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

In “Big Yellow Taxi,” from her 1970 album Ladies of the Canyon, Joni Mitchell sings, “You don’t know what you’ve got till it’s gone.” I think this comes as close to a universal truth as it gets. It’s when we get sick, isn’t it, that we’re reminded how much we take our health for granted; when the power goes out that we become aware of how much we rely on power.

An analogous truism is that you can’t know what you’re missing if you’ve never had it. A case in point: soon after I began my audition of Hegel Music Systems’ H600, their new flagship integrated amplifier-DAC ($12,500, all prices in USD), I came to realize what the missing element in my system had been. It was an epiphany.

Description

Hegel began work on their next generation of integrated amplifiers three years ago, so I expect we’ll see the rest of the lineup updated in the near future. The H600 incorporates technology trickled down from Hegel’s P30A reference preamplifier, which impressed Jason Thorpe, who reviewed it in January, and boasts a redesigned DAC section and an updated, flexible streaming capability.

The decision to implement a new digital-to-analog converter was born out of necessity. If you’ve read Hans Wetzel’s review of the Hegel H590 integrated amplifier and Doug Schneider’s review of the H390 integrated amplifier, you’d be forgiven for asking why Hegel decided to mess with a DAC section that was a standout feature of these two models. This was done for both pragmatic and technical reasons. The DAC sections of those amplifiers are based on the 4493 chip from Asahi Kasei Microdevices (AKM). COVID-related supply-chain issues, however, and a fire at the AKM factory in Nobeoka City, Japan, disrupted availability of the 4493 and forced Hegel to find new DAC solutions to secure production. A converter implementation based on the ESS Sabre 9038Q2M chip was ultimately selected as the most favorable solution. As a bit-perfect design, the Sabre DAC does not resample the incoming signal. “The new DAC implementation in the H600 has such high resolution that it is a significant improvement over the H590 and in many ways the HD30,” the Norwegian company claims.

For digital playback, the H600 has two coaxial (RCA and BNC) and three optical (TosLink) S/PDIF inputs, a USB port, and an ethernet port. The optical inputs can accept PCM audio up to 24-bit/96kHz, while the coaxial and ethernet inputs can handle up to 24/192 PCM as well as DSD64 (DoP). The USB input supports 32/384 PCM and DSD256 (DoP). Additionally, the H600 handles MQA 8X (352.8kHz/384kHz). Except for USB, all digital inputs have input sensing, which turns the H600 on when it detects a signal and switches to the active input.

For analog playback, the H600 has two sets of unbalanced inputs (RCA) and two sets of balanced inputs (XLR), as well as two pairs of analog outputs: one fixed, one variable. Both outputs are RCA. I used the variable output to connect an SVS SB-4000 subwoofer that was reserved for watching movies. A fixed-level BNC digital output is also available.

Hegel describes the H600 as a mini P30A preamplifier because it uses the latter’s ultra-silent volume attenuator. In fact, they go so far as to claim that the new volume attenuator is the H600’s single biggest improvement over its predecessor, the H590. When I asked Anders Ertzeid, Hegel’s vice president of sales and marketing, about this, he conceded that while it is an improvement, the fully discrete gain stage in the P30A is still better. The preamp section’s voltage-amplification board features new transistors and has been upgraded for all inputs. Furthermore, the balanced analog inputs are now constructed using better internal components.

The H600, Ertzeid explained, shares much of the same basic layout as the H30A, Hegel’s reference power amplifier (reviewed favorably by Jason Thorpe in April on SoundStage! Hi-Fi). However, that’s where the similarities end. Most of the trickle-down technology in the H600 comes from the P30A. Power output is rated at 303Wpc into 8 ohms, nearly doubling to 590Wpc into 4 ohms, which is slightly more than the H590’s output with these loads. The H600 is a dual-mono design, with 12 power transistors per channel. This massive output stage is stable into a 2-ohm load, meaning it will drive pretty much any speaker you connect to it. Hegel’s patented SoundEngine2, an error-correction circuit whose purpose is to eliminate the crossover distortion inherent to class-AB designs, is also employed. As with the H590, distortion is less than 0.005% at 50W into 8 ohms at 1kHz. Damping factor is huge, greater than 4000, guaranteeing that this beast will be able to control drivers with an iron grip.

The updated streaming capability of the H600 includes support for Apple AirPlay 2, Spotify Connect, Tidal Connect, and UPnP/DLNA. Roon Ready certification was pending as I was completing this review. Hegel says the H600’s new streaming platform allows for future upgrades such as Qobuz Connect.

