Note: for the full suite of measurements from the SoundStage! Audio-Electronics Lab, click here.

Last August, when I auditioned the Hegel H600 integrated amplifier, the Norwegian brand’s flagship model ($12,500, all prices in USD), I was in for a surprise. Over my 17 years as a SoundStage! reviewer, I’ve spent considerable time with solid-state class-AB integrated amplifiers and have formed some notions about their sound. I therefore approached the H600 with certain expectations. It didn’t take long for it to compel me to revise those notions and expectations. What set the H600 apart from other integrated amplifiers I had heard was the sheer effortlessness of its presentation, especially at high volumes. I normally listen to music at what I consider moderate volume; with the H600, because it was so easy on my ears, I found myself playing at higher and higher volume levels. It was a revelatory experience for me to hear what my system can sound like with the H600 as its backbone.

Back in the spring, I received a review sample of Hegel’s newest integrated amplifier, the H400 ($6995). This model replaces the H390, which Doug Schneider wrote about in December 2019. Since the H600 had left such a lasting impression on me, I wondered whether the H400 might do the same.

Physical design and interface

While Hegel has made several notable changes to the H400’s construction, it still looks like every piece of Hegel kit I’ve ever reviewed or seen, an embodiment of Scandinavian minimalism. I have always appreciated Hegel’s utilitarian approach to design, but some prospective buyers may view the H400’s aesthetics as rather spartan for an integrated amplifier that retails for nearly $7K.

At 5.9″H × 16.9″W × 17.3″D, the H400 is a hair taller than the H390 and just as heavy, 44 pounds. A more significant change can be seen in its build quality: the top cover appears tighter and smoother, and it has oblong, purportedly more effective, cooling vents. It still doesn’t quite match the H600 top cover, which exudes quality with its thicker material and milled cooling vents. Of course, the H600 is nearly twice the price of the H400. The aluminum volume and input-selection dials are similar to the ones used in the H600, and they felt equally smooth in operation. These two dials can be used to adjust all other functions, as can the RC8 remote control—a nice block of milled aluminum whose quality befits a product at this price. The H400’s front panel is also milled from solid aluminum, which is then bead blasted and anodized.

The H400’s power output remains unchanged from the H390: 250Wpc into 8 ohms. Hegel claims it’s stable into a 2-ohm load, so it should be able to drive almost any speaker you’d want to use it with. The H400 incorporates Hegel’s SoundEngine2, a patented error-correction circuit designed to eliminate the crossover distortion inherent to class-AB topology. The voltage amplification board of the H400 is new and is said to improve the sound from all inputs. It had been newly updated in the H600 at the time I reviewed that model, so it appears that the H400 has benefited from trickle-down technology originally developed for its big brother.

Digital front end and streaming platform

The H400 seems to have been primarily a response to a chip shortage that resulted from a fire at the Asahi Kasei Microdevices (AKM) semiconductor factory in Nobeoka, Japan, in 2020. It is the third integrated amplifier with a DAC I’ve reviewed in the past year that had veered away from an AKM chip; the other two were the H600 and the Rotel Michi X5 Series 2. Interestingly, both Hegel and Rotel settled on Sabre DACs from ESS Technology. And from communications I’ve had with the two companies, they don’t look back. They are happier with the performance of the newer Sabre chips than that of the AKM ones they replaced.

Hegel says the most significant improvement the H400 has over its predecessor is precisely that new digital front end. It uses the same ESS ES9038Q2M converter employed by the H600, though the implementation is different. The new DAC, Hegel claims, offers better resolution and fluidity compared to the AKM AK4493SEQ DAC used in the H390.

Like the H390, the H400 offers more digital inputs than analog ones. These include two coaxial (RCA and BNC) and three optical (TosLink) S/PDIF inputs, a USB port, and an ethernet port. The optical inputs accept PCM audio up to 24-bit/96kHz, the coaxial and ethernet inputs can handle up to 24/192 PCM as well as DSD64 (DoP). The USB input accepts 32/384 PCM data and DSD256 (DoP). The H400 can also play MQA 8X (352.8kHz/384kHz). A single coaxial (BNC) S/PDIF digital output that delivers data at 24/192 is available for those wishing to bypass the built-in DAC altogether. The H400’s digital inputs, except for the USB one, are capable of input sensing, which allows the amplifier to automatically switch to the active source when an audio signal is detected.

