REVIEW: BPT (Balanced Power Technologies) BP-3 Balanced Power Isolator
Mar 4, 2002 at 9:13 AM Thread Starter Post #1 of 22
[size=medium]BPT (Balanced Power Technologies) BP-3 Balanced Power Isolator:[/size]
[size=small]An Entire System Upgrade In A Very Heavy Box[/size]

  1. Description: Dual-transformer (one 1000VA and one 300VA) balanced power isolator. The 1000VA transformer is rated at 8.0+ amps continuous. The 300VA transformer is rated at 2.5 amps continuous.
  2. Dimensions: 12"W by 4.5"H by 12"D
  3. Manufacturer: Balanced Power Technologies (BPT). Telephone: (314) 603-1483. Web: http://www.b-p-t.com
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The power that comes from our wall outlets courses through our audio systems; but it hasn't been until the last ten years or so that the conditioning of wall power, just before it's fed into the audio system, has become a widespread practice. In fact, I worked in a high-end hi-fi store back in the late 80's, and not a single component on display was plugged into any sort of power conditioner, nor did we sell any powerline products. Considering how much opportunity there is for noise and contamination to get introduced into the who-knows-how-many-feet of conduit that delivers that power to our gear, it seems surprising to me that it took this long for the onset of this practice's popularity in the always obsessive, nitpicky world of hi-fi.

After I put together my first dedicated headphone system, I noticed some very obvious power-related noise. Whenever my refrigerator or sump pump kicked in... Click! Pop! So I decided to get a Price Wheeler Brick Wall line conditioner / surge filter. Not only did the clicks and pops disappear, but the noise floor of my rig was lowered, and my rig's retrieval of fine details improved. I initially approached the power conditioning game with mild skepticism, so I was actually somewhat surprised by the sonic benefits.

Being a typical audio enthusiast type, though, one of the first thoughts that naturally came to mind was that I wanted to take it at least a step further. Further research led me to conclude that the most practical next step would be complete power regeneration or balanced power. Complete power regeneration (like PS Audio's PowerPlants) looked very compelling, but was out of my desired budget. Balanced power looked like it would be out of reach of what I had budgeted too -- until I read about BPT at Audio Asylum.

First of all, what is balanced power? Wall power in the U.S. is typically 120 volts, delivered 120 volts hot-to-ground, zero volts neutral-to-ground. A balanced power isolator is usually a toroidal transformer with a center tap that takes in the standard 120 volts as typically delivered, and reconfigures and delivers it to your components as 60 volts hot-to-ground, and 60 volts neutral-to-ground, inversely phased (thus, still looking like 120 volts to your gear). What's the benefit? The most obvious is something called common mode rejection -- or phase cancellation -- of noise. Noise and reactive current carried on one leg is now carried in inverse phase on the other leg, and so they sum to zero (essentially canceling each other out) at ground (the center tap). Whereas most power filters are particularly good at reducing higher frequency (MHz-level) noise, balanced power, through commode rejection, can achieve noise and reduction across a much wider bandwidth, including the audible band. NOTE: For a far more detailed and able technical discourse on balanced power, I highly recommend checking out Martin Glasband's writings (as well as his products) at Equi=Tech's web site.

Like power regeneration units, balanced power isolators have generally been quite expensive, with prices usually starting over US$1,000.00 -- that is, until Chris Hoff and his company, BPT (Balanced Power Technologies), came along to buck the trend. Starting off BPT's line of balanced power isolators is a little number called the BP-Jr. Designed to provide up to 300VA, the BP-Jr. can be used to power source components, preamps, or even most entire dedicated headphone hi-fi rigs (source and headphone amp). At US$299.00, I don't know of any lower priced balanced power unit.

