This review feels very much like an opening act, following the headliner.
In the July/August 2020 issue of TAS, Greg Weaver penned a review of the Audionet Stern linestage and Heisenberg monoblocks, declaring the Scientist Series both the reference-level cat’s meow and pure audiophile shizzle (i.e., he liked them very very much). His review was thorough, well conveyed, and left little to add. Now the Humboldt combines technologies from Audionet’s $150k reference electronics into a huge, and hugely ambitious, integrated amplifier—the $55k Humboldt.
Friedrich Wilhelm Heinrich Alexander Von Humboldt was a Prussian scientist and explorer (1769–1859), who is best known for his analysis and understanding of how plant species are distributed throughout the world. He was a botanist, expert geographer, naturalist, explorer, and polymath. He is considered by some to be the father of ecology, and one of the first great environmentalists. Audionet’s U.S. distributor, Bill Parish of GTT Audio, is none of those things, although I’m pretty sure he has a garden in his backyard. He is, however, a fervent supporter of the company, and has been for many years. I don’t think anyone was more sincerely excited about the Scientist Series introduction than Bill, except maybe Thomas Gessler, Audionet’s International Sales Manager. Thomas’ passion for meticulously crafted audiophile equipment, whose specs settle between untouchable and unmeasurable, is well known in the industry. Audionet’s “Lighthouse” project, begun in 2013, was an all-out assault on what could be achieved, and the obvious first step was a linestage and monoblock amplifier. Enter Stern and Heisenberg. The Humboldt is the logical next step in the model lineup. For those who can’t afford or can’t accommodate separate components, the Humboldt is the solution. I offered Mr. Gessler the opportunity to describe what makes the Humboldt special; his response is unsummarizable. (I am well aware that is not a word, but it wasn’t.)
Thomas responded, “With Stern and Heisenberg, Audionet has attempted to redefine what is possible today in sound and music reproduction without regard to the effort and cost. It was to be another ‘Lighthouse’ project, with which we wanted to tear down the existing boundaries and redefine the sonic horizon. Thus, we spared no expense and effort and invested all our heart and soul. From conception to industrial design, circuit design, electronic components, and materials, we meticulously redesigned, tested, experimented, and validated everything. As a result, we have created pre- and power amplifiers that define the limits in terms of speed, stability, resolution, distortion, and noise, and in most cases are better than the competition by dimensions. Finally, audio does not sound like a machine any more—just pure, free, light, fine, delicate, and authoritative music and listening pleasure. How do you bring this all together in one housing? First of all, by making no compromises with regard to everything that is relevant to sound reproduction. It’s not the dimensions of a power supply, but its construction and its components that make the bigger difference. A smaller power supply will, of course, result in a loss of possible maximum performance. But this is something every customer has to decide for himself—what level of performance is required for him. By reducing the size of the power supplies, we gained a lot of space without any loss of sound quality. We were also able to reduce the size of the pre- and power amplifier boards because of the lower potential power requirements. But, also, without any noticeable loss of sound, because we did not abandon the decisive circuit details nor any components and materials relevant to sonic quality. Humboldt is, therefore, essentially a careful audiophile downscaling in the sense of potential absolute performance, without sacrificing the decisive sonic and technical merits of Stern and Heisenberg! If you want the absolute sonic and performance limit, choose Stern and Heisenberg; if you want the sonic and performance limit of an integrated amplifier, choose Humboldt. Like its big brothers, Humboldt sets the benchmarks of speed, stability, distortion, and noise for integrated amplifiers. And Humboldt also sounds like nothing: pure, free, light, fine, delicate, and authoritative music and listening pleasure. Actually, very simple, but technically, a Herculean task.”
The technical details, case design, inputs, and features were well explained in Greg’s review, and do not need to be reiterated as they are nearly identical, other than the obvious reduction in power supply, the single-chassis design, and the subsequent output-power reduction to 320Wpc into 8 ohms, 460Wpc into 4. For most, 320Wpc into 8 ohms is more than sufficient. For more power, look to the Stern/Heisenberg combo, and ye shall be satisfied. There are no DAC or phono modules available. As Bill Parish explained, “The concept of plug-in modules is simply not in conjunction with the level of performance the Humboldt has attained.” The Humboldt is built with the design principles of NASA, the resilience of a Sherman tank, the ease of use demanded by Apple, the aesthetic flair of a Manhattan plastic surgeon, and the engineering prowess of, well, a German engineer. Prächtige Skulptur!
Sonically, Humboldt resembles the atmosphere around Mount Everest. This integrated amp offers clarity, a complete absence of pollution, unrestricted vistas of majesty, the power and speed of an avalanche, and the romance, passion, and intensity of Into Thin Air. (See how I stuck with the Everest theme there?) The noise floor is also perceived like the “are they even there?” distant plains of Nepal as seen from Everest’s summit, 29,032 feet below. And like the wonder Everest is, the Humboldt’s presentation is natural in its truest form: smooth and mild-mannered when it needs to be, yet able to rage like Vesuvius. There is a variation and richness of timbre, which I perceived as simply better differentiated, with more palpable and clearer colors than most of what I have heard previously. Low-end extension is simply taut, unrestricted, and visceral without haze or savagery. Layering of the soundstage is on a completely different canvas, as if painted on a mountain wall as opposed to the confines of a typical canvas. The high-frequency reproduction is effortless, while never calling specific attention to itself. I found the midrange to be ever so slightly highlighted in the lower mids on some speakers, although this was imperceptible on others.
With the finesse of a French painter and the speed and handling of a McLaren 650s, the Humboldt is the fundamental expression of Thomas’ Lighthouse project. In essence, it takes what it is given, amplifies it, and sends it to the speakers without otherwise affecting the signal in any perceivable way. Imagine, if you will, watching water from a crystal-clear mountain spring silently fall off the edge of a great waterfall, plunging faster and faster. down thousands of feet to a cool blue lake below. The water is imbued with the energy that gravity exerts upon it; yet, the water itself remains completely pure, untouched, and unchanged. A “gravity amplifier,” as it were.
Original Resource is Articles – The Absolute Sound