As its review stated, Chris Hoff's BPT BP-2+ had come bloody close to my reference power line conditioner - Lloyd Walker's entirely passive but sonically mondo active Velocitor. Feeling duly challenged for a fistful of mano-i-mano in the wake of said writeup, Chris slyly inquired. Was I up for taking his forthcoming no-holds-barred effort for a spin? He was convinced it might best the Velocitor and certain other contenders to the throne. [Unfortunately, I didn't happen to have any of those in-house, safe for the new $3,800 Audio Magic Eclipse which thus shall make a brief appearance here.] The new Balanced Power Technologies conditioner in question was the best product Chris knew how to make. He'd thrown every fair, fairy and wicked trick in the book at it. By implication, it meant that this monster was now ready to battle anything and everyone like a mean and lock-jaw'd pit bull. Was I gonna chicken out when being thrown such a glove? It's that most flagrant of all male pastimes: Braggadocio. I can burp louder than you, pee farther and spit higher! Especially when this guy had the raw nerve to challenge my personal pride and joy, carefully hand-picked from quite the crop of worthy contenders. No way, pollo-san. Bring it on. I e-mailed back said notice with blustery confidence - while quietly admitting to myself that I couldn't be entirely certain what the hell I was about to get myself into. That's how it goes with pissing contests. Drink as much as your bladder can hold, then hope the other fella has a sudden bout of gall stone.


To level the playing field, Sr Hoff included a personal Acoustic Dreams platform whence to isolate his BP-3.5 from floor-borne vibration on, in like fashion to the Velocitor whose performance, I kid you not, noticeably improves when properly elevated and bedded not on fluffy Egyptian down but rock-hard butcher block maple, something the very practical and inventive Mr. Walker also employs for his conditioner's casing. Wood, ya know? Hoff also included three Stillpoints with risers, and three Acoustic Dream DeadBalls to use as alternate means of decoupling his baby.


Baby? Elephant brood more like it. Schlepping his 80 lbs heavy BP-3.5 into position atop said shelf -- outfitted as this herniatic beast was with adjustable-tip cones of fiercely pointy ends, to supposedly rest smartly in the included spike protector discs to not disfigure Chris' beautiful wooden platform with multiple pits and gauges -- was a trip and a half. While remembering a half-dozen colorful Germanic curses like Schweinehund and Arschkram, I eventually managed. Screwing one removable tip into a cone at a time while attempting to maintain balance on the three-footed platform, I hoisted the BP-3.5's respective corners to gain access to each cone, twitching to twirl the little pinprick tips into place with the other hand. I was, you see, honor-bound to reward Mr. Hoff's extra effort of including this platform. The whole point of this exercise was to compare apples against apples, since I use my Velocitor on its Valid-Point'd optional (but not really optional) platform. And while by now I felt more like jittery apple jelly than a crisp and tart Granny Smith, stubbornness outwitted gravity. The BP-3.5 ended up perching securely on its solid and spiked outlook, squatting in very elegant silver livery in the Velocitor's usual place of work [see below to left of Grand Prix Audio Monaco stand].




Fitted in the self-same case as the BP-2, albeit this time in the optional though upcharge-free stainless steel finish, the BP-3.5's secret weapon is a custom Plitron transformer. Its 2400VA continuous duty make for not only obscene size and heft, with hand-trimmed secondaries to assure perfect matching of the phase-split +/-60V AC legs and thereby maximize balanced power's modus operandi, the phase cancellation of noise riding atop the power distribution sine wave when its +/- components are recombined. No, the coup-de-grace is a nouveau combination of two Plitron exclusives: LoNo and NBT. While you could be accused of reading nothing-but-tuff into the second acronym -- low noise for the former was child's play -- it in fact stands for Narrow-Bandwidth-Technology.

In Plitron's own words, NBT reduces line distortion within isolation or power transformers by restricting electromagnetic energy to a very narrow frequency pass band. This effectively attenuates higher harmonic and spike distortions which fall outside the narrow range of the transformer's low-pass filter. NBT is based on an increase of internal series inductance, reduction in primary to secondary capacitance and phase cancellation, the latter obtained by connecting a bifilared control winding in contraposition through a capacitor. At low frequencies, the capacitor acts as an open switch to allow the 50/60Hz power frequency to freely cross the transformer. At high frequencies, the capacitor behaves as a closed switch, with the magnetic flux of the two windings canceling each other for full deletion of high frequency signals. Series inductance and capacitor values fix the corner frequency of the transformer's passing bandwidth. Harmonic artefacts of 50/ 60Hz sine wave distortion are common up to 10kHz, above which switching transients from rectifiers and motor drives enter the picture.


At frequencies above 50kHz, strong HF signals from radio, TV and computers are superimposed on the line to appear across the primary winding of a transformer. At frequencies above 1MHz, noise is mostly common mode which refers to both hot and neutral containing an equal amount of amplitude and phase distortion. For frequencies below 1MHz, the major component of the noise is typically differential mode where the noise on both legs' amplitudes is equal but their phase is reversed. Differential mode noise generates a real noise voltage difference between line and neutral. NBT is said to resolve both differential and common mode noise most effectively. As Plitron's graph above shows, their NBT transformer [fat black line = D] offers both the steepest and most drastic (70dB) rate of attenuation, compared to standard toroids [green = A], regular balanced toroids with bifilar center-tap [thin black line = B] or even a standard toroid preceded by an external filter [yellow = C].


