Bella Sound Kaula 2 and Kaula 2 Essential Power Cords

Quantum Sound Improvement

Each year, I dedicate one review to exploring the often contentious world of audio cables, selecting what I believe to be a significant product in this category. This year's choice will surely spark lively discussions in the comments, given its price point and the technology used. My annual exploration allows me to delve into a subject that consistently ignites passionate debates among audiophiles and casual listeners. I always look forward to readers sharing their experiences and insights on how much audio cables impact their systems' sound quality and overall listening experience. It's fascinating to see the range of opinions—some firmly believe in the transformative power of high-quality cables, while others remain skeptical, viewing them as mere conductive materials.

It's important to recognize that, despite the comments exchanged, it is unlikely that anyone's belief will be changed through discussion alone. People have strong beliefs shaped by their experiences and preferences, making this a deeply personal topic. One reason I enjoy writing for Tracking Angle is the respectful tone upheld by our readers, even when opinions differ, so I am comfortable opening this Pandora's box once a year.

Last year, I chose to review the excellent Belden Iconoclast Series II cables. My interest in the subject of this year's cable review, the Bella Sound's Kaula 2 power cord and its scaled-down sibling, the Kaula 2 Essential, originated at the 2024 Southwest Audio Festival, where I noted Bella Sound's room as one of the weekend's highlights. In my show report, I said the Bella Sound's room was: Easily one of the best-sounding rooms at the show, ….had a transparency and emotional expression that was almost addictive. I returned to the room several times, and each time, I had to force myself to get up and move on to the next room. I cannot give a higher compliment.

I was even more intrigued when I discovered that the Kaula 2 Series uses Bybee Quantum Purifier technology. In my recent review of the Wells Audio Cypher II Level II DAC, I was impressed by the impact of the Bybee Quantum AC purifiers. One noteworthy aspect of my review was that I could compare the same product with the Bybee Quantum purifiers (Level II) and one without them (Level I). I consistently noticed a reduction in the noise floor in the Bybee-enhanced Level II version. The lower noise floor I experienced with the Bybee-enhanced Wells Audio products had me wondering about the application of Bybee Quantum AC Purifiers in power cords.

I contacted Mike Vice, designer and president of Bella Sound, to inquire about reviewing the power cords. Educated in physics and electrical engineering at UC Berkeley and Stanford, with decades of experience beyond that and over 40 patents, Mike Vice is an accomplished engineer and was a long-time friend and neighbor of Jack Bybee. Along with the power cords under review, Bella Sound makes amplifiers (stereo and monoblock) a Bybee-based power conditioner, and Mike tells me a preamp is in the works for 2025.

There are two versions of the power cord: the Kaula 2 ($5,500) and the Kaula 2 Essential ($3,000). I received a pair of each model to audition on my SMc Audio GT24 0.5 monoblock amplifiers. Before I discuss the cables themselves, let me get you up to speed on Jack Bybee and Bybee Quantum Purifiers.

Bybee Quantum Purifiers

Bybee Technology was founded by Jack Bybee, a former physicist who worked on classified military and government projects. The company is known for its innovative methods to reduce electrical noise and improve signal quality. Jack Bybee's background in quantum physics and his work on submarine technology for the U.S. Navy greatly influenced the technologies he later applied to audio. Unfortunately, Jack Bybee passed away in September 2020 at 89 years young.

The Quantum Purifier, Bybee Technology's best-known product, is a passive filter said to reduce noise and distortion in audio signals, improving clarity and detail. Bybee purifiers operate using principles of quantum mechanics, specifically related to quantum tunneling and electron flow modulation. Quantum tunneling is a phenomenon where particles, such as electrons, can pass through a barrier that would normally block them at a macroscopic level. Though this principle is more commonly used in advanced physics and technology sectors, the Bybee purifiers claim to harness it to affect the flow of electrical signals on a very small scale. The Quantum Purifier purportedly optimizes the electron flow through a circuit, filtering high-frequency noise and interference without degrading the audio signal. It does this by interacting with the electrons at a subatomic level to reduce thermal and electromagnetic noise that can negatively affect sound quality.