The H400 offers the same suite of digital inputs as the H600 does, specified at the same bit depth and sample rate. The two amplifiers differ on the analog front, however: the H400 has one balanced (XLR) and two unbalanced (RCA) inputs, whereas the H600 offers two of each. The H400 also has a pair of unbalanced (RCA) outputs, one fixed and one variable, which are said to have greater gain than those of the H390.

In addition to a new DAC, the H400 has an updated streaming platform that supports Apple AirPlay 2, Google Cast, Spotify Connect, Tidal Connect, and UPnP. And the H400 has received Roon Ready certification. Listeners can select music and adjust the H400’s volume setting using apps that support any of these protocols.

The H400 (and H600 as well) also works with the new Hegel Control app, which is available for Android and iOS. Functions of the app include input selection, volume adjustment, and play/pause control. In addition, the Hegel Control app incorporates Airable’s Internet radio and podcast catalogs. And it allows playback of locally stored music from media servers on the user’s home network.

As with other Hegel integrated amplifiers, a number of useful operational functions are available with the H400, such as setting the startup volume and the maximum volume level possible. Owners of newer TVs can use the TV remote to power up the Hegel and adjust its volume. Volume control by a connected USB source, such as a computer or streamer, is also possible. Additionally, most of the H400’s inputs can be configured as home-theater inputs, and thereby be fixed at a high volume level. Of course, this requires the source to have its own volume control.

System

The H400 replaced my resident integrated amplifier, a Bryston B135 SST². A pair of Nirvana Audio Royale speaker cables connected the H400 to my Monitor Audio Gold 300 5G speakers. Digital content was provided courtesy of a NAD C 565BEE CD player via an i2Digital X-60 coaxial cable, initially linked to a Bryston BDA-2 DAC, but later to the Hegel directly, to feed the onboard DAC. I also streamed from Apple Music on an iPhone SE to a Bluesound Node 2i streamer. An AudioQuest Forest TosLink optical cable connected the Node to the BDA-2, which in turn was connected to the H400 with Nordost Quattro Fil RCA cables.

For vinyl playback I used a Thorens TD 160 HD turntable equipped with a low-output Sumiko Songbird moving-coil cartridge mounted on a modified Rega Research RB250 tonearm. A Pro-Ject Audio Systems Connect it RCA CC cable linked the Thorens to a Pro-Ject Phono Box DS3 B phono stage, which was powered by a Pro-Ject Power Box S3 Phono outboard power supply. The DS3 B was linked to the H400 by Kimber Kable Tonik interconnects. I used generic RCA cables to connect the Hegel’s variable analog outputs to an SVS SB-4000 subwoofer. All electronics (except for the subwoofer) were plugged into an ExactPower EP15A power conditioner.

Analog performance with the Bryston BDA-2 DAC

To be able to assess the H400 purely as an amplifier, that is, to gauge its analog performance, I began my audition bypassing its built-in DAC and used the Bryston DAC instead.

The pioneering British trip-hop band Massive Attack has a penchant for working with talented female vocalists. Its 2003 album 100th Window (CD, Virgin Records 724358132120), featuring Sinead O’Connor, is one example. O’Connor’s soft crooning on “When Your Soul Sings” sounded delightfully intimate, floating serenely over the warm tone of the bass but remaining the focus of this highly atmospheric track. The H400 provided a black canvas from which the song emerged in great detail. Instruments were imaged distinctly on a spacious soundstage, with electronic effects spanning the front of the listening room.

The H400’s sound was clean and highly resolved but not so much that it could be called analytical. It was easy and enjoyable to listen to for extended periods without fatigue. It had a smooth, liquid character I found enticing. Top-performing solid-state amplifiers defy straightforward characterization because they impart essentially no sonic contribution of their own. And the closer the amplifier gets to the proverbial straight wire with gain, the more imperceptible it is and the harder to characterize. This is the sonic realm the H400 inhabits.

