What is a Quantum Purifier, and why should you even give a hoot? I hesitate to describe them as tweaks, because that tends to marginalize any add-on product. With most tweaks, the lingering implication is that at best they may be expected to incrementally improve the sound of one's system. That is not the case with the Purifier, which embodies an exciting new technology that with a bit of commercial luck may just become as ubiquitous in high-end audio systems as are resistors and capacitors.

The Purifiers are the brainchild of Jack Bybee, a physicist who was deeply involved in the development of a series of esoteric wire and power purification technologies to reduce the noise floor aboard nuclear subs and thereby improve sonar performance. Jack says that many of the military applications of this technology are still classified, however, continuing research has led Jack Bybee to develop solutions specific to audio and video circuits.

Bybee's current product line supercedes previously released products. The Quantum Purifiers are primarily intended to be installed internally in any active device or speaker. More information on specific applications is to be found on Bybee's web site.

Technical Details

As a very basic intro it should be stated that signal conduction in all electronic circuits is based on the movement of electrons through the crystal lattice of conductor materials. While the signal does indeed propagate at the speed of light, individual electron motion is extremely slow and ponderous. Ultimately, the noise floor of any electronic circuit is due to the quantum nature of the electron and its interaction with the crystal lattice through which it moves. Several types of quantum noise have been identified. Thermal and shot noise were discovered by Schottky in 1918. Random thermal motion of the charge carriers produces a small fluctuating noise potential, whose power is uniform over frequency - so called white noise. Thermal noise places an ultimate limit upon signal to noise performance in real circuits, which cannot be improved upon without cooling the circuit. Shot noise occurs in certain devices (e.g., vacuum tubes) due to random fluctuations in current and its spectrum is also white in character. In contrast, thermal noise is usually not an issue with solid-state devices. However, for many solid-state circuit elements (e.g., MOSFET), the noise floor is dominated by frequency dependent noise, often referred to as 1/f noise. Its spectral density increases as the inverse of frequency, just like pink noise. But unlike pink noise which is broadband, 1/f noise is typically confined to under 2 kHz.

The key point is that 1/f noise behaves like the musical spectrum. Its envelope mimics that of the musical signal. Recent research indicates that perceptually such noise blends in very well with the music. Once buried within the music, it is reasonable to speculate that 1/f noise defuses image outlines and adulterates harmonic textures. After all, the sonic benefits of the Purifier are exactly in these areas. Thermal noise, on the other hand, is audible but does not correlate with the music. To put it into perspective, let me use the analogy of vinyl ticks and pops. Yes, they are quite audible, but they are resolved as distinct from the music. And no, they don't bother me for the same reason that audience noises are part of the concert hall experience. I have been able to enjoy music at home through some pretty noisy tube-based systems, which means that conventional signal to noise ratio does not tell the whole story. The fact that 1/f noise dominates in many solid-state devices holds a vital clue that may explain, for example, some of the perceived sonic differences between tubes and transistors.

The basic premise of the Bybee's audio devices is that 1/f noise detracts from the listening experience: reduce 1/f noise and you improve the sound. The Purifier uses a combination of rare earth metal oxides in a ceramic form to absorb and dampen 1/f noise. The ceramic surrounds a low-value resistance (about 0.1 ohm). I asked Jack Bybee to provide me with a brief explanation of the physics and engineering taking place in the Quantum Purifier, without violating proprietary or classified secrets. The bottom line, as Bybee states, it is that "when developing the technology we did not fully understand why certain metal oxides absorb or damp specific frequencies and to the best of my knowledge we still do not." However, as is the case with audio cable and interconnect, a fully understood theoretical basis is not necessary to enjoy the benefits of the technology.

The purifiers are non-reactive and present a stable, low-impedance load. All devices are now cryogenically treated, which is said to improve performance. The outer layer of the purifier is Teflon coated.

The Experiment

When I agreed to the review, I made it clear to Jack Bybee that the context for the evaluation would be my BassZilla loudspeaker, Lowther version. First of all, I'm very familiar with these speakers, which would make them a very sensitive test bed. And second, the crossover network is mounted externally, so that it's an easy matter to access the driver connections. As a general rule, Bybee has found the best results from connecting the Purifier right at the driver terminal, so that it is in series with the voice coil without any intervening components. I followed this recommendation by soldering a small Purifier adjacent to the positive terminal of each driver. Because of the BassZilla's high sensitivity, Jack thought that the small Purifiers ought to work for both the woofer and full range. He normally recommends the large Purifier for woofers, but since I typically use low-power SE tube amplification, he felt comfortable with the smaller devices that require less of a break in period. By the way, I now have the large purifiers on hand as well for additional testing.

