Georg Wilhelm Friedrich Hegel, was a German philosopher who lived at the turn of the 18th to the 19th century, and is considered by many to be one of the pivotal philosophers of western thought and the principals of idealism. His major thesis was that “the rational alone is real”, and he quoted, “Whatever is reasonable is true, and whatever is true is reasonable”.
Founded by Norwegian Bent Holder, Hegel Music Systems also seems to be driven to find reality and truth in the capabilities of their products. Mr. Holder explains that his company’s name does not originate from Hegel the philosopher, but from the band he once played in, the “Hegel Band” (I haven’t been able to figure out if that has any significant translation or meaning, but then again, my Norwegian is pretty rusty… ok, it’s non-existent). Regardless of the origin of the name, I’m sure that Georg Wilhelm would approve of the outcomes Mr. Holder has achieved in his approach to finding reality and truth in musical reproduction.
Something important to understand about audio amplifiers is that ALL of them create some level of distortion. Makes no difference the brand, or design, if it’s a phono preamplifier, a line stage, a power amp, etc. Amplification devices, right down to the transistor or vacuum tube level, distort the waveform found at their input to some degree, consequently creating an output that is different than their input. Most audio designers have for the most part, since audio amplifiers were invented, focused almost their entire being on reducing those potential distortions. There are all kinds of distortions that are measured – you’re probably most familiar with Total Harmonic Distortion (THD), but there’s also phase distortion, group delay distortions, amplitude distortion, frequency distortion, intermodulation distortion, and so on. Every one of these is something that a good designer has to deal with. And what’s worse, since every stage of amplification distorts the signal a little bit, the next stage distorts that distorted signal further, so things get progressively worse. The bottom line for the designer is how to neutralize these effects to the most minimal of levels thereby allowing the original waveform present at the input to be amplified and presented as faithfully as possible at the output.
One of the most widely used tools in the electronics trade to combat distortion is Negative Feedback which is a technique where a portion of an amplifier’s output is fed back to its input. This has the effect of lowering distortion and improving the linearity of the amplifier. Unfortunately it can also cause more harm than good because if it’s not properly applied it causes timing distortions between amplifier stages and can send an amplifier into an unstable condition and cause it to start oscillating at higher frequencies, and that ain’t good. In a class B or AB amplifier, different biasing techniques can reduce distortions as well, but they usually have to be very carefully implemented to keep bias currents at nominal levels that don’t damage semiconductors. Choice of power supply filter capacitors and how they are implemented along the power supply rails can make a difference as well. But, what if it were possible to figure out how to eliminate the distortion an amplifying device presents in the first place?
Back in the 1980’s the aforementioned Mr. Holter was a student of semiconductor physics at the Trondheim Technical University in Norway where he wrote a thesis revolving around the original design of transistors and how to cure the problems of distortion in the amplifier circuits of the day. He considered harmonic distortion to be public enemy number one. Holter’s main concern was that you could feed a simple signal to an amplifier and get back something different that was essentially the original signal plus the distortion added by the device. He also realized that implementing most of the classic theories to reduce distortion could cause other problems with the signal that could affect performance, like an amplifier’s damping factor (a measurement that describes how well an amplifier will control the cone or diaphragm of a loudspeaker) or its phase linearity. He founded Hegel Technology in 1988 and his thesis and resulting project evolved into what is today Hegel’s patented “Sound Engine” technology, now in a “Sound Engine 2” revision.