Measuring 6.7″H × 16.9″W × 17.5″D and weighing 48.5 pounds, the H600 is nearly identical in size and weight to the H590. It’s also styled similarly, except that the top cover is now thicker and has milled cooling vents. The control knobs are also larger and feature new rotary encoders that improve their feel. The OLED display was easy to read from my listening position; it can be switched off if desired. Overall, the H600 feels solid, as one expects of an amplifier costing $12,500. With almost no exceptions, Hegel products look clean and minimalist—perhaps a bit bland for consumers who want their pricey toys to look the part. As an owner of a decidedly unflashy Bryston amp, I appreciate Hegel’s utilitarian aesthetic. To me, it gives the impression of a company more focused on sound than on appearances.

Like the H600 itself, the all-metal RC8 remote is sturdy and substantial and is of commensurate quality. This remote offers rich functionality for adjusting the amplifier’s settings. For example, each time the H600 is turned on, it normally returns to the volume setting at which it was last used, but it’s possible to set a maximum startup volume so you don’t get a jolt when you power it up. An absolute maximum volume can also be set. Remote controls of some new TVs can be programmed to turn the H600 on and off and adjust its volume. It’s also possible to configure automatic input selection and automatic power-on.

System setup

The H600 replaced my Bryston B135 SST² integrated amplifier for this audition (discontinued; $4695 when available) and was connected to a pair of fifth-generation Monitor Audio Gold 300 floorstanders with Nirvana Audio Royale speaker wires. My NAD C 565BEE CD player was linked via an i2Digital X-60 coaxial cable to a Bryston BDA-2 DAC, which in turn was wired to the H600 with Nordost Quattro Fil RCA cables. Additional digital content came courtesy of a MacBook computer running Audirvāna and connected to the BDA-2 or H600 with a generic USB cable. My analog source was a Thorens TD 160 HD turntable featuring a modified Rega RB250 tonearm and a Sumiko Songbird low-output MC cartridge. A Pro-Ject Audio Systems Phono Box DS3 B phono stage (using a Power Box S3 Phono outboard power supply) was connected to the Thorens with Pro-ject Connect it Phono RCA CC cables. The DS3 B sent analog data to the H600 through Kimber Kable Tonik interconnects. All electronics were plugged into an ExactPower EP15A power conditioner/regenerator.

Sound with the Bryston BDA-2 DAC

I began this review by playing music through my Bryston BDA-2 DAC, which was connected to one of the H600’s line-level inputs. I wanted to assess and compare the Hegel’s capabilities strictly as an integrated amplifier. Later, I would engage the H600’s onboard DAC to gauge the capability of its digital section.

My new listening room, in a detached suburban Toronto home, has been a challenge to optimize. It is much larger than the listening room I had in the downtown Ottawa apartment where I lived for more than a decade, and it has taken some time to get to a point where I’m (mostly) happy with the sound. Here, my speakers are farther apart, and I sit 3′ farther away. Music is therefore presented on a grander scale and evokes a greater sense of space, but it takes higher playback levels to sufficiently energize the larger room.

In the introduction to this review, I said I had an epiphany when I started using the H600 as it exposed a missing element in my system. What was that missing element? Evidently, power. Coming from someone who owns a Bryston integrated amplifier, this might be surprising, given the Canadian company’s reputation for producing massively powerful amps. Until the H600 arrived, I had never doubted the Bryston’s power sufficiency. At 135Wpc it can play as loudly as I can tolerate, even in my new listening room. But after comparing it with the Hegel, it was apparent that the Bryston wasn’t nearly as effortless in its delivery. The H600 has power to spare, which enhanced the listening experience and made it more enjoyable.

When a new piece of gear shows up and you start listening to music you haven’t played in a while just to hear it on the new component—that’s a pretty good indication the product is special. In auditions, to better evaluate component performance, I listen to music I know well. With the H600 in my system, I was also reaching for albums I don’t normally use; I just had to hear them on the Hegel.