The Sound

I installed the Purifiers in two stages, so that I could evaluate the cumulative effect of multiple devices. In the first stage, I added Purifiers to the Lowther DX4 drivers. Because the effect was so dramatic, even after a minimal break in period, I hastened to treat the woofers that same afternoon. Again the effect was clearly audible in the range covered by the woofers.

The first impression was of heightened coherence. The various threads making up musical passages snapped into greater focus. There was simply less confusion about the placement of individual instruments within the soundstage. Image outlines became more palpable, and the depth perspective increased. The net effect was that soundstage transparency was propelled several notches forward. It became much easier to peer into the inner recesses of the soundstage and to gauge the relative placement of various instruments. If I may be permitted a melodramatic touch, it felt as if the Quantum Purifiers threw a giant search light onto the soundstage, allowing for exquisite spatial detail and depth layering.

My attention was next drawn to transient detail. Transients were, in general, better defined. The attack portion became more incisive, while the decay was easier to follow into the noise floor of the recording. This made for an increased sense of speed and control. Low-level detail retrieval also benefited. At no time did I feel that the Purifiers added anything artificial to the sound. The increased detail was not the result of any cheap tricks, but a natural outgrowth of the Purifier's ability to clean up the sound. In the category of cheap tricks, I have in mind hot sounding, etched Kevlar and metal dome tweeters, though to be blunt about it, that description is a perfect match for almost all of these tweeters. I listen to such tweeters for the same reason I'm fascinated by train wrecks. Audiophiles, on the other hand, have voted with their check books for the privilege of indulging in razor-sharp treble. The Purifiers are fast, but they don't loose treble control. I can imagine that a system with a hot treble range might actually sound a bit more natural with the Purifiers in place. If that sounds disappointing, I guess the Purifiers are not for you.

Instrumental timbre also got the Windex treatment. Harmonic textures increased in purity as if a layer of dirt was washed away. In the upper midrange, where the ear is most sensitive, overtones bloomed with a bit more sheen than before. Dynamic nuances were also a bit more convincing. The music's emotional power was allowed greater freedom of expression. Finally, the upper bass and lower midrange sounded better integrated with the core of the midrange. This gets us back to the feeling of coherency that the Purifiers are so good at preserving. I suppose that the degree to which this attribute is manifested may be speaker dependent. In the case of the BassZilla, which is about giving full-range drivers freedom of expression, coherency is already high. In the case of multi-way speakers, where the signal is chopped up and fed to various drivers with the hope of somehow reconstituting the sound at the listening position, the situation is less clear. But my guess is that even in the case of three and four-way systems that the Purifiers should help pull the sound together.

Also provided by Jack Bybee, much later in the review process, was a pair of the interconnect purifiers (with male/female RCA connectors) that our Wayne Donnelly raved about previously. These were connected at the output of the preamplifier. Their effect was very similar to that of the speaker installed purifiers and highlights the cumulative benefit of these devices.

Conclusion

Once in a life time there comes along a technology that breaks new ground and is easily worth its weight in gold. Such is the case with the Bybee Quantum Purifier. To put it into perspective, imagine the following scenario. Money is no object and you have the opportunity to purchase $20,000 worth of the finest cable/interconnect. Let me make this perfectly clear: $320 worth of Purifiers will make for a far greater sonic improvement in your system than would all of that cable. In hindsight, cable is a band aid - the Purifier the cure.

Based on my experience with the interconnect purifier, their sonic effect is clearly cumulative with additional devices upstream from the speakers. The magnitude of purity and focus engendered by this device would typically only be the result of a major system upgrade. Before you throw a lot of money at your system, give the Purifiers an audition. Go ahead, give your audio system the Windex treatment. If there ever was a no-brainer recommendation, the Bybee Quantum Purifier is it. I can't imagine listening to my system without them.

Manufacturer's Reply

Dear Dick,

I am writing to thank you for your wonderful review of my Quantum Purifiers. I greatly appreciate your generous praise, and I appreciate the careful methodology that led to your conclusions. Beyond that, I am particularly impressed with your lucid explanation of 1/f noise, its effect on the musical signal, and how the Quantum Purifier addresses that problem. Your explanation is much more understandable than anything I have ever come up with. It's very nice to have scientific knowledge and good writing come together.

To clear up one small point, the RCA plug-in devices you mention are not the same as the interconnect purifiers that Wayne Donnelly reviewed. Although they look identical, the ones you received were a special pair that I made up to show the efficacy of treating the ground as well as the positive side of a circuit. I sent them to you to give you an idea of the value of internal modifications for electronics, without requiring you to start surgically altering your electronic components.

Should you have any interest in continuing your exploration of the Quantum Purifier's effects on AC power, analog and digital circuits, please let me know. I would very much value your comments in that area.

Best regards,

Jack Bybee