Technical Data

(NOTE: While HUMBOLDT is being reviewed by the leading German and international magazines, this section features the test reports on his brethren STERN and HEISENBERG! Apologies for any inconvenience, but hey, it’s the ULTIMATE series, so this is just a family affair. You may deduct a few percents from the prose herein for yourself, reflecting that obviously much larger reduction in price. Thank you, much obliged.)

AV Showrooms

Review HEISENBERG
Product of the Year + Gold Award by AVShowrooms for our statement Amp HEISENBERG. It doesn’t get better than this in the High End, guys. Thank you!!!

Stereo Times

“The bass was quick-footed, articulate and most importantly it conveyed a musicality that belied both its size and build. All I could say was DAMN! Ironically, instead of more powerful, the system appeared more relaxed and resolving – as if the added wattage aided in providing less stress and more realism. In a sense, it sounded as though the Heisenberg/Stern combo took full control of the massive YG XV’s many individual drivers and made them a single source.

The very look and feel bespoke “state of the art” throughout while the sound is powerful and taut, yet elegant and ultra-refined. Voices hover above the floor at the right height and size but elicit a sense life that’s quite uncanny for a solid-state design. Music just flowed into this huge listening space in way that it had not in the past. It made the room seem smaller and more intimate. Weird. This made it somewhat difficult to concentrate on anything except the music. What higher accolade is there when a system can achieve that?

I don’t know what else to say except that listening to the Audionet Heisenberg and Stern combination was truly an adventure!”
Stereo Times, Clement Perry

the absolute sound

“We chose to listen exclusively to LPs for this audition. I got to spend the entire day listening to this remarkable system, and virtually every LP we played (I had a dozen of my own favorite records with me) left me astounded. From the moment the needle landed in the groove, the utter naturalness of the presentation became apparent. I was hearing subtleties of hall and performance ambiance that I’d never before heard in all my years of listening to this LP on literally hundreds of systems. Transients were crisper, more sharply and accurately delineated, tone color and texture were astonishingly accurate, and every aspect of the presentation was depicted with full, honest bloom, accurate weight, and ample body.

Dynamic scaling was spectacular, and I was overwhelmed by the degree of ambient detail conveyed. The way this system recreated the sound of a snare drum—its location, size, tone, body, and retort—was chilling. This system expressed a fine degree of delicacy and finesse that I’d never experienced prior, and yet, at the same time, there existed an enhanced measure of power and speed. Both of these characteristics coexisted in equal measure; neither showed compromise.

An absolute revelation of the musicians’ spatial relationships within the soundstage and of vibrant, faithful timbre. And the rhythmic pace, the timing and drive of the music, had never sounded more frenetic!

During my time in front of this system, my impressions about a number of attributes that this new linestage and monoblocks demonstrated solidified. One was the overwhelmingly conspicuous absence of any vestige of transistor pall, glare, or grain. Moreover, all instruments, both in their singular, individual voices and in their specific locations throughout the soundstage, had never been so starkly apparent and yet so convincingly natural sounding.

Add to this the expressive and seemingly unflappable sense of unrestricted power and control, and you have a series of electronics capable of recreating a sense of realism unprecedented in my experience of three-plus decades of reporting on the art of music reproduction.

The Stern preamp and Heisenberg monoblocks push the bar to previously unattainable levels.

In short, the combination of the Audionet Scientist Series Stern and Heisenberg monoblock amplifiers establishes a new benchmark.”
the absolute sound, Nov 13th, 2017, Greg Weaver

Hi-Fi+

“What is more, low-level textural, transient, and timbral details were rendered in a more complete and holistic way and with a heightened sense of focus and nuance. As a result, the voices of instruments and human singers became at once more natural sounding, more pure, and more focused. The sheer effortless clarity I heard was unlike anything I had heard from any hi-fi system in the past, and as a result, large-scale choral and orchestral works took a quantum leap forward in overall intelligibility and lucidity. Even more depth, more focus, and much more bass detail, yet that is exactly what the Stern/Heisenberg electronics delivered. Third, (and perhaps this come as no surprise) the extremely powerful Heisenberg amplifiers (1,050 watts @ 4 ohms) gave the system a certain “ceilings unlimited” quality in terms of dynamics.

