February 2008

Balanced Power Technologies BP-2 Power Conditioner
Review By Scott Faller
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  Power conditioning has been a contentious issue for years. Some people firmly believe in cleansing the power that enters our audio and video systems where other people look upon power conditioning as snake oil in a different colored bottle. Personally, I reside in the former camp.

I've been using some sort of power conditioning for years. As a DIY'er, I've always tried to concoct my own, never wanting to spend the money it takes to buy an audiophile approved conditioner. I've done everything from the large industrial Corcom passive filters to cheap ONEAC transformers. They have all worked (at least) in some minimalist way.

A number of years ago a good friend of mine over in Europe turned me onto the DeZorel line of passive power filters. I invested in one of their 20 amp filters which at the time, was quite affordable. Compared to my el cheapo attempts at conditioning, the DeZorel worked marvelously. The backgrounds got blacker, everything became more defined, pretty much everything you'd hope a good power conditioner would do.

Then came my obsession with tubes. I have to say that when I was just doing a tubed preamp, I didn't experience much of an issue with noise. Sure, I had a noisy dimmer or two around the house that would cause a buzz in my system but those were easily defeated by turning off the light.

As time went on, I installed several dedicated 20 amp circuits strictly for my audio systems. Each of these was a worthy upgrade making significant improvements to the sound. Eventually, my system became completely tubed. Tubed CD players, DAC's, phono preamps, preamps, active crossovers, and tubed amplifiers to drive the woofers and the wide range drivers.

If you aren't aware, tubed gear has a tendency to pick up noise that rides our incoming mains, more so than solid state gear. I can't say it's the fault of the tube gears power supply design as there are only so many ways you can design a power supply for tubed gear. Unlike solid state gear that (in some cases) the power supplies are nearing a half farad (500,000 microfarad) of filtering capacitance and power storage, tube gear is lucky to have 500 microfarad of total storage and filtering. In turn, some tube gear can let noise through if the power isn't clean.

Such was the case with my system. As I added more and more tube based designs, the noise floor raised a bit each time. It was nothing too major, mind you, but it was definitely there. As it happens all too often, we become accustomed to the way our systems sound. We tend to listen past its inadequacies and lavish in the music. So when people that would visit my home and ask about those low level hums and buzzes, I would shrug my shoulders and say, "Hey, its tube gear.", as if that were a good answer.

I'm sure this has happened to nearly all of us, once you begin to notice something about your system that you don't like, it begins to drive you absolutely crazy. Such was the case with those low level buzzes and hums. So I set out on a quest to fix the problems. My first call was to a friend up in Brooklyn who knows power and filtration better than I could ever dream.

I explained the issues and we proceeded to troubleshoot each piece of gear. As a result we found a couple of pieces that had floating grounds. I fixed those and had marginal success in lowering the noise floor. That still wasn't good enough for me to keep my sanity.

Next, I had my gear spanning two separate circuits within the house. This created a ground loop potential. Sure enough by putting my front end and amplification on the same dedicated circuit, it lowered the noise floor another minor notch. Still, when music wasn't playing I could hear the buzz.

Next up was to bring an "official" electrician out to the house. I'm lucky in the fact that I work with some of the biggest and best trained electrical companies and electricians in St Louis so with a phone call, I had one of the top electricians out at my house. Denny (the electrician) brought a van full of tools. The best tool in his bag of tricks was his Fluke 43B single phase power harmonics analyzer. This little gizmo measures power harmonics, captures voltage sags, transients and inrush current.

As part of the exercise, we checked all of my internal wiring (self performed) focusing on the dedicated outlets for my system. We didn't find anything major so in buttoning up, we tightened all of the connections and closed that chapter of the story. Next we shut off all breakers feeding the rest of the house and brought them on individually trying to isolate the source of the noise hoping it was a transformer or ballast back feeding into the system. Still no luck.