But I wanted more. I wanted to be able to totally separate my components, to reduce as much as possible the possibility that my digital source component and headphone amp would interact with one another through their power supplies. I considered two BP-Jr.'s for this, but decided instead to go for BPT's model BP-3, which contains both a 300VA isolation transformer (essentially a BP-Jr.) and a totally separate, much bigger 1000VA isolation transformer, all in a single chassis. Three duplex outlets are tied to the 1000VA transformer, and one duplex outlet is connected to the 300VA transformer, for a total of eight individual receptacles.

I also had my BP-3 tricked out at BPT with brass feet, hospital grade receptacles (and each of the three pairs of receptacles tapped in to the 1000VA transformer are additionally isolated from one another), upgraded capacitors, additional RFI/EMI filtering, a C-7 power cord upgrade, and extra chassis resonance damping. The base BP-3 goes for US$ 699.00, and the options I added will run the bill up another US$ 200.00 or so.


Setting Up The Current-Inhaling Heavyweight

My first impression of the BP-3 was formed as I carried the unopened shipping box from my porch to my desk -- it's heavy. I haven't put it on a scale, but I'd guess it's at least 30 or 35 pounds heavy. My Sony SCD-C333ES weighs almost 25 pounds, and the BP-3 definitely feels the heftier of the two.

It was packed fairly well, but, if they haven't already started doing so, I'd definitely suggest that BPT use more foam to protect their heavier models during shipping. Apparently some in-transit impact drove the bottom left-front corner of my BP-3 completely through the thin padding underneath it, and almost completely through the bottom of the outside shipping box. Unfortunately, the impact left that corner of my BP-3 somewhat bent. But, since it seemed to be working fine, I decided that accepting this minor blemish was easier than shipping this behemoth back to BPT for a new chassis.

My first impression of the unit itself was good (save for the aforementioned packing- and shipping-induced blemish). For the relatively low price, I expected it to be simple, and it certainly is that -- not a switch in sight. The formed sheet metal chassis seems strong and durable. Tapping on body of the BP-3 reveals it to be a very solid unit -- even the broad expanse that is the top of it thuds, rather than rings, under my drumming fingers. In terms of its aesthetic appeal...well, it's somewhat attractive in a utilitarian sort of way that shrugs and says, "I was made to hold two heavy transformers, wiring, hospital grade outlets and various other internal components--what else did ya expect?" In other words, the chassis does a durably good job at containing the unit's bits and pieces, but don't expect Krell, Pass Labs, Rowland, PS Audio, or HeadRoom Max fancy shmancy, tank-like chassis construction -- which, given the price, is understandable to me.

One thing that does look like it belongs on a tank is the C-7 power cord upgrade I ordered for my BP-3. This cord is, well, huge, and it's pretty much all conductor, no filler -- 7-AWG hot, 7-AWG neutral, and 6-AWG ground conductors in a shielded design. The conductors are silver-plated, Teflon-insulated copper. There are thicker power cords out there, but not many that I know of have this kind of conductor immensity. I'm sure there are fancier powercord designs available -- in fact I've found a couple I like better than the standalone C-7 I ordered for use with my Max -- but the choking of current is the least of my worries with this cord. My BP-3's C-7 upgrade is a captured cord, but I believe you can now order your BPT units with an IEC jack for power cord changes (an option I wish I asked for, if only to allow further power cord experimenting and tweaking).

Plugging in the BP-3 was a bit of an adventure, but one that the owner's manual fortunately covers. You see, when you plug it in, there's a good chance it'll trip your circuit breaker, as the BP-3, with its big honkin' toroidals, furiously sucks in its first very deep breath of current. For whatever reason, whenever I've had to unplug my BP-3, plugging it back in required two resets in the basement. And getting the circuit to stick required -- as the manual suggests -- unplugging everything else plugged into that circuit. Once started up, and the initial inrush is over, all is well and stable, but that initial startup current draw is what keeps me from ever shutting down my BP-3 on purpose.

If you do not have a dedicated electrical circuit for your rig (which I hope to have soon), I strongly recommend plugging the BPT balanced power isolator into a circuit that does not have dimmer-equipped lighting anywhere on it. Using a dimmer-dimmed light plugged into the same circuit as the BP-3 can cause its transformers to vibrate and hum quite noticeably. Luckily, this hum does not find its way to the actual signal path, and it goes away immediately after the light is turned off, or turned all the way up.