It is fair to say that Bybee Quantum Purifiers and their claims have garnered both strong supporters and critics. Some audiophiles and engineers argue that the improvements are subjective, while others insist that the sonic differences are fundamental and worth the investment. Of course, this engineering is above my pay grade. I am interested in how this product, which employs the Bybee Quantum Purifiers, sounds, not why.

If you would like to explore the Quantum Purifier further, here is a link to a more detailed explanation on the Bybee website.

Kaula 2

Kaula 2 Essential

Kaula 2 and Kaula 2 Essential

Crafted with meticulous attention to detail and years in development, the Kaula 2 series of cables exhibit construction that reflects their price point. They are manageable and flexible, making them practical for cable routing in a rack environment. However, it's important to note that additional space is required behind the component to accommodate the four-inch barrel/IEC connector. The Kaula 2 model features rhodium-plated connectors, while the Kaula 2 Essential comes with gold-plated connectors. Both models utilize the same three-conductor 13-gauge cable whose impedance characteristics are carefully controlled and essential to the overall design.

High-grade shielding materials and proprietary insulation techniques are employed to prevent interference. This shielding reduces the impact of electromagnetic and radio-frequency interference, which can add noise to the audio signal, muddying the sound or causing loss of detail.

I asked Mike to expand on the technology and the differences between the two cables. He kindly provided the following.

"The Kaula-2 series of AC cables was inspired by the work of Jack Bybee and his development of what he termed the "Quantum Purifier." Whereas Jack did himself explore its use in AC power cables, Bella Sound set out to drive the structure and utility of this technology to further efficacy by embedding it into an electrical environment that makes best possible use of the operating principles and enables it to perform optimally. Bella Sound began by redesigning the purifier to optimize its own performance. This objective was met and confirmed by conducting numerous painstaking comparative listening tests. We then embedded the new purifier into a network of correct reactance and fitted it to a cable of the optimal impedance. The assembly is then treated with an overlay of materials used in the new purifier and housed in a substantial shielding shell. The result is a striking advancement on the former cables built around the original Quantum Purifier technology."
"Our goal with the Kaula-2 Essential was to make the superb sonic achievement of our flagship product accessible to a wider range of audiophiles while retaining about 80% of the sonic value of the original. Accordingly, we have scaled back on some of the expensive materials within the Quantum Purifier, simplified the overlay shielding, and swapped out some of the external enclosure materials and contact interface plating. Everything that acts within the flagship product is still present in the Essential, and our own listening tests confirm that the uncolored noise floor reduction characteristic of the flagship Kaula-2 is indeed substantially present with the more aggressively priced Kaula-2 Essential."
"The enhancements we make to the original Bybee Quantum Purifier pertain to the quality and amount of proprietary substances within the device and also to an advantageous change in the physical structure that allows a more concentrated packing of those materials. Finally, the structure is extended physically - it is larger - in order to drive the performance to the limits obtainable within practical size constraints".
The Bella Sound website contains several excellent technical papers and articles to explore the subject further, plus articles dealing with general audio topics, like speaker cables, room acoustics, and having your cell phone in your listening room. Interesting stuff.

The Bottom Line ….. Sound Quality

· Soundstage and Imaging

First and foremost, the Bella Sound Kaula 2 is remarkable for its ability to enhance both the soundstage and imaging of an audio system. It expands the soundstage, creating a more immersive experience. By minimizing power-related noise and distortion, I experienced instruments and vocals occupying distinct and well-defined spaces within the auditory landscape. The enhanced spatial resolution allowed me to more fully appreciate each note, nuance, and subtle detail of a more clearly conveyed performance, enabling me to connect with the music on a deeper level. The Kaula 2 also reveals layers of depth within the soundstage, resulting in improved lateral separation and a compelling sense of proximity for both near and far sounds. With this layered depth, I could quickly identify vocals or lead instruments in the foreground, while ambient effects or background instruments were distinctly placed further back, creating a vivid illusion of a three-dimensional space. Of course, I have heard a sound field like this to varying degrees over the years, but not one this well-defined and focused.