Without getting too buried in the weeds, Hegel’s Sound Engine utilizes an analog computer and comparator circuit in each stage of amplification. The analog computer takes a continuous “snapshot” of the signal, and inverts it, then compares it to the original waveform. Because the waveform is inverted, distortions that have been added appear as differences in the original waveform and are filtered out leaving the original waveform intact without distortion at the circuits output. This what is known as a “Feed Forward” (versus “Feed Back”) technology. It’s not necessarily a new concept – Peter Walker of QUAD fame utilized a Feed Forward style in his “Current Dumping” amplifier designs described in a seminal paper back in 1975 – but Hegel has brought it up to date with newer technology and implementation. You can learn more about the technology in some cool videos on Hegel’s website: https://www.hegel.com/en/technology/soundengine
So, after that preface, what does all this mean for performance and how Hegel’s amplifiers handle the music. Well, I’ve had a Hegel H120 integrated in residence for a few months now and have also pulled in an H190 with double the power of the H120 for comparison. The H120 is rated at 75W/channel at 8 ohms, while the H190 is rated at 150W/channel at 8 ohms. Both are stable down to a 2 ohm load. The 120 has a reported damping factor of 2000 while the 190 clocks in at 4000. Damping factor is essentially a measure of an amplifier’s ability to control drivers in a speaker; rise time gets a driver going quickly, but damping factor makes it stop, so the better the damping factor the better things like mid to deep base is controlled without ringing, lumpiness and weird overhang effects. They have networking capabilities and are software controlled, which can be easily upgraded with a connection to your home network. Both are current models. the H120 has driven Acoustic Zen Adagio’s, Wharfedale Linton 85’s, and currently, PMC Twenty 5/26i’s (more on the latter two speakers in upcoming reviews). My sources have been the usual culprits: My ever present SOTA Sapphire with Fidelity Research FR64fx arm and a variety of cartridges; a Sutherland Insight phono preamp set up for low output moving coils; either an Oppo 105 multi disk player or my new Yamaha CD-S1000 (which I am loving!); or streams from the web or my music server via a Bluesound Node. Cabling has all been Acoustic Zen, Supra, or some of my own designs, and optical connections from Apature.
To say that the Hegel’s are great amplifiers is woefully inadequate. The reality is, they are some of the cleanest, fastest, lowest distortion, always in control, with little sound of their own amplifiers I have EVER heard… and I’ve heard a lot! I’ve had a couple of Hegel amps in the past as well, and really enjoyed them, but this new, updated Sound Engine 2 variety surpasses the former amps by more than a fair margin. The sheer quality of the signal that drives whatever loudspeaker I’ve hooked up to them is above reproach. The Hegel’s just gets things right, and the lack of distortion is immediately apparent to anyone who loves music in their home. Reliable as well; I’ve had absolutely zero problem with the current Hegel amps reviewed here or with any other Hegel I’ve had in the past. And, I must apologize to all you folks who love your “vintage” amps but Hegel just makes them sound… old.
On familiar tunes, no matter the source, the Hegel lays out an astoundingly wide and deep soundstage with remarkable frequency response that is accurate and flat across the spectrum. Not only is its response of very high caliber, it is also stable. Some amplifiers have good frequency response at certain levels within their power envelope but may struggle to keep that integrity at others. They lose the frequency extremes at low levels or their highs shred your eardrums at high levels. Listening to the Hegel at low levels or at a roar is a remarkably similar experience. It also maintains complete control over whatever speaker it’s driving and never breaks stride or looses control of the woofers (something that older technology amps do a lot!).
On Dire Straits “Heavy Fuel”, the drums have snap and attack like the real thing and the amplifier digs out little details in the background that others just simply discard. The song “Wherever I Go” by Mark Knopfler and Ruth Moody from Knopfler’s album Tracker made me stop everything else and just listen because the music is just absolutely mesmerizing in a way that allows every instrument and tone to spill into the listening room with size, air, timbre, and just plain realism that other amps just can’t come up with. One of my favorite test tunes is “Crazy” from Seal. This gem of a tune features some bottom end kick drum layered with 20Hz synth tones in the last minute or so of the song I’ve heard sound like mud and mush, but with the Hegel they’re taut, punchy, gut thumping, and have tonality and real response, not just a booming mess. Another test is Peter Gabriel’s “Digging in the Dirt”; with this cut, it’s all about Tony Levin’s bass playing. Most systems make the sound garbled, incoherent, and with a “one note” bass quality akin to most car stereos. With a great amp, the notes themselves and the string plucks on Levin’s bass come through. With the Hegel they come to life. Every one allows you to hear the mastery of this incredible artist as he was intended to be heard.
