HiFi forum, you’ll see any number of posts where people throw their arms up and mention that their system always sounds more dynamic and lifelike when they just plug back in the wall. With the Maxim it’s just the opposite. Whether you are blasting Shostakovich or Snow Patrol, your system will exhibit a level of dynamics you didn’t think possible.

RSA Maxim_cord

Is it real or is it Memorex?

Of course the human ear is fairly adaptive and it’s very easy to get used to the sound of one component over another after a while. After about a month of continuous listening with the Maxim, I plugged my Jaco back in the system to see if I really “needed” a Maxim. Everything shrunk down by a substantial amount and the system got slightly quieter, even at low volumes.

Keep in mind a power conditioner should not affect the tonality of your system at all. You shouldn’t get deeper bass or a more extended high end. Properly implemented, a good power line conditioner and associated power cords should merely deliver 100% of what your components are capable of delivering. No matter where you live, your power is moderately lousy to really lousy, because there are a lot of distortion components present in the line when power is generated. In short, things should get quieter and bigger. That is precisely what the Maxim does.

So, do I need one? You bet I do! If you have a modest system, it doesn’t make sense to buy a $6,000 power conditioner and power cord. Grab a Haley and enjoy the benefits. But if you’ve got a state of the art system and you’re already at 11, thinking there’s no where else to go, rest assured; there’s one more click on the dial with a Maxim.

The Running Springs Maxim Power Conditioner

MSRP: $4,500 (alone) HZ power cord, $1,495, Standard Mongoose power cord, $695


Analog Source
Spiral Groove SG-2 w/Triplanar arm and Lyra Skala cartridge

Digital Source
Naim CD555

Conrad Johnson ACT2/series 2, Burmester 011

Power Amplifier
Burmester 911 mk.3, CJ Premier 350, CJ LP70S, McIntosh MC1.2KW monoblocks, SimAudio Moon W-7 monoblocks

Speakers YG Acoustics Anat II Studio, Verity Audio Sarastro II, GamuT S-7

Shunyata Aurora

Speaker Cables Shunyata Stratos SP

Power Running Springs Dmitri and Haley, RSA Mongoose power cords, Shunyata Python CX power cords