The BP-3 appears to be well shielded. EMI readings using my NoRad ELF Magnetic Field Meter (Band I MFM) and an AlphaLab TriField Broadband Meter were as low as ambient four to five inches from the BP-3, with maximum readings of approximately 25.5 milligauss when the NoRad was pressed directly against the left side of the unit. AC electric fields (kV/m) around the BP-3 were negligible, as was RFI. Plugging the BP-3 into the Brick Wall slightly increased the Brick Wall's EMI output, but not enough to necessitate relocating the Brick Wall. Given these measurements, I felt comfortable placing the BP-3 anywhere. Ironically, after taking these measurements, I ended up setting the BP-3 down on a wood slab under my desk, well away from any other components anyway (I ran out of desk space).
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My SCD-C333ES SACD/CD player is plugged into the 300VA transformer, and my HeadRoom Max headphone amp is plugged into the 1000VA transformer.


What Clean Power Sounds Like To Me

The long and short of this review is that the BP-3 made itself immediately obvious in my rig in a very good way. I'm not overstating it when I say that the sonic improvements I hear are quite stunning. The first impressions I posted about the BP-3 several months ago remain true today, so you'll find them mixed in below with some new comments and observations that have developed since then.

Unlike many tweaks and system adjustments that you have to listen hard for, the effects of balanced power were instantly apparent in my system. Playing Jeff Buckley's Grace (Columbia CK 57528), which I've heard a bazillion times, was a nice early exhibition of what to expect. Buckley's cover of "Hallelujah" by Leonard Cohen would be hauntingly beautiful on a child's Fisher Price cassette player. On my pre-BP-3 rig, listening to that track felt like I was being sung an intimate secret. After the BP-3, Jeff Buckley and I occupy the same space in my head, his voice breaking cleanly from two-dimensionality, with everything present but the physical sensation of the faint, drawn-out breaths that he punctuates so effectively with in that song.

Obviously, the better the recording, the more information present, and the more effective the results. The Rachmaninoff "Piano Concerto No. 3 in D Minor" SACD (Sony Classical SS 64384), performed by Arcadi Volodos, and conducted by James Levine, is a powerhouse recording to my ears, even if it's not my favorite performance of that piece (from a performance standpoint, I'm partial to Van Cliburn's on Philips CD 456 748-2). On this recording of Volodos, the shape of each note is made even clearer on my balanced-power-conditioned system. Each step of Volodos' rapidly dancing fingers, as choreographed by Rachmaninoff, rings more clearly and true -- and there's some remarkably fast dancing in some passages (for those familiar, think of the beginning of "Finale. Alla breve"). When reproducing piano, some rigs "lose the felt." That is, a piano note is obvious once struck, but the fact that it is initially a felt-covered surface striking string isn't always obvious -- that is, the sometimes very brief softness of attack that precedes the main part of the note can be easily lost. Though I always felt my SCD-C333ES / Max/ HD-600 / ER-4S combo did a great job of conveying well-recorded piano and its many nuances properly, cleaning up the power to both main components has made my rig something of a piano reproducing wizard to my ears.

The BP-3 also seems to have improved my system grounding, quieting it significantly. Prior to the BP-3, I had to "lift" the ground on my Max (the Max has a switch on the back to do this) to get the blackest backdrop I could. Before the BP-3, switching between ground lift and normal ground position was very noticeable (this would likely vary from one Max owner to the next, as it is likely dependent on AC conditions). With the BP-3, not only is there no noticeable difference between the two settings now, but both settings are more quiet than the pre-BP-3 Max with lifted ground.