Now those raised in the ‘smaller-is-better’ ethos of hi-fi amplification might well wonder if blockbuster amps such as the Heisenbergs could be anything but muscle-bound, but that isn’t the case at all. In fact, I suspect the Heisenberg might just be the most fleet-footed and agile audio amplifier I’ve ever experienced. Two major benefits of the Stern/Heisenberg package are these: first, the strengths of ancillary components seem greatly magnified by the Audionet electronics, and second, with the Audionet components in play recordings can be explored in much greater depth and with more insight than listeners might have thought possible.

In case you’re wondering, I’m not the only one who finds these components beautiful; in fact, the Stern is now on display as part of the Smithsonian’s National Gallery.

The bottom line is that Stern and Heisenberg have, in my opinion, raised the performance bar for high-end audio electronics, and I say this having heard top-tier components from Audio Research, Constellation, Dan D’Agostino Master Audio Systems, Naim Audio, Pass Labs, Soulution, and others). They also serve admirably as audio objets d’arts that are, in a very literal sense, of museum quality. Therefore, I would encourage listeners to go hear and see the Audionet components, if only for a glimpse of what’s possible when performance constraints are removed.”
Hi-Fi+, Nov 08th, 2017, Chris Martens

Positive Feedback

“The Stern and Heisenberg have a serious, we’re-not-playing-around, visual that will stop you in your tracks with their scale, cosmetics—and ambition! Both units are encased in nearly identical aluminum chassis of flawless German metalwork (by German design legend Hartmut Esslinger). The Stern has already been placed in the Smithsonian’s National Gallery of Art. The Stern has got to be one of the largest preamps on the planet. Why so much real estate? I was told the interior is chock-a-block with circuitry. It boasts some amazing specs. There’s more: more tone, more timbre and, most especially, triumphantly, the grandest dynamic peaks I’ve encountered in residential audio. I’m always fiddling with or critiquing tonal balance—it’s rare to find a system that leaves me with no complaint—but with this rig I didn’t want to change a thing. The tone was BIG, with 100% saturation, and striking in its uniformity from top to bottom. The treble was sweet and extended, but never harsh, and certainly not of a quality I associate with solid-state. The mids were clean; the bass full, round and tight. All of uncommon purity. Yay! The tone showed no compromise. The instruments on The Blues and the Abstract Truth grew from ff like you get with other über components, and then pushed beyond that to full fff, where no amp has gone before. Edge-of-the-art for what’s possible in audio reproduction.”
Positive Feedback, Issue 94, Marshall Nack

Audiotechnique

Review HEISENBERG
“Stern and Heisenberg take the transistor amplifier to a new level. An ultimate position, a new benchmark. Most strongly recommended by Audiotechnique. … This Audionet system is ABSOLUTELY THE BEST OF TRANSISTOR AMPLIFIER TODAY, with the highest end performance.”
AUDIOTECHNIQUE magazine Hongkong, Editor-in-Chief Lincoln Cheng

i-fidelity

Review STERN and HEISENBERG

“With the Stern preamp and the Heisenberg mono blocks, Audionet chimes in a new chapter of amplifier building. In more than one respect this trio is blasting conventions; sound quality and price fall definitely within. The attractive – also because it won’t reveal itself at first glance – styling by Hartmut Esslinger and the extent of innovative hightech from Audionet’s R&D department form in this triumvirate a passionate symbiosis which brought me a true joy of heart. The fact that these components bear the names of Noble Prize winners won’t cause any harm, for Otto Stern and Werner Heisenberg would certainly be proud to stand bail as namesakes for the new i-fidelity.net references.”

hifi&records

Review STERN and HEISENBERG

“Unheard-of-supremacy… A new leaf in the book of ampbuilding… Soundwise, musically and aesthetically the three towers are performing in a different league, a new class that needs no other superlative.”