I purchased an Onkyo Integra series P-303 preamplifier way back in the 1980s. It came with a beautiful wood cabinet and looked great from the outside. But inside is where the real beauty hid: it came fully shielded with an anti-magnetic material called Mu-metal. Mu-metal (aka mumetal) is used primarily shield against low-intensity magnetic fields where the highest attenuation, highest initial permeability µ (Mu) and highest shielding efficiency are desired. Low-level audio signals such as those found in pre-amplifiers and low-output moving-coil phono cartridge (pre-pre) amplifiers are a perfect places for the application of this technology. Seeing it in the P-303 reassured me that engineers - when given the proper budget and license - would apply appropriate high-technology to a design.
|Onkyo Integra P-303 and Internal Mu-Metal Shielding, Circa 1982|
Blah, blah, blah. These are features many other power conditioner manufacturers have already; no surprises here in the choices of fundamental building blocks. But there was something different about this particular conditioner that made the music come alive.
|BPT Power Conditioner|
|Cover Off - Stunning Transformer|
Fascinated by the size of the huge toroid transformer, I initially overlooked something: the prolific use of the Stillpoints ERS stealth cloth lining the chassis and most of the components. I knew how much a 20-amp 120V low-leakage isolation transformer costs so I was initially impressed by its appearance inside of this unit, so much so that I initially ignored the gray cloth. With this cloth appearing almost everywhere, it gave the unit a really "clean" appearance matching the class engraved front panel.
Continuing with the inspection, one can see the care taken to carefully solder a solid-silver hot, neutral, and ground bus to the four 20A hospital-grade outlets and the one 20A GFI outlet. With the presence of a GFI outlet, this toroid is most certainly a balanced output secondary (60V-CT-60V) as opposed to what I originally anticipated it to be, a more conventional single-ended (autoformer or 120V-neutral) transformer design (a definite step up here). Previous models used a custom designed Plitron low-noise narrow-bandwidth toroid and I suspect that this unit is no different, possibly even an improved version. Standard RF capacitor filtering is used at each outlet and the values concealed behind heat-shrink tubing. Again notice the abundant presence of the Stillpoints cloth on the outlets. Previous models used this cloth liberally applied on the outside of these capacitors and the heat-shrink tubing now holds this cloth securely in place.
|Solid Silver Electrical Bus and RF Suppression Capacitors|
|BPT Cover Treatment|
|Copper Band Around the Transformer|
One last item not to overlook is the RF/surge capacitor used at the switch.
|1.0uF/250VAC Surge Capacitor|
With this much attention to detail, it should sound really good, right? In a word, YES! An emphatic and unreserved YES! Like a vacuum cleaner, this unit removes the "grunge" from the noise floor in all of your gear and improves overall dynamics. Digital sources sounded less edgy and video sources were hugely more three-dimensional. My friend's old power conditioner just didn't permit any of the potential his electronics and video systems to shine through. In my friend's own words, "I can listen to this system now for prolonged periods of time where before it became fatiguing to me after about 30 minutes..."
Yes, listening to streaming digital for prolonged timeframes can be fatiguing to a sensitive ear but this power conditioner helps resolve some of this problem. While my friend's system developed issues with the music server (a stuck CD in the drive) and I was unable to thoroughly evaluate this power conditioner's full potential, I can say that for the few hours we spent with it, I was impressed. Swapping out power cords to his preamp from various manufacturers easily revealed differences between them, something most people find difficult or even impossible to discern. I suspect that the weak link in the chain in this case is inadequate power conditioning and not the proverbial "snake oil."
The Bottom Line
Is it worth the money? IMHO, without a doubt. I have found that cleaning up noisy power issues can have as big an effect on your system as changing the speakers. If you live near the end of an electrical service corridor as I do, far from the substation, your electricity is about as "dirty" as it can get. Everything switching on-off, every motor running, every computer power supply between you and the substation appears on YOUR outlets and this noise is cumulative.
Filtering noise out with modest design approaches just isn't worth the money since to do so properly takes a multi-tiered technique such as the ones used by BPT. Attenuating surge is a whole different ballgame than eliminating noise but surge suppression is what most people focus on - and incorrectly I may add. Protecting your gear is important, enough said. But providing clean power is not the same thing and surge protection does little or nothing to improve the sound of your system.
I have found that when spending thousands on a preamp, if you do not spend thousands on proper power conditioning, you have literally wasted your money on that preamp. It's sort of like running watered-down low-octane gasoline in a top-fuel dragster: it just doesn't make sense (GIGO and the "weakest link in the chain" principles apply here).
So if you are ready to step up to higher fidelity, give the BPT a spin. I believe they still offer a 30-day money-back return policy so these folks are pretty sure you will be impressed by their work. I'm suspect that it will find a place in your evolving system.
708 Wheatfield Ridge Ct.
Defiance, MO 63341
Phone: (314) 265-1095
Yours for higher fidelity,
I do not use ads in this blog to help support my efforts. If you like what you are reading, please remember to reciprocate by purchasing one of my eBooks or through a PayPal donation, My newest title is called Where, oh Where did the Star of Bethlehem Go? It’s an astronomer’s look at what this celestial object may have been, who the "Wise Men" were, and where they came from. Written in an investigative journalism style (like that of the Discovery Channel), it targets one star that has never been considered before and builds a solid case for its candidacy.
Copyright © 2015 by Philip Rastocny. All rights reserved.