Summary

When you look at an object in front of you, there are a number of things that tell you it's there in front of you, what the three-dimensional shape of the object is, how its surface might feel if you touch it. One factor is the play of light on the object, and the shading and shadows that result -- and there is a lot of information present in the shading and shadows. A music recording is the same way. There are details that I can't quantify -- some obvious, some minute -- that define the shape and feel of what we're listening to. Even the tiniest details can help tell us how real it is -- details that can unveil the shading that rounds the edges and lifts instruments and voices up so that we feel like we can somehow touch them. This lengthy review is my embarrassingly verbose way of describing what I feel cleaning up the power with the BP-3 has done for my rig -- every voice and instrument, especially in my better recordings, takes on much greater separation and stands out taller and more live against deeper relief.

Results will likely vary from rig to rig, and from place to place. The dirtier your power is in its untreated form, the more dramatic the results will likely be with balanced power. Considering some of the issues I was having with outside power-related noise sneaking into the signal path in the form of obvious clicks and pops, as well as the grounding issues I had, I'd say my pre-treatment power was anything but ideal.

What are some things I would change about the BP-3, or things I wish it came with for the price? Without a doubt, one thing I'd like to see is a soft-start feature that would have the transformers more gently inhale current when initially plugged in. A power switch would also be very convenient, so that those who have to plug it into an out-of-reach outlet don't have to go through the inconvenience of unplugging the unit to turn it off.

I approached the BP-3 as an expensive tweak, but it has so far shown itself to be much more like a key component than a tweak, serving to significantly upgrade my entire rig. If it's a tweak, it's easily the most effective tweak I've tried -- by far. I wonder how much better that fabulous gear I sold back in the 80's might have sounded plugged into something like the Balanced Power Technologies BP-3 -- probably would have helped me sell more gear, eh?


Associated Equipment
  1. Digital Sources: Sony SCD-C333ES SACD/CD player
  2. Headphone Amplifiers: HeadRoom Max (current model); McCormack Micro Integrated Drive Rev. A
  3. Headphones: Sennheiser HD-600, Etymotic ER-4S
  4. Cables: Interconnect: Cardas Neutral Reference, Acoustic Zen Silver Reference. Headphone: Cardas prototype HD-580/600 cable, Stefan AudioArt Equinox for HD-580/600. AC: Acoustic Zen Tsunami, BPT C-7, Tara Labs RSC Air
  5. Miscellaneous: Price Wheeler Brick Wall PW8R15AUD series mode surge filter / power conditioner
 
Mar 4, 2002 at 10:02 AM Post #2 of 22

ai0tron

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Nice review Jude! I definately liked the combination of technical knowledge and subjective listening impressions. Very professionally done.

Hey, when I own my own company Ill probably buy one of these!

I also like Rachmaninoff, I have a recording of he himself playing his 2nd and 3rd piano concertos. From way back in the 20's to the 40's. Its on NAXOS if you dont have it already. The quality is of course, not up to modern standards, but you can still hear the soul of the music.
 
Mar 4, 2002 at 7:18 PM Post #3 of 22

Tuberoller

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Does Chris know you have printed your review Jude?I'm sure he's quite happy that unit has finally been reviewed.LOL!!!He's a cool guy and I like his products .He ships really fast as well and does lots custom work(# of outlets,box dimensions,etc)I even got a BP-2.5 in silver.This is the only conditioner that clearly sounds better than the Monster units.I have tried a few others(tice,etc)and none really "sounded" any better than the Monsters that I have,exept for the BPT units.I have always felt that Power/line conditioners are a key system component and would highly recommend the BPT units,especially if you use tube gear.Btw ,Jude this is the best review I have yet seen on head-fi.I really like the actual EMI measurements.I look forward to the other reviews,thanks.
 
Mar 4, 2002 at 9:53 PM Post #5 of 22

KShaft

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Very nice review. Very articulate.

"A very balanced review...." hehehe get it?

