Audionet STERN Preamp HEISENBERG Monoblock Amp

Ye Olde Editor: a portrait by John Robinson

Audionet's STERN and HEISENBERG: Back to the mountaintop again!

Fair warning: This is yet another one of my evaluations that is not going to be a typical "review."

No, not with these designs.

This is going to be more of a culminating mediation on my experiences with the STERN and HEISENBERGs, and the quality of these extraordinary designs. I'll link back to several earlier reports, which I invite you to read or re-read, in order to get the progression of my thinking and evaluation. For this final essay has been most of a year in the making, and has earlier experiences that it builds upon.

Rewind.

I've been listening to the STERN and HEISENBERGs since last fall. That was when Bill Parish of GTT Audio, a long-time audiobud of mine, invited me to the premiere of these new reference products from Audionet. Bill's largest listening room is the finest that I've heard to date. I've been there several times over the years, and always have a mind- (and ear-) blowing time. (Plus those fine cigars and Port!)

The fall of 2016 saw my first Audionet experience, in conjunction with the brilliant YG Acoustics Sonja XV Loudspeakers. That trip was to see their Pre G2 preamp with a set of no less than four MAX Monoblocks. It really knocked me onto my hindmost audio parts. You'll see that back in the halcyon days of Issue 87, right HERE. The KRONOS Pro LE with the Black Beauty tonearm and the Air Tight Opus 1 MC, with everything wired up with Kubala-Sosna Elation! cabling rounded things out. Choice!

In the autumn of 2017, I reported on my second trip to the audio mountaintop HERE. This time, the Sonja VX's were powered by the Audionet STERN reference preamp and a truly nuclear set of four HEISENBERG reference monoblocks. Caramba! Talk about authority and presence! It was really shocking, as I noted in my cited report. The analog front end had the KRONOS SCPS power supply added to the KRONOS mix…a clear step forward. And Kubala-Sosna's new top-o'-the-heap cables, the Realization line, was the strap-together. (The Realization line really is a very substantial step forward, hard as that might be to believe for those who already own Elation! cables.)

The STERN at Bill Parish's reference listening room at GTT Audio

This was followed up by a return trip to Bill Parish's GTT Audio reference room. Twice, even. Once with the STERN and a single pair of HEISENBERGs on my way to Munich 2018…

…while the second was with the STERN and a fearsome foursome of HEISENBERGs when I stopped over in New Jersey again on my way back from Munich.

On the show world side of things, I got an earful too. Earlier this year, I got to hear the STERN/HEISENBERG (single pair) tandem at work and play at two different events. The first was at AXPONA 2018, where, once again, I was extremely impressed by the way that the Audionet designs drove this room with authority and confidence, even with a simple pair of HEISENBERGs powering the YG's.

The Audionet STERN/HEISENBERGs (a monoblock pair) in action with a four-way stack of YG Acoustics Sonja XV Jr Loudspeakers at AXPONA 2018. An Audio Oasis! Award winning combination…

The following month, I saw I talked about the STERN and HEISENBERG demo that I saw at Munich 2018. Part 1 of my notes about the show can be found HERE, with Part 2 (including my Audio Oasis! Awards for the show) HERE. Audionet was a major presence at Munich, and I got a chance to hear a single pair of HEISENBERG monos fed by the STERN driving a pair of totally unfamiliar tall Dynaudio loudspeakers.

The Audionet STERN and HEISENBERGs with Dynaudio Loudspeakers at Munich 2018

Thomas Gessler, CEO of Audionet, with the HEISENBERG monoblock at Munich 2018

It didn't matter that I didn't know the Dynaudio speakers, or that it was all happening under major show conditions. Not at all. The results were really impressive…thus the Audio Oasis! Awards that I gave to the Audionet room at Munich. Re-read part two of my Munich reports for the details.

Specifications

For those interested in specs, here are those for the STERN and HEISENBERG.

Advance warning: they're truly amazing.