The next step was to provide an additional ground as my only ground was the one to the utility company's incoming mains (essentially a floating ground). We sunk an 8' copper ground rod and attached a solid piece of #6 then landed on the grounding lug inside the panel. Still no help (sound wise) but as a byproduct this gives me much needed lightning and ground potential protection coming from the incoming mains. Half disgusted but fully appreciative of his efforts, I decided to try a different route.

Enter Chris Hoff from Balanced Power Technologies. Chris came over with a sack full of goodies for diagnosing problems. The most notable was the simple AudioPrism Noise Sniffer which detects EMI/RFI interference, identifies noise source (process of elimination), and tests line for filtering effectiveness. With this simple noise tester, I found out that my DeZorel wasn't doing squat for catching all of the noise (obviously), at least the noise that the AudioPrism was identifying.

Chris also brought his Fluke 41B power and harmonics analyzer which reads individual harmonic distortion out to the 31st harmonic. After installing the Fluke we discovered that on the 15^th harmonic I relatively high harmonic distortion. I also had additional (but lesser) distortions in the lower harmonics.

Since I had previewed Chris to the noise problems I'd been experiencing, Chris brought along one of his BP-2. This is a rather attractive, true power conditioner (rather than a filter) that looks quite like a solid state power amp. It has a ¼" thick machined aluminum faceplate and a powder coated black finish on the rest of the 1/8 inch thick metal case. On the backside is a lighted rocker power switch, a Furutech FI-10 IEC connection, a binding post that can be used as a separate system ground and finally five Oyaide SWO-XXX Ultimo, gold and palladium plated duplex outlets. Needless to say, from outward appearances, this has all the makings of audiophile excess... gotta love it.

When you break into the inside of this puppy, you find more of the same excess. The first thing that leaps out at you is the huge, custom manufactured, Plitron isolation transformer.

Sidebar Time
OK, in power conditioning there are several ways to clean up the power. The first is the cheapest and simplest as DeZorel, Brickwall, Corcom and others do. They install a simple passive CLC filter (or a derivation thereof). This filter is nothing more than a simple first, second or higher order filter that rolls off in the high frequencies attenuating the noise at those frequencies that the particular filter is designer to attenuate. They are generally very effective given their design limitations (read = they don't utilize an isolation transformer or attempt to  regenerate or regulate your power).

The second is a simple isolation transformer such as the ONEAC and the smaller Richard Gray products. These consist of a simple isolation transformer. Often they incorporate some form of passive filtering like the previous filters. These are also quite effective giving their design limitations (read = they don't utilize a balanced power topology transformer).

There are a few manufacturers that produce units that regenerate, supplement  and then regulate your incoming power all without the use of a transformer, banks of batteries and an inverter. This is a personal statement as I've not played with any of these units but I find their claims a bit more than dubious. As such, I will refrain from further comment on these units.

The final is a true balanced isolation transformer such as in the BPT. Here, the BPT provides isolated secondary windings within the massive torrid which has balanced outputs. The term Balanced refers to the electrical properties of the power. Without getting into a huge technical dissertation, unbalanced power is what is coming out of our single phase distribution panels. Our voltage, that comes in via two terminals, consist of the hot and the neutral. Accompanying these two terminals is a ground. When you take a reading on your wall outlet between hot and ground, you get 120 volts. In turn when you take a reading between your neutral and ground, you get zero volts as the neutral goes to ground. In a balanced power system, when you take a reading between either leg (hot or neutral) to ground, you should read 60 volts with both being 180 degrees out of phase with each other.

That was an overly simplistic look at power conditioning. Sure, there are dozens of variants to the designs that I mentioned. I, by no means, wanted to cover every scenario out there. Nor was this intended to be a technical crash course in electrical theory. I realize there are gaping holes and exceptions in what I just wrote but I wanted to give you a simplistic view of the most common power conditioning schemes available to us.