Björk’s Medúlla (CD, Electra 62981) was one such album; my normal go-to is her album Homogenic. On “Where Is the Line,” the Icelandic Choir emerged convincingly deep, reaching well behind the plane of the speakers. About a minute and a half into the song, the choir, on the left, starts whistling. The H600 delivered this passage so vividly that I stopped taking notes and looked up. Rahzel’s potent beatboxing and vocal escapades left me shaking my head in awe. I could not imagine how the sounds he produced were even possible. One of the most interesting aspects of this track is the juxtaposition of beatboxing with a classical choir. Rahzel appears on several tracks, including the closer, “Triumph of the Heart,” and he brings an interesting element to the percussion throughout Medúlla. The H600 handily peeled away the layers in this dense production and teased apart every detail and, most impressively, did so compellingly at any volume. I spent much of my time with the H600 at higher volumes than usual. This was due, in part, to the size of my listening room, as I mentioned, but it was also because the H600 never became disagreeably loud. Its sound remained smooth and fluid, inviting high playback levels.

After the frenzied “Where Is the Line,” Björk and the Icelandic Choir drastically reduce the tempo in “Vökuró.” The H600 conjured Björk up front and center, the crystalline clarity of her enunciation accentuating her presence in the room. Individual voices were projected distinctly around her across a wide stage. The ability of the Hegel to consistently convey this level of detail so readily and naturally was uncanny.

I’ve been listening to more classical music over the past year and was eager to hear one album in particular on the H600, a recording of Chopin’s nocturnes and impromptus by the Canadian pianist Angela Hewitt (CD, Hyperion SACDA67371/2). I hadn’t heard this record in some time and was immediately struck by the clarity of the piano. As with Bjork’s voice in Medúlla, the piano tone in this recording was so pristine I felt compelled to play it loudly. I took liberties with the volume, and the H600 happily obliged, amplifying the piano and expanding the space about it. It gave me more of everything I wanted to hear and spared me the hardness and distortion that arise when less powerful amplifiers are pushed too far. Like any amplifier, the H600 has its limits, but in this audition, I never even approached them.

Recorded at the Reitstadel in Neumarkt, Germany, this disc has incredible presence. The acoustic space captured in the recording was faithfully reproduced by the H600, sounding large but not cavernous. Hewett’s grand, true to its name, loomed large, full and powerful in its lower registers, sparkling radiantly in its upper registers. Pieces like the Nocturne in C-sharp and the Nocturne in F were delivered with such power, it was downright intimidating. I didn’t intend to but ended up listening to this two-CD set in its entirety.

Recorded piano music is notoriously difficult to reproduce well. At the same time, it’s easy to be critical of piano recordings: most listeners have heard a piano in person and have set expectations of how it should sound. I do too, but in Hewitt’s Chopin, played through the H600, my expectations were fully met.

I’ve been using Jerry Garcia and David Grisman’s Shady Grove (CD, Acoustic Disc ACD-21) in my reviews for years. Shady Grove introduced me to a genre of music I knew little about but appreciate more and more, and although my musical interests come and go, this is a disc I always return to. It is well recorded, and with the right gear, it is utterly convincing—it’s all happening right there in front of you. A cover of Mississippi John Hurt’s “Louis Collins” is a great example of this. Through the Hegel, it sounded as good as I’ve ever heard it. Everything was exceptionally clean and remained so as I turned the volume up. And up. The acoustic guitar was full-bodied and rich; the mandolin, crisp and clear, the notes popping from its strings. The same can be said for the sonic splashes issued by the brushed cymbals. The musicians were outlined sharply across a wide, though not very deep, soundstage. What I noticed most with the Hegel was the space around the instruments. I don’t recall perceiving this space so clearly before.

On “Be Your Husband,” from Jeff Buckley’s Live at Sin-é (CD, Columbia Records C2K 89202), the first thing I noticed was Buckley’s hand claps—they popped out at me, sounding eerily real at the front of the room. Live at Sin-é is well recorded, and the H600 presented it immaculately. Against the H600’s dead-quiet background, audience sounds and glassware clatter in that café, as the show was about to begin, came to life in startling realism. I was immediately transported to that venue and could sense the charged pre-show atmosphere viscerally.

Over time, it became clear that everything the H600 did was effortless. It could produce high output levels without clipping, which induced me to play loudly, as I mentioned. But it was also effortless at levels just above a whisper, where despite the smaller soundstage, it was still amazingly revealing. I took full advantage of this, and began extending my listening sessions, playing softly deep into the night (and, often, early morning).

Having experienced the H600’s unstrained presentation, I began to reconsider how much power I really need in my listening room. My B135² can play loudly enough, but it can’t match the relaxed demeanor of the H600. Bryston’s 4B³ 300Wpc power amplifier probably can. It would certainly have made for a fairer comparison.