STERN

Frequency response: 0–2,200,000 Hz (-3 dB), DC coupled, 0.3–2,200,000 Hz (-3 dB), AC coupled
THD+N: <-104 dB @ 20 kHz, <-116 dB @ 1 kHz
SNR: > 123 dB, 4 VRMS
Channel separation: >144 dB, 20–20,000 Hz
Output impedance: 24 Ω real (Cinch line), 48 Ω real (XLR)
Output current: max. 60 mA
Power consumption: < 0.5 W stand by, typ. 100 W
Mains: 220/240 V or 110/120 V, 50..60 Hz, Rhodium (Furutech)
Dimensions: (Vertical) Width 270 mm x Height 500 mm x Depth 505 mm. (Horizontal) Width 450 mm x Height 320 mm x Depth 505 mm
Weight: 38 kg

HEISENBERG

Output power: 530 W into 8 Ω, 1,050 W into 4 Ω, 2,100 W into 2 Ω
Frequency response: 0–700,000 Hz (-3 dB)
Damping factor: > 1,800 @ 10 kHz, > 10,000 @ 100 Hz
Harmonic distortion: k2 typ. -117 dB for 25 W into 4 Ω, k3 typ. -123 dB for 25 W into 4 Ω
Intermodulation: < -110 dB SMPTE 100 Hz : 20 kHz, 4 : 1, 50 W into 4 Ω
THD + N: > -106 dB @ 1 kHz, 25 W to 700 W into 4 Ω
SNR: > 125 dB
Filtering capacitance: 200,000 µF
Input impedance: (Line input) 50 kΩ, 33 pF, (XLR input) 7 kΩ 66 pF (line to line)
Power consumption: max. 2,400 W
Mains: 220..240 V or 110..120 V, 50..60 Hz
Dimensions: Width 270 mm x Height 500 mm x Depth 490 mm
Weight: 66 kg
Note that the STERN features an excellent I/O set: 4 pair RCA line, Rhodium (Furutech), 2 pair XLR balanced, gold plated (Neutrik), 1 D Sub 9 serial port (control only), 1 SMA for WLAN (control only)
Outputs: 2 pair Cinch line, Rhodium (Furutech), 1 pair Cinch inverted, Rhodium (Furutech), 2 pair XLR balanced, gold plated (Neutrik), 2 Audionet Link, optical, 1 connector, gold plated, for additional earth connection

As I said previously, I tried both sets of outputs from the STERN, unbalanced (RCA) and balanced (XLR), but liked the sonic presentation of the RCAs better.

Into my listening room…

So…

Having heard the STERN and HEISENBERGs in assorted other settings, and being thoroughly knocked out each time, it was time to bring these bad boys home to my own listening room. No matter how great components sound elsewhere, there's nothing like hearing them in your own well-known space.

At last! The STERN and HEISENBERGs arrive in Portland…

…for a several-month visit, near the end of April, 2018. Hefty, but extremely well-packed in their sturdy professional shipping cases.

Bill Parish was able to send these to me late last April, and they stayed until mid-summer. This gave me the time to confirm (or deny) my earlier impressions about the quality and capabilities of Audionet's reference designs right here at home plate.

The Audionet STERN on the top shelf of our Stillpoints ESS Rack #2 with Ultra V Isolation Feet.

There were two main system configurations that I used to evaluate the Audionet reference beasties.

The HEISENBERGs on the Critical Mass Systems QXK Rack with Kubala-Sosna Elation! unbalanced interconnect

The first system consisted of:

Audionet STERN preamp
Audionet HEISENBERG monoblock amps
Evolution Acoustics MM2 Loudspeakers with EXACT External Crossovers
Xact Audio The Beat LT Turntable with van den Hul Colibri Signature Stradivarius MC cartridge (see my review of this turntable system HERE)
PASS Labs Xs Reference Phono Amp (two-box with separate power supply)
Playback Designs Sonoma Stack (Merlot Quad DSD DAC, Syrah Music Server, Pinot ADC, and OPPO BDP-103 OpBox universal disc player; see HERE for my review of this system)
Stillpoints and Critical Mass Systems racks and isolation devices
Cabling by Kubala-Sosna (Elation! and Realization) and Synergistic Research
Kubala-Sosna XPander Power Distribution Unit
Synergistic Research Atmosphere XL4, Active Grounding System, and HFTs
van den Hul Extenders (see my review HERE)

The second system:

As above, with the exception of the Wave Kinetics NVS Reference Direct-Drive Turntable with the KLAudio Linear Tracking Tonearm and custom phono cables and the van den Hul Colibri Signature Stradivarius MC cartridge as the analogue source.