Now in the mood for some more female vocal music, I reached for Mazzy Star’s 1993 album So Tonight That I Might See (CD, Capitol Records CDP 598253) with Hope Sandoval (who, coincidentally, has also worked with Massive Attack). The acoustic guitar on “Five String Serenade” sounded full-bodied and weighty, though not unduly prominent. The periodic metallic splash of tambourine that punctuates this track emerged from just behind the left speaker, hanging in space on this reverb-heavy song.

Like Sinead O’Connor on “When Your Soul Sings,” Sandoval is the focus of this quiet tune, but her voice didn’t jump out at me; it remained at the plane of the speakers. The ethereal quality of Sandoval’s voice was fully captured in this recording, and the H400, with its vanishingly low noise floor, was the perfect instrument to communicate that vocal delicacy and lightness. Once again, the Hegel got out of the way, calling no attention to itself and leaving no sonic imprint of its own. If you want to hear your recordings, not your amplifier’s particular way of rendering them, you’ll love the H400.

“An die Hoffnung” (To Hope), op. 94, from Beethoven Songs (CD, Hyperion CDA67055), is an enchanting piece of music delivered with incredible power and dynamics by the German baritone Stephan Genz. This song begins gently with Genz’s calm, even delicate, delivery of the poem’s somber lyrics. In the background was the soothing tone of Roger Vignoles’s piano, its placid, clear notes trailing off into pitch-black space. The atmosphere changes abruptly on the last line of the opening stanza, “Hoffen soll der Mensch! Er frage nicht!” (man should hope, not question!), an impassioned, stentorian exhortation that catches the unsuspecting listener off guard—I was jolted from my seat at this point when I first heard this recording.

The H400 responded to this highly dynamic recording with such clarity and ease that I found myself listening to it at a higher volume level than I normally do. As I mentioned, this amplifier has a remarkably low noise floor—when I turned the volume up all the way with no music playing, I heard nothing but silence from the Gold 300s’ tweeters—so even at that loud volume, the H400’s delivery remained completely clean. And with power to spare, it sounded effortless. Quietness and effortlessness were among the qualities I most admired in the flagship H600. Its smaller sibling possesses them too.

I turned to a 1958 vinyl recording next, Camille Saint-Saëns’s Symphony No. 3 in C Minor, known as the “Organ Symphony,” performed by the Detroit Symphony Orchestra under the baton of Paul Paray (Mercury Living Presence 028948526017). The H400’s presentation of this album was dynamic and exhilarating. More impressive still was its presentation of another recording of this magnificent work, featuring the Boston Symphony Orchestra under Charles Munch (CD, BMG Classics 82876-61387-2 RE1). With this recording, the H400 was able to unveil Saint-Saëns’s masterpiece, the closing movement in particular, in all its awe-inspiring majesty. On both recordings, this amplifier had no trouble conveying the full breadth and power of the organ, sustaining impossibly deep bass in my listening room with ease and authority.

Performance with the onboard DAC

Once I had a good sense of the sound of the H400 with the Bryston DAC, I continued my listening using its built-in DAC, switching back to the external DAC from time to time for comparison. I began with “Faust Arp,” from Radiohead’s 2007 album In Rainbows (CD, TBD Records TBD0001). What I heard was whisper-quiet, impeccably resolved digital playback, indistinguishable from that I heard with the external DAC. Thom Yorke’s voice, his and Jonny Greenwood’s acoustic guitars, and the strings of the Millenia Ensemble were all sharply outlined across a broad soundstage, just as with the Bryston DAC. On “House of Cards,” the bass drum had a bit more impact through the H400’s own DAC than through the Bryston DAC. It stood out a bit more and had greater clout. Switching between the two DACs a few times, however, revealed that what had initially seemed like an appreciable difference was, in fact, rather minor.

I then listened to “Sleeping on the Blacktop,” the opening track on Colter Wall’s 2015 album Imaginary Appalachia (CD, RCA 19658-83001-2), again, switching back and forth between the two DACs. As before, the two DACs were equally transparent, but I heard a bit more space around Wall’s acoustic guitar through the Hegel DAC. On “Living in the Sand,” the first guitar note was a touch more pronounced through the Hegel DAC, but the difference was subtle.

