Silence in the Electricity Network
Every HiFi enthusiast has a similar experience: You sit relaxed in front of the stereo system, but what you heard so nicely yesterday just refuses to repeat itself. Stress, missing details, the soundstage is not so wide as you remembered. As an informed Audiophile, you are aware of the reason: It is not dependent on my mood. The best components cannot sound their best when the neighbours won't let them perform. The biggest culprit of poor sound quality is often electrical noise in the electricity supply. The electrical noise might be in your electrical line, or in your general neighbourhood. Against such network noise, some people install electrical filters in parallel or in series. But such filters can also cause much problems: the dynamics will suffer with the additional resistance introduced by such filters. The sound might be cleaner, but less lively.
According to James Soh from Plixir, the problem is caused by the design of such passive filters. If you divert the damaging frequencies over 50 Hertz with capacitors to the Earth, this can disrupt the electrical noise removal within the system. The Plixir is called a "Power Conditioner" which is essentially a separation transformer which doesn't regenerate the electricity. The Plixir contains expensive XQ-Core-Ring Transformers made by Noratel. You can sense its quality from its weight. The BAC 1500 weighs 25kg. The small BAC 150 already weighs 4.5kg. The transformers are of low resistance, says James Soh, and this has the advantage of improving the dynamics, while leaving high frequency noise behind.
Another feature is that the Plixirs work symetrically, working 2x 115V. This has the advantage that you don't have to worry about the equipment being out of phase. (Except for the power conditioner which very practically, has the phase marked on it.) The Plixir transformers also reduce low frequency rumble.
I was curious by this design concept. When I found out that Reinhold Schaeffer, whose b-Fly products I value very much, deals with the Singapore-manufactured Plixirs, I was assured of their quality. With three models from the Elite range - the BACs 150, 400 and 1500 - we could test out a wide range of possible configurations for using the power conditioners. The model numbers indicate the maximum power capacity of each model. In normal use, you should however keep some power reserve and not use up all the capacity so as not to risk overburdening the equipment. Mr Schaeffer recommends that you choose a model that has at least 50% more power capacity than is required by all the components you intend to plug into the conditioner. For the BAC 150, you should only attach source components, DAC or preamps which altogether do not require more than 100W of power. For the BAC 400, you can plug in small amplifiers, and the BAC 1500 can handle more powerful amplifiers.
I normally plug my system into the wall socket. Even though it is a dedicated socket for my system, it sounds pretty poor. The sharp, dull, spotty sound improved noticeably when I plugged in my CD transport into the Plixir. The background was quieter, the instruments were more three dimensional, and the high frequencies more relaxed. After attaching the DAC and preamp, the violins lost any residual harshness and the spaciousness increased more significantly. This result didn't surprise me because with their low power requirements, any small disturbances in the power supply can be fatal to the sound.
With the power amp connected to the BAC 1500, everything sounds even cleaner. The improvement is not as big as before, but it is noticeably there. And after testing with the full orchestra playing its most demanding pieces, I did not notice any dynamic limitations. The Plixirs work so effectively and gently that I feel it brings better results than the PS Audio P10 power conditioner, a device which I think is already very good and transparent. With the BAC 400, source components and DACs produce clearer and more relaxed sound.
Conclusion - Every power situation is different and every system is different. So you have to experiment with power conditioners. With the Plixirs, I am sure that it will bring improvements to any system. When you need a passive solution, I would recommend the Plixirs. I would use them myself.
by Uwe Steiner