I had started with Kubala-Sosna Elation! XLR cables for a few days. At the advice of Audionet and Bill Parish, however, I switched to Elation! unbalanced cables. Bill said that the unbalanced section was smoother and more musical in presentation. After listening to the improvements that I heard when I made the change, I would agree with Bill. Unbalanced was better, definitely. That's where I stayed for the rest of the project.

Shortly afterwards, Joe Kubala sent along a couple of Realization power cables and a pair of Realization RCA interconnects, so that I could improve the performance of the PASS Labs Xs Phono Amp and the Merlot Quad DSD DAC. I was already using a Realization USB cable between the Syrah Music Server and the Merlot DAC, and knew how exceptional it was. And yes, the power cables and interconnects were also definitely much better, like unto their USB sibling. Greater transparency, detail, and dynamics, while also gaining harmonic rightness. You want these. (You may not be able to afford them, but you do want them.)

Xact Audio's The Beat LT turntable, one of the sources used with the STERN and HEISENBERGs

Once the Audio reference-level kit was in place, I listened to four months' worth of the usual suite of SACDs, DSD recordings…especially Double and Quad DSD…and LPs. Not to mention the constant stream of the new stuff that is always floating in with the tide here at PF Central. For this essay, I'm just going to list some recommended representative albums that I listened to with the STERN and HEISENBERGs. (If you're newer to high-end audio, this may help you to spot some titles that you would like to add to your collection.) At the end, I'll summarize the performance of the Audionet gear with these recordings.

To wit:

Yes, I know: these are many (but not nearly all) of my usual gang of references in the world of RCA Living Stereo reissues on LP and SACD. I won't repeat what I've said about them in the past; these are classic recordings, exceptionally well reissued by Analogue Productions nowadays. All of them feature wonderful performances, great dynamics, fine soundstaging and imaging, and world-class production. If you don't have them, then you need to get them. No audiophile reference library is complete without them (and many more titles that I might list from that series).

The LAOC Audio Society Limited Edition (500) version is the one to have. An absolutely amazing pressing…state of the art. In fact, it may well be the single finest pressing that I've ever heard. It's already out of print; you'll have to scrounge around to find a copy.

Stockfisch's reissue on SACD of Andreas Rohde's Resonance is a brilliant performance in the relatively rare realm of 12-string guitar recordings, gotten to DSD in an exemplary way. This is the second title in Stockfisch's Analog Pearls series. Waylon Jennings is Vol. 1. Get them both, because they're simply smashing. In fact, anything that Stockfisch Records produces is worth its weight in gold. I've found that I can buy their SACDs without having to preview them.

Brian Eno's Music For Installations on a 9-LP set. Haunting, complex, hypnotic compositions that are well recorded, and that will challenge an audio system to untangle Eno's musical Gordion Knots. Can yours? (Audionet could.)

Oh yes. Dean Can Dance's Into the Labyrinth. It's on both SACD and Mobile Fidelity Silver Line LP…I have and tried both. Killer with the Audionet ref gear. You didn't think you'd escape without my mention of this constant evaluative reference among my LPs, did you? Side one, cut one. Try it.

It's Muddy. It's one of the greatest blues recordings of all time. And it's killer on both SACD and (especially) the Analogue Productions 45 RPM.

Want to know more about why you should have this album? Read Dr. Wayne Goins brilliant review for PF right about HERE.

Yessir! Howard Shore's complete musical soundtrack for The Lord of the Rings movie trilogy is now out, in a trilogy of LP box sets. (The DVD set came out years ago. We have that, as well.) I had the set for part one, The Fellowship of the Ring, while the STERN and HEISENBERG were here. I couldn't resist; I listened to the whole set, straight through. (I have since added the second and third box sets.)

Dream state for me. Definitely luscious production values, and a fine performance. Certainly quite dynamic in passages, and contemplative in others. If you've seen the movie…and who hasn't?...then you know what I mean. Jump fast: Set one isn't inexpensive, but if you love the music…well, here it is. Definitely good for soul and system.

Ongawa! Just recently released: the Rolling Stones box set, covering their years from 1971-2016. This finally rounds out my Stones collection, since I have the Mobile Fidelity box set of their ABKCO years on LP; the 22 SACD collection of the ABKCO years; the set of 11 or 12 LPs reissued from the DSD transfer of the ABKCO years; and now the later years, in one big LP box set.

16 albums; 20 LPs. Luscious.

This one arrived while the STERN and HEISENBERG were here. It was irresistible to pop ‘em on and turn it UP! Want to try dynamics, rhythm, and jump in your listening room? Check this set!