One thing i have to mention,

Now you paid $800 for the unit, with all the upgrades. You mentioned that you were looking into the ps 300 which is probably one of the best you can get(along with hydra and stealth...). For around $900 you can easily find a used ps 300, often for less. I believe the ps 300 also balances the power as well.
Now if you had ordered the jr. this would make more sense, unless you just dont want to buy stuff used. Im just wonderin why you didnt just spend the extra $100 and get the ps 300.

Im debating this myself, but its either the jr. with upgrades or a ps 300. paying $700 is just to close to the ps 300 to not save $200-$300 and wait.

oh yeah dont forget those power ports. id suggest getting some of those (or if you really want to spend the dough some wattgate outlets...) or maybe some hospital grade outlets from your local home depot at least.

thanks again for the review,
k.s.
 
Mar 4, 2002 at 10:13 PM Post #6 of 22

chych

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I don't think the P300 is a balanced power unit, it is a massive power supply/conditioner... the PS "Ultimate outlet" at $300 (BPT Jr Competition) is balanced though, and you supposed to connect that into a PS Power plant...
 
Mar 4, 2002 at 11:46 PM Post #8 of 22

DanG

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The P300 does, in fact, produce balanced power. However, as Jude has explained to me, it isn't balanced as closely as the BPT (or Equi=Tech, I presume) units. This is why it is possible that an upgraded BPT-3 may arguably be better-designed than the P300.

The idea of multiwave seems interesting, though... it would be nice to see a review of the BPT unit against the P300 with multiwave.
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Mar 5, 2002 at 12:58 AM Post #9 of 22

KShaft

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the bpt's main duty is to balance the power. so it might do it better than the ps 300. However, the ps 300 regenerates the power, whereas the bpt merely balances the power given.

big difference. but the price is also different as well.

Jude could power a speaker system with his bpt.

Youd need at least a ps 600 to power that speaker system and that is in excess of $2000 retail.

k.s.
 
Mar 5, 2002 at 4:37 AM Post #11 of 22

BenG

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Tuberoller, you mentioned that you thought the BPTs were the only units that were clearly better than the Monsters...I think a major downfall of the Monsters are current handling, especially with power amps, and this is from direct experience.

I'm curious if the bigger BPTs can really handle power amps without current choking. I'm really interested in the PS Audio Ultimate Outlet, mainly because it's claimed not to be current limited.
 
Mar 5, 2002 at 7:36 PM Post #12 of 22

Chris Hoff

Manufacturer B-P-T (Balanced Power Technologies)
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Great job and many thanks to Jude for his insightful review of our BP-3. Balanced power does indeed lower the noise floor and let's the recording shine through. We have made many changes to our unit since Jude recieved his "custom" BP-3, incorporating many of the upgrades Jude requested for his unit.
The new unit is 18 gauge steel (Jude's was 20 gauge) and is available in a very durable black powder coat or stainless steel, your choice, same price. Each unit has a high current on/off switch and removable C-10 (10 AWG copper/silver/Teflon power cord). Heavy case damping is included, along with surge protection and rubber feet. There are two versions available; standard or Ultra Edition ($100 upgrade). The rear sports 5 duplex 20 amp rated outlets. One duplex outlet is a direct unbalanced 120V AC with a parallel filter to remove incoming RFI, suitable for a power amp. Three duplex outlets are connected to the 1000VA isolation transformer and provide 8+ amps of isolated balanced power with GFCI ptotection and a separate RFI filter network on each duplex. The last duplex is connected to the 300VA isolation transformer and provides 2.5 amps of isolated balanced power with GFCI protection and a separate RFI filter. The Ultra Edition upgrade includes all hospital grade outlets and a C-7 (7 AWG silver/copper/Teflon with heavier AC plug) power cord. There are a couple other options available that can be found on our website.
Again, much thanks to Jude and a reminder that BPT offers Head-fi members a 10% discount.
 
Mar 6, 2002 at 4:29 AM Post #14 of 22

DanG

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I've heard that using any kind of line conditioner can make for a cleaner picture. I'll let someone more knowledgeable than I am say whether a balanced-power unit or power-regenerating unit can provide additional benefits.
 

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