· Bass reproduction

Another attribute that demanded my attention was bass reproduction and overall dynamics. Both instruments and voices were firmly anchored and strikingly lifelike. This cable delivered rich, controlled bass that never overwhelmed the other frequencies. It established a solid foundation and depth that felt natural and exceptionally well-defined, resulting in impressive clarity and focus. Moreover, the Kaula 2 exhibited an excellent sense of "attack" and "decay." These terms describe the system's capability to swiftly and accurately reproduce the onset and conclusion of each sound. This precision ensured that every note had distinct presence, space, and vitality.

· Midrange Clarity, Vocal Presence, and Neutrality

The Kaula 2 provides a neutral and transparent midrange, highlighting the subtleties of vocals and instruments, resulting in a more natural and lifelike presence. Listeners passionate about vocals or acoustic music will particularly appreciate the Kaula 2's ability to render midrange frequencies rich and full without sounding harsh or subdued. Tonal neutrality is a key feature of the Kaula 2's design. It does not impose any character on the music, allowing the natural tonal qualities of the source and equipment to shine through.

· Natural Treble Extension and Detail Retrieval

This cable offers extended, clean, grain-free reproduction of subtle high-frequency sounds along with a low noise floor. It enhances complex recordings by unlocking subtle micro details, such as the texture of a saxophone reed or the nuances of a violin's bow, all presented with impressive clarity. It delivers an airy sound that creates openness and clarity without overemphasizing specific details, allowing for prolonged listening without fatigue.

In numerous live recordings, distinct ambient details were consistently uncovered, enhancing the listening experience. Each session revealed subtle nuances and textures that had previously gone unnoticed, allowing me to develop a deeper appreciation for the unique acoustics of the recording venue. This greater awareness highlighted the intricate interplay of sound within the space and enriched the performances' overall atmosphere.

· Musical Flow

"Musical flow" refers to the natural and uninterrupted progression through a musical piece, where each element connects cohesively and invites the listener on a journey. This flow depends on rhythm, harmony, melody, and dynamic control, all contributing to a seamless transition from one section to the next. It also encompasses the pacing of musical phrases, transitions, and the overall structure, creating an emotional trajectory that fully engages the listener. This alignment of technical and artistic elements makes each note, chord, and passage feel interconnected, sustaining the emotional impact and depth. The Kaula 2 excelled in conveying this.

Concert Night at Casa Redmond

I cannot think of an album that better encapsulates all the qualities I've mentioned and brings them into focus than "The Köln Concert" by Keith Jarrett. I have played this album on every sound system I have owned since 1975 and am intimately familiar with it. When rendered correctly, this performance is a musical rollercoaster that leaves you emotionally spent by the end. Part 1 features twenty-six minutes of musical foreplay leading to a climactic conclusion that had me frozen in my seat, always anticipating the following note. Standout features included the hall's ambiance, the sense of audience movements, and the harmonic bloom of the piano, allowing notes to linger in space and combine to form an intoxicating musical elixir that I found myself getting lost in. Keith's well-known vocalizations sounded entirely human yet were presented as if they were another musical instrument rather than just his voice. His foot tapping on the stage echoed through the hall with a wooden resonance that felt remarkably real. The hammer attack was crisp and focused, and his use of the sustain, sostenuto, and soft pedals was easily recognizable. Even though I have listened to this piece countless times, the experience was uniquely exhilarating and mesmerizing with the Kaula 2 in place.

Ambient Silence …. How Black is Black?