For a brilliant recording of a diva at her peak, try Linda Ronstadt's What's New. It's available on SACD and a brand-new release on 200 gram LP from Analogue Productions. Lush, seductive, and heart-stirring, you'd have to be dead and gone not to fall in love with it from the first track. It was a perfect way to make myself smile…and work out the Audionet reference components at the same time.

A classic! Ellington Masterpieces is an absolutely no-doubt modern masterpiece of reissuing from Analogue Productions. Monophonic from 1950…one of the very early LPs…pressed on 200 grams with Ellington and company enjoying the elbow room of much longer track times. The version of "Mood Indigo" on this magnificent LP is the very finest that I've ever heard from Ellington, bar none. Mono or no, this will strike you as weirdly holographic, if your audio system has the chops to do things right.

No got?

Get!

A stellar performance from Dean Martin, with brilliance of performance and production. Reissued right around the same time as Analogue Productions' Ellington Masterpieces, Martin is at his mellow best in this collection of tracks. The 45RPM LP on 200 grams is a great addition to your library, even if Dean isn't entirely your cuppa joe. Check the midrange!

Bob Attiyeh and Yarlung Records continues to please and impress with its albums in both Quad DSD and on LP. I listened to both versions while hosting the STERN and HEISENBERG, and was quite pleased with the ease, authority, and transparency that I heard in their company. Every nuance of this recording was laid out clearly, with exquisite detail. Certainly Mabuchi & Co. were very well served by the Audionet reference electronics.

Conclusion

I could go on and on with the wonderful recordings that I used to finish qualifying the virtues of the Audionet STERN and HEISENBERGs, but it would be both redundant and pointless. It was clear to me in advance of their arrival here that I was going to be hearing first-rank world-class designs. My only question would be how they would fare in the intimately well-known audio precincts here.

As it turned out from the beginning, the answer was simple. The Audionet references were absolutely superb.

In fact, from beginning to end over about four months their performance was flawless. I couldn't hear any aspect of fine audio reproduction that they didn't excel at without any qualification whatsoever. Make your list of audio virtues: transparency. Soundstaging. Imaging. Detail. Dynamics…no matter how huge the source signal. Harmonic balance. Phase and time correctness. Rhythmic rightness. Musicality. Midrange gorgeousness, without losing bass control or ultrasonically extended high frequencies. Reliability. Thermal stability. (The HEISENBERGs remained at about 100 degrees F throughout their time here.)

Above all, the STERN/HEISENBERGs tandem was absolutely authoritative here, with presence and ease to burn. Nothing that I had here, from LP to SACD to Quad DSD…threw them. They made reference-grade, no-doubt-about-it, shut-up-and-listen music endlessly. All day. Every day.

The specifications alone would indicate in theory that the electronics should be extraordinary, but actually hearing these designs in multiple places over time is where the overwhelming proof is. The sheer there-it-is-ness of the music cannot be argued with.

What I experienced in my listening room during these four months confirmed what I had heard in previous sessions in other times and places: the Audionet STERN and a pair of the HEISENBERG monoblocks were standing at the top of my experiences over decades in high-end audio over decades.

In fact, I'll have to go further than that.

To this point in time, the Audionet STERN and HEISENBERG reference designs are the very best that I've ever heard in my listening room, top-to-bottom, front-to-back, and side-to-side.

Furthermore, if you take the STERN and go with two pairs of HEISENBERGs…four monoblocks, total, which I've heard in Bill Parish's extraordinary reference listening room…then I can be categorical: That configuration is the best preamp/amplification that I've ever heard anywhere, anywhen, to this point in time, period.

Ne plus ultra.

If you've been reading my evaluations over the decades, you'll know how rare (almost unknown) it is for me to say anything like this.

So, pay attention. This is the high-end audio mountaintop…for here, for now. Don't miss it!

If you are operating in this budget range, then you simply must not purchase anything else until you listen to the STERN and HEISENBERGs in operation.

And that, amigos, is the name of that tune….

Audionet STERN Reference Preamplifier

Retail: USD $45,000

Audionet HEISENBERG Reference Monoblock Amplifier

Retail: USD $105,000 per pair

Audionet

Berlin, Germany

http://en.audionet.de

+49 (0) 30 233 24 21 18

[email protected]

US Distributor

Bill Parish, GTT Audio