When I fire up the vinyl Jimmy & Wes, The Dynamic Duo, I always remember why I love jazz. The virtuosity of Jimmy Smith at the organ and Wes Montgomery working over his guitar is mesmerizing on this recording, and through the Hegel it’s more captivating than ever. Not only are you given the ability to hear two of the greatest jazz players ever, but hear them in what is suddenly a more natural space where you can here through to the room they are in. Other, lesser amps just can’t articulate what’s buried in those grooves. You’ll find the same thing with a perennial favorite like Miles Davis’ “Kind of Blue”. I also have a penchant for romantic, sultry female vocals like Norah Jones, or Jane Monheit. When the more popular Ms. Jones sings “Turn Me On” from her album Come Away With Me, let’s just say that it perfectly conveys the effect intended by the lyrics. Monheit’s unbelievable purity of tone and timbre of her voice comes through like she’s in the room. The magnificent Eva Cassidy, who was snatched from this life way too early, singing “Songbird” or “Fields of Barley” from the album Songbird brings on such emotional floods it’s almost embarrassing; that voice… just incredible, and reproduced flawlessly.
One of my favorite classical recordings is a Telarc release of Yoel Levi conducting the Atlanta Symphony in Prokofiev’s First and Fifth Symphonies. The massed strings in this recording, especially in the performance of the Fifth are just huge. Without the right amplification in place, this can take on a “one note/one instrument” character because the distortions I talked about previously, get in the way of the articulation needed to properly convey the complexities of the players and the recording that actually captures the music and the composer’s intent. On the award winning BIS SACD of Beethoven’s Second and Seventh symphonies by Osmo Vänskä and the Minnesota Orchestra, the Adagio from the Seventh Symphony comes through with weight, detail, definition, and dynamics galore.
And, if that’s all too tame for you, slap on some ZZ Top, Wishbone Ash, Judas Priest, Rush, Joe Bonamassa, etc, etc, etc, and a Hegel amp will rock your socks off! “Whole Lotta Love” from Led Zeppelin II has a bass line from John Paul Jones that should rattle your guts, and the ability of the Hegel to delineate every howl from Page’s guitar, every wail from Plant, and every thunderous fill from the venerable John Bonham, just make you want to crank the volume up and flail your air instrument of choice with reckless abandon. It’s always fun to see what happens when folks have a familiar recording like this opened up like never before in front of them via a really great system – the smiles, head bangs, and fist bumps are ubiquitous. If you listen to a rockin’ tune from someone like Little Feat or maybe some Tower of Power, or even some Scorpions and it doesn’t get your tush movin’ while listening to a system with a Hegel in it, well, there’s just something wrong with you!
Now, my listening notes are mostly from sessions using the Hegel H120, but for the sake of comparison, I tried some other configurations just to make sure that I wasn’t gushing too much unfounded praise on the Hegel sound. So, I tried one of my favorite, classic power amps of all time that we happened to have on hand at the shop – the McCormack Power Drive DNA-1 Deluxe. The McCormack is almost three decades old, and what “vintage” should really be all about because it still holds its own against modern designs, it’s not just old. It did not disappoint. I have been lucky enough to have a pair of PMC Twenty 5/26i’s at my home for a few weeks now, and they are truly the best loudspeakers I’ve ever had in one of my own systems; I’ll have more about those in a future review, but bottom line, even though the H120 was playing beautifully through them, I thought the big PMC’s might benefit from more power. So, I carted the 150 Watt per channel McCormack to my lair and hooked the variable pre outs from the H120 to it. After letting it warm up a bit, it was immediately apparent that the McCormack is still a world class amp. I listened exclusively to “O Tannenbaum” from The Vince Guaraldi Trio’s A Charlie Brown Christmas (yes, that Charlie Brown Christmas!). This is a very recognizable recording to almost anyone, and it is actually a very good one. The instrumental spread on the stage is precise and very realistic with tons of space around instruments and a spectral balance that sounds about as real as you can get. The extra power provided by the McCormack created more “size” and body to the sound with outstanding bottom end extension and a warm, rich midrange presentation. There was plenty of air and space around instruments with natural timbre and exceptional, flat response across the spectrum. The DNA-1 would be a happy camper in any self-respecting audiophile’s rig to this day. Yet, there was just something about the Hegel. There’s a “purity” and natural sound to the Norwegian amp that is simply inescapable. So, with that in mind, I swapped out the H120 with an H190 which doubles the power output of the 120’s 75W to 150W, over the 2021 Christmas and New Year’s holiday weekends. The outcome? Everything the H120 does the H190 does in spades and ups the performance ante across the board, if that’s possible. The 190 gripped the transmission line PMC beauties and controlled every aspect of their performance like a marriage made in heaven.