Recently, I visited a local paint store to purchase some paint. When I approached the counter and requested a can of black paint, I was surprised to be handed three color strips showcasing 18 shades of "black" for me to consider. Similar to the overwhelming variety of black paints, the term "black background" in audio has a multi-faceted meaning that deserves closer examination.

When I refer to a "black background," I'm not just talking about silence; I'm considering the different qualities of that silence. For instance, the unsettling deadness experienced in an anechoic chamber, where sound seems to vanish entirely, creating an almost eerie atmosphere. Then there are the sterile soundscapes produced by some noise reduction systems, which can strip away subtle details in music, leaving an unnaturally quiet space that feels contrived, much like the quality of the "dead" space found in music playback on tapes processed with Dolby C, where the absence of noise can feel artificial. And, of course, there is a significant difference in the quality of this space in digital and analog reproduction.

"Music is the space between the notes," the famous quote attributed to the Impressionist composer Claude Debussy, emphasizes the emotions between the notes as listeners and musicians eagerly anticipate what will come next. The "black background" I refer to represents the "fabric" that connects the notes. Many attempts at noise reduction aim to lower the noise in that "black background," but in doing so, they also compromise the very fabric that binds the music. The Kaula 2 cables create a lower noise floor while preserving that essential musical fabric.

This is why I had such a profound experience with the Keith Jarrett recording. The flow and decay of the notes were beautifully rendered against a seamless musical backdrop, allowing them to linger and intertwine instead of feeling like a collection of isolated notes. Additionally, reducing the noise floor revealed subtle details, enhanced the harmonics, and created a more intense and connected listening experience.

Kaula 2 Essential

Kaula 2 vs Kaula 2 Essential

Mike previously described the goal of the Kaula 2 Essential cable as achieving 80% of the performance of the Kaula 2 while being priced 45% less. I can confidently say he has succeeded admirably. With the Kaula 2 Essential, he has maintained the crucial neutrality and the positive attributes previously mentioned, albeit not quite at the level found in the premium cable. There were instances when I compared the two cables and noticed little to no difference between them. However, at other times, the Kaula 2 cable emerged as the superior choice. This situation illustrates the dreaded concept of "diminishing returns," where achieving that final 10-20% improvement can cost almost twice as much.

In many cases, as you move down a brand's lineup from its best product, you encounter significant changes; however, I was pleased to conclude that the Kaula 2 Essential is genuinely a scaled-down version of the more expensive Kaula 2. It yields a slight reduction in the quantity of sonic impact but not in the quality. Kudos to Mike on accomplishing this.

Conclusion

At $5,500, the Kaula 2 is undeniably a significant investment, positioning it among top-tier cable products. However, the reduced noise floor, improved spatiality, natural representation of instruments, and dead neutral tonal balance delivered a level of realism not previously achieved in my room and transformed familiar tracks into new sonic adventures.

Bella Sound offers an audition program that lets you experience whether the cable similarly impacts your system. I appreciate when a manufacturer steps up to the plate to allow prospective buyers to confirm if the product positively impacts their system.

And remember, the $3,000 Kaula 2 Essential gets you a massive helping of what the topline cable brings to the party.

I have sold and auditioned dozens upon dozens of brands of cables over the years, many costing much more than these cables. Still, I have yet to hear a more tonally accurate, dynamically expressive cable that recreates a soundstage as magnificent as these cables. I have heard one or two of those elements in other cords, but I have never heard them all together in one cord.

If you want, roll your eyes at the concept of why they sound this way, but frankly, I don't care if they used a Flux Capacitor, Dilithium Crystals, or a Mr. Fusion reactor. The bottom line is that this is a damn good-sounding power cord that positively impacted my system as much as changing a component has.

Lastly, I am not insensitive to the price point of these cables, and I wish I could report on a cable at a lower price point that impacted my system the way these cables did. My search for that cable will continue, but until I find it, these power cables will occupy the distinction of being some of the best recreators of a musical experience I have had in my system to date.