Sound with onboard DAC

A major feature of the H600 is the onboard DAC, and I spent some time experimenting with it. On “Take It with Me,” from Tom Waits’s Mule Variations (CD, Anti-/Epitaph Records 86547-2), the Hegel’s DAC exceeded the BDA-2 in transparency and immediacy of presentation—not because it sounded any closer, but because it had so much more detail; the performers seemed to be in the room with me. Compared to the BDA-2, the lowest registers of the upright piano had additional weight, giving the instrument a more powerful presence, and Waits’s gruff baritone had coarser grit. Both the Bryston and Hegel DACs were detailed, but as I switched between them, I found the Hegel DAC consistently offered more see-through clarity. Hans and Doug were thoroughly impressed with the AKM DAC in the H590 and H390, and I was every bit as impressed with the Sabre DAC in the H600.

Other recordings, such as “She Moved through the Fair,” from Loreena McKennitt’s Nights from the Alhambra (CD, Quinlan Road QRCDDVD2-110-N), suggested that the Hegel and Bryston DACs were more similar than different. In this album, they were virtually indistinguishable in soundstage and tone of vocals and instruments. Still, the Hegel yielded a touch more space, a greater sense of air. The difference was subtle, though, and I had to alternate between the two converters several times to be sure of it.

I had a similar experience when I used a MacBook computer to play the Finale from the Engegård Quartet’s recording of Haydn’s String Quartet in D, op. 76, no. 5 (16-bit/44.1kHz AIFF, 2L Recordings). I also have a DSD128 copy of this piece of music, which unlike the BDA-2, the H600 can convert. (A sampling frequency of 352.8kHz reassuringly appeared on the Hegel’s display when the file loaded.)

I fed the AIFF file to both DACs, and what I heard largely mirrored the impression I had from listening to the Loreena McKennitt album. Specifically, I found both DACs to be highly resolving, to produce sharp transients from the violins, and to preserve the rich tone of the cello. Switching back and forth between the two DACs, the music seemed to emerge from a quieter background with the H600, and the instruments seemed more distinctly separated. Again, the performance difference was slight, but I preferred what I heard from the Hegel.

Comparison

The Bryston B135 SST², an integrated amplifier I’ve owned for nearly a decade, is rated at 135Wpc into 8 ohms, not nearly as powerful as the H600. It also lacks Hegel’s streaming capability. But, of course, when it was available, even including the optional internal DAC (a $1395 add-on), it was less than half the cost of the H600.

The B135² is commendably quiet and transparent, and much like the H600, it is remarkably neutral. Where the Norwegian integrated pulls away from the Canadian integrated is in its effortless presentation at high output. When I play the Bryston loudly, the sound can become a touch hard and uncomfortable, especially after extended listening. That never happened with the Hegel. If I were still living in an apartment, this would be less of an issue, but in a large listening room, the benefit of that extra power is undeniable. Medúlla, for instance, became unpleasant when I pushed the B135² too far; I never found where “too far” was with the H600. With no discernable distortion at high volume, however loud the music was, it never seemed so. It just sounded big, not loud.

That the H600, with more than twice the power of the B135², should handle high-volume playback with greater ease is to be expected, of course. What surprised me was the Hegel’s superior resolution and jet-black background at low volumes. As quiet as the Bryston was, the Hegel proved to be quieter still. This allowed tonal texture and delineation to emerge even at low volumes, as amply demonstrated by Angela Hewitt’s piano in the Chopin nocturnes. If you’ve got a big room or highly inefficient speakers (or both), you need power, and in this case, the scale is decidedly tipped in the Hegel’s favor. But even at low volumes, as I’ve mentioned, the H600 still pulls ahead.

Conclusion

The Hegel H600 is an exceptional integrated amplifier. Using the Bryston BDA-2 DAC I was able to compare the H600 and B135 strictly as integrated amplifiers and found the former superior—effortless and pristine at any volume. Remarkably, Hegel includes with this outstanding amplifier a topflight DAC that can easily rival external DACs costing thousands of dollars. This is the finest integrated amplifier-DAC combination I’ve heard in my time as a reviewer. At $12,500, the H600 isn’t cheap, but I suspect it would cost at least as much, probably more, to find another combination of integrated amplifier and DAC, whether as one or two units, that could outperform it.

Before the H600 arrived, I didn’t realize how much better my stereo could sound. It’s rare for a product to make me question my own system and to recognize that I am missing something. The Hegel has done just that.

. . . 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.
• 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 H600 Integrated Amplifier–DAC
Price: $12,500.
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