In my experience, integrated amplifiers tend to have a coherence to their sound that sometimes even the best separate power and pre-amp combinations can’t match, maybe because of the lack of an interconnect or some sort of synergy in power supplies and circuitry. In Hegel, that coherence of sound is without peer, and that coherence of sound has essentially made me forget about separates for a while. Not saying that separates can’t be as good or maybe even marginally better, but with this level of performance, who cares! It’s no wonder that many speaker manufacturers are using Hegel amps these days as references and as tools to tune their products, and they are hailed as reference class products across the audio press.
Oh, and on top of all that, Hegel’s integrated amplifiers include outstanding DAC’s and network capabilities for streaming from all kinds of sources. The DAC sections utilize AKM DAC chips because they believe them to be the most natural and musical devices they can find, but Bent Holter and his team spend lots of time and attention on things like jitter and noise reduction as well. The H120 and H190 both sport one coaxial, one USB, and three optical inputs and I’ve utilized them all. Now, without opening the proverbial audiophile digital can of worms, I’ll tell you that all of them performed flawlessly and to be perfectly transparent, a majority of my listening to the Hegel’s has been via their digital inputs from my personal server based library. It’s just so darned easy to sit back and troll when you have hundreds of CD’s ripped into a server! I’ve had a number of different DAC’s in and out of my systems over the years, and many of the most advanced ones with multiple layers of oversampling or the latest DAC chips… well, didn’t really last long or truly impress me that much. Many become dry, glassy, and fatiguing over time. Some of my favorites have been ones that utilize NOS (Non Over Sampling) topologies with old TI 16bit or Analog Devices 20bit DAC chips. They just seem more natural, smoother and allow you to listen for hours on end and never get fatigued. The Hegel DAC’s perform in the same way. Never once have I had a desire to move to a different DAC while listening to the ones imbedded in the Hegel integrated’s. There are some folks that I’ve seen comment in forums and discussion groups about using external DAC’s that they deem better, but they are generally the same folks that comment on anything discussed not being good enough for them, so I’ll just say that you can certainly try other combinations, but to this listener there’s no need.
So, in the final analysis, it is obvious that Hegel has wrought a truly innovative answer to the questions of distortion. Even in casual listening, that they are so low in distortion, noise, or any other amplification artifacts, makes it obvious that they are very special products. The Hegel team has truly figured out how to “kill” distortions in their designs and quite honestly are leaving a number of other manufacturers in the dust with the purity and natural sound emanating from their amps, every one of which is a champion at their price point. From the entry level H95 up to the 300+ watt H590 behemoth, you get Hegel’s Sound Engine 2 technology, great features, network connectivity, a built in DAC, and sound second to none. As you ascend the product line you get more power, more dynamics, MQA support in the top two models, and more refinement commensurate with the price, but even the lower cost models will be an absolute revelation to almost every music lover. Yes, the price of entry is a little higher than some, but in terms of resulting sound, and in the context of most systems the Hegel amps will happily live within, they are a bargain, and for most of us normal mortals without trust funds or the income of oil sheiks, the Hegel’s could easily be the last amplification product you ever buy. They will bring your music to a new level of reality that you cannot escape. Their sound is so real, that old Georg Wilhelm Friedrich would certainly have one in his own system!
A short epilogue:
As I finish up this review, Eva Cassidy is singing “Over the Rainbow” through the H190 driving the PMC Twenty 5/26i’s… excuse me while I go dry my eyes.