OK, Now Back To Our Scheduled Typefest
As you will notice in the pictures, BPT has also installed an X rated capacitor across the duplex outlet terminals. An X rated capacitor simply means that the capacitor is UL rated and certified that it can be installed across a 120 volt, 60 hertz hot and neutral (read = your incoming mains) without shorting, blowing up or causing a fire. You should not do this with your typical audiophile capacitor so don't get any ideas. I know many of you are doing this with a relatively well known brand of audiophile caps. You should ask yourself, or better yet the manufacturer if they can produce a UL certification number showing it is X or Y rated (Y rating is from hot to ground). If they can't, you are putting all you hold dear at risk. If you ignore this certification and your house burns down, don't expect your insurance company to cover the claim. You've been warned.

The other thing you will notice is a small black box sitting just below the Furutech IEC inlet. This little device is manufactured by Environmental Potentials. Though Chris won't admit to what's inside this hermetically sealed, patented little black box, after visiting EP200's website and reading through their application guide, I have a much better understanding of what this device actually does. Essentially, this device provides selective filtering much like the previous passive filters but also performs voltage clamping (surge protection) and absorption of current and waveform anomalies. The actions and formulas are rather complicated but they are fully explained in the EP2000 Application Guide complete with test results conforming to IEEE testing standards. For those meter jockeys among us, there should be ample information there to quell your suspicions that this is more snake oil in a different shaped black box.

Now, according to BPT, the Plitron balancing transformer does a great job filtering common mode noise and the EP filter does a great job filtering differential noise which makes this combination great pairing. As a last bit of technical information, you might have noticed that the BPT doesn't have any form of voltage regulation. There is no means to provide constant voltage regulation like some of the other "conditioners" (see my personal comments above).

BPT has a whole host of features that I won't go into individually. Instead, let me give you the list from their website so you can get a flavor of the engineering that goes into each power conditioner. Custom low-noise, low temperature-rise, tight load regulation, high-isolation type toroidal  transformers from Plitron Manufacturing. You can visit the BPT website for even more information regarding their design philosophies. Chris also some impressive graphs showing the reduction of noise due to the use of the Plitron NBT transformers. It's well worth a look.

To Quote Paul Simon… The Sounds of Silence
Each of us has had one of those eye opening experiences where you've installed a piece of gear and found that everything else you've auditioned was just plain wrong. Well, after installing the BPT I knew exactly how much money I have wasted over the years trying to eliminate the crap riding my mains.

After Chris and I plugged the BP-2 into the wall outlet, we tried the AudioPrism noise sniffer again and guess what, the noise was gone. I confirmed this again and again by plugging it directly into the wall outlet and then again into the BPT.

Next up was some music. I put on some Allison Krauss and pushed the play button on my Bolder modified Squeezebox. Literally three notes into Gravity, I turned to Chris and said, "This is going to cost me a fortune, isn't it?". He just smiled and continued listening to the tunes.

Lets forget the fact of the extremely low noise floor and that the hums and buzzes were all but gone but the music had changed in my system once again. The change was very much for the better. The sound and intonation of the system was the same but the focus had gotten extremely better. No longer were the instruments sort of wide and round, they now were sharper and clearer. The soundstage depth retreated further by a solid two to three feet and that is saying something for my forward sounding Lowthers.

As I played with the BPT in my system over the next few weeks and months, I realized that everything about the sound of my system had improved. I now had even less grain, the bass firmed up a notch or two and the soundstage not only got deeper, it got wider. And yes, to coin an overused audiophile adage, the music flowed even more effortlessly than if had before.

The overall improvement to my system by adding proper power conditioning was quite dramatic. And yes, it did cost me. Fortunately the BP-2 with a few upgrades is still relatively affordable at just over $1200. Sure, that is a fair chunk of change but for those who want the last bit of refinement and noise removal from your system, it is worth every last penny.

In The End
I've read of people using power conditioners complaining that it has made their systems sound closed and constrained. For me, this wasn't what I've found. I suspect those that have experienced that issue may have used a power conditioner that wasn't properly sized for their system. In picking a power conditioner you must size it properly or you will end up with a constrained sound. Much like if you were to put an 18 gauge power cord on a Krell amp. It may work but it won't sound very good.