To my ears, whether I used the H400 with its built-in DAC or with the external Bryston DAC had minimal effect on its sound. When I could tell the difference, I tended to favor the Hegel DAC. How reliably could I distinguish between the two? I’d love to take a double-blind listening test to find out.

Comparison

For another perspective on the H400 performance, I compared it with my Bryston B135 SST², which I’ve owned for more than a decade. While still in production, the B135 could be purchased with an onboard DAC and a moving magnet phono stage. It doesn’t have the streaming capabilities of the H400 and, at 135Wpc, is not as powerful. It does carry a 20-year warranty, though, far longer than the H400’s two-year warranty. Both the Hegel and the Bryston have gone a long way toward meeting the straight-wire-with-gain ideal, and both offer an incredibly quiet, highly transparent, neutral presentation. Where the H400 beats its Canadian rival is in sheer power and the sense of effortlessness that comes with it.

Listening to “m.A.A.d. city,” from Kendrick Lamar’s good kid, m.A.A.d. city (CD, Aftermath B001753602), I could certainly play it loud with the B135 but only up to a point; beyond it, the music started to “sound loud”—unpleasant. In contrast, the H400 played with a greater sense of ease, which was manifest even at high volume levels. I found I could play music louder with the Hegel—it was virtually inviting it—than with the Bryston, before discomfort set in.

In a smaller room, the difference in performance between the two amplifiers might not be very noticeable. But in a large room, listening at high playback levels, the H400 sounded better than the Bryston, its extra power and ability to remain composed at high volumes giving it the edge.

Conclusion

Hegel’s new H400 could easily be an endgame purchase for many listeners. It’s the ultimate all-in-one package, boasting features that are increasingly expected in modern integrated amplifiers. With its built-in digital-to-analog conversion and streaming capabilities, it can handle almost every function a potential buyer would likely need. If you listen to vinyl, you’ll have to add a phono stage, but buyers of amplifiers at this price point would be inclined to do that anyhow, I suspect.

Features aside, the H400’s sound was impeccable, its performance leaving me with nothing to criticize. Naturally, some listeners may prefer a different sound, but that doesn’t reflect any shortcoming on the part of the Hegel. With its copious amounts of power, incredible transparency, and smooth delivery, the H400 encouraged long listening sessions. If your priority is sound quality and you aren’t seduced by flashy designs that scream “look at me, I’m expensive!” you will find the H400 a compelling option.

It would have been interesting to compare the H400 with the H600. I suspect it achieves most of the performance of the flagship model at a considerably lower price. Unless you need the extra power of the H600, you’ll probably be equally served by the H400, a much better value in this case. If you’re looking for a top-of-the-line integrated amplifier with a state-of-the-art DAC, this newest member of the Hegel family is an easy recommendation.

. . . Philip Beaudette
philipb@soundstagenetwork.com

Note: for the full suite of measurements from the SoundStage! Audio-Electronics Lab, click here.

Associated Equipment

• Speakers: Monitor Audio Gold 300 5G
• Integrated amplifier: Bryston B135 SST²
• Subwoofer: SVS SB-4000
• Digital sources: NAD C 565BEE CD player, Bryston BDA-2 DAC, Bluesound Node 2i streamer, Apple MacBook computer running Audirvāna
• Analog source: Thorens TD 160 HD turntable, Rega Research RB250 tonearm, Sumiko Songbird MC cartridge
• Phono stage: Pro-ject Audio DS3 B and Power Box S3 Phono outboard power supply
• Speaker cables: Nirvana Audio Royale
• Interconnects: Nordost Quattro Fil (RCA), Pro-ject Connect it Phono RCA CC, Kimber Kable Tonik (RCA), generic USB
• Digital links: AudioQuest Forest (TosLink optical), i2Digital X-60 (coaxial)
• Power conditioner: ExactPower EP15A

Hegel Music Systems H400 Streaming Integrated Amplifier
Price: $6995
Warranty: Two years, parts and labor

Hegel Music Systems AS
PO Box 2, Torshov
NO-0412 Oslo
Norway
Phone: +47 22-60-56-60
Fax: +47 22-69-91-56

Email: info@hegel.com
Website: www.hegel.com