BPT's BP-3.5 is unique in using NBT in a fully balanced configuration. Hoff's original NBT conditioner was restricted to the standard toroids available at the time. It caused two of his customers to confide to me that NBT looked perhaps good on paper but couldn't hold a candle to Hoff's better Balanced Power units - like the BP-2 I'd already reviewed. The brand-new 3.5 Signature is balanced power plus NBT. It also uses liberal applications of Stillpoint's ERS stealth cloth wound around wire leads and glued to the Auricap filter capacitors that connect across each of the five duplexes. There's a thick damping sheet material which lines all sides of the already very thick cover and the transformer's underside, as well as a completely encapsulated HF filter which precedes the transformer, and a massive sleeve shielding the critical transformer/outlet-bank flying lead. Solid silver low-gauge distribution rails, expert solder joints and a nearly maniacal concern over detail execution complete the innards of this device.



Inspecting these innards, I was convinced beyond a pale doubt that Chris Hoff's battle ax was honed as lethal to an edge as potent Gimli's, fighting dwarf of Middle-Earth's Fellowship of the Ring. Outside the massive hardware arsenal embedded inside its attractive case, the detail touches of the Signature were of the sort only an obsessive/compulsive audiophile would dream up at 2:00 in the morning - not a regular manufacturer intent on convenient production runs who'd throw a vein-poppin' fit at having to contend with hand-wrapping wires and Faraday cages with "Voodoo" sheathing. Put differently, this BPT flagship offering screamed about as tweaked-to-the-hilt in its balanced power arena as the Velocitor represents in its passive quantum resonance control category. If there was to be any imbalance in this showing, it'd arise from the BPT's 10 versus Walker's 6 outlets, the former's on-board surge/spike protection and a small price differential of $2,495 versus $2,695 - features which could sway prospective buyers, of elaborate systems and thunderstorm-prone locales. As a 20-ampere unit, the balanced power unit came outfitted with BPT's shielded 9-gauge Litz cord. Terminated with the squared-off 20-amp IEC plug that won't fit the ubiquitous 15-amp power inlets, a 6-foot length with FIM jack was included in the $2.5K retail unlike the "cordless" Velocitor.


Also included were four steel balls which can take the place of the removable tips of the isolator cones, should the BP-3.5 Sig end up on a hard surface you don't want to mar with 20 lbs each pressing down on four very sharp steel points. To assure that I hadn't overlooked any invisible features of this super-buff champion, I sent Mr. Hoff the technical descriptions above with a request to fill in any blanks. Here's what he added:


"The dampening sheets on the case and filter are a new three-layer design that, as you can tell by tapping on the unit -- thud-thud -- work quite well. [That was a bit of understatement on the designer's part. It works far better than "quite well".] The NBT/LoNo transformer sports a 2-layer magnetic shield around its circumference plus a double-layer of ERS cloth for maximum EMI attenuation. Ditto for the AC outlets and HC filter which are also covered in ERS cloth. The other new addition to our noise-killing arsenal is the custom Z-Sleeve from ZCable, used between the balanced isolation transformer and the AC outlets. I heard about these little beauties and tried a few in my reference system, on interconnects, speaker cables and power cords. I was so impressed that I asked Mark Hampton, proprietor of ZCable, if I could have a custom Z-Sleeve manufactured to be used inside my units. Mark obliged with some prototypes and we finalized the design specifically for BPT.


The Z-Sleeves are not ferrite or resonance-control based, but designed rather to approximate a Zero Gauss Chamber. The tube creates an internal null area that completely obliterates EMI contamination. The Z-Sleeve further lowers the noise floor to allow for higher resolution and increased dynamics. Unlike most of the resonance-type filters, the Z-Sleeve does not affect tonal balance to leave the music unharmed while stripping away only distortion components*. Another extra in our flagship Signature effort is the cryogenic treatment, by Cryogenics International. for the Hubbell isolated ground hospital grade and GFCI outlets. For the 3.5, we also cryo our 10-gauge, 99.99% pure silver wire."


Hoff's explanatory e-mail merely compounded my prior impressions. The BP-3.5's designer had incorporated every possible trick of the trade - except to adorn his statement piece with statement pricing. $2,495 for this level of tweaked-out quality, make no mistake, is not what any sane person should rightfully expect. As for sonics? Read on and watch your wallet get all unreasonably twitchy with lust...


*[Lest you assume this was stating the blatantly obvious, remember that many power conditioner do, in fact, strip away not just noise but musically vital components as well. Shares one reader in more detail in our letters/feedback section:
"... I write to report that influenced by your review of Balanced Power Technology's maxed out BP-2 model, I replaced my Richard Gray 400s with Chris Hoff's product. I was fortunate to sell my Richard Gray as soon as I listed it on audiogon. This left me running my system (Wadia 860, Atma Sphere M-60's, Merlin VSMs, Quattro Fil, Cardas Golden Reference speaker cables and Magnan Signature power cord) out of the wall for the first time in about a year and a half. I was surprised and disappointed to find that dynamics significantly increased without the 400s ..."]