The gains in clarity, focus and reduced noise floor after the installation of the Balanced Power Technology BP-2 were quite dramatic. This cured my system of the background noises (no matter how low they were) it suffered from. For me and my system, the transformation (and yes it was a transformation) was quite stunning. I now know how proper power conditioning is supposed to sound. I don't think I'll be doing any DIY power conditioning anytime in the near future, especially after hearing the BPT. In fact, I think I'll likely be spending some more money with Chris in the near future for my Home Theatre. The BPT gear is that good.

Another reason I decided to invest in a BPT is that over the years I've had several pieces of equipment give up the ghost and let all the smoke out. I can't say with absolute certainty that this was due to excessively poor power quality but then again….I can't say it wasn't either. I've had a myriad of power supply cap and diode failures in old and somewhat newer gear. This gets to be a pain in the arse. Sure, I repair my own gear but for those who don't weald a soldering iron, this can be costly.

I've read about peoples experiences with transformer based power conditioning. On occasion people have mentioned that the transformer based units they have been using were noisy. I can't speak to those units but I can definitively say that the BP-2 is dead quiet. I get zero noise from its transformer unless I literally mash my ear against the units case.

So, if you are looking to clean up your power, that or if you have some pesky noise like I did, look no further than Balanced Power Technologies. Chris even has a 30 day money back guarantee on his products. That takes all the risk out of buying blind. Just remember, if you run tons of gear that draws lots of current, don't try to cheap out and do with conditioner rated below your total power draw. It won't work... well.

One final thought. Those of you who think that just because you live close to a power plant or you don't have industry between you and the local utility, think again. I live three miles and four hundred cows from the local power plant and my power sucks. You will never know how bad your power is until you install something like the BPT power conditioner. I highly recommend trying one. You won't regret it.

My Ratings
This is going to be a tough one. The reason I say that is, our traditional rating system really doesn't work for a piece of equipment that by design, shouldn't change the tonality of your system. The only thing power conditioning should do is clean up your power and reduce the overall noise floor of your system. It should never get in the way of your sound causing it feel constrained. In such, I've replaced most of the usual categories in favor of new ones tailored to fit a power conditioner.

Please keep in mind this rating system is used to compare the BP-2 power conditioner against absolute perfection, or money no object power conditioner. If you see what you think may be a low(ish) score, it's because there are conditioners that are even more refined but consequently cost considerably more. To top that off, if I assign 5's across the board, I've just painted myself into a corner leaving no room for those ‘ultimate' conditioners. You won't see me handing out many 5's. In turn, I feel I need to leave room in the ratings system to accommodate those conditioners.

Manufacturers' Reply
BPT would like to thank Scott Faller for his enthusiastic report on our BP-2. His personal experience will hopefully encourage audio and video enthusiasts to investigate the benefits of using low noise AC power. While dramatically improving sound and picture quality are often the most noted benefits, reductions in equipment failure or repairs caused by power surges and especially transient spikes may be the most beneficial--at least to your wallet. I encourage anyone that has not already added a quality power conditioning product to their audio or video set-up, do so before purchasing any more equipment or accessories. You will never know just how good your current set-up can perform until you power it with clean AC.

Chris Hoff
Owner/Designer
Balanced Power Technologies

Specifications
Type: Electrical isolation transformer

Input Voltage: 120v

Output voltage: 120v

Duplex Receptacles: 5

Ampere Rating: 15 Amperes

Price as tested: $1199 (base unit), $85 each for Oyaide outlets, $300 for the EP2000 filter, $75 for the machined aluminum faceplate

Company Information
Balanced Power Technologies, LLC
708 Wheatfield Ridge Ct.
Defiance, MO 63341

Voice: (314) 265-1095
E-mail contact@b-p-t.com
Website http://www.b-p-t.com