HEGEL H150 AMPLIFIER REVIEW
The Hegel H150 amplifier is a fully fledged, modern integrated design that features a Moving Magnet phonostage, onboard DAC, and line-level inputs. The sleek-looking amplifier is avaialble in black or white and will cost you £2750. Janine Elliot takes a listen for HiFi PiG.
Hegel, from Norway, makes some really simple-to-operate, good-looking and sounding audio; something I regularly see from the Scandinavian countries. Inside, it is not quite so simple, and the H150 full-width streaming amplifier (second up in the range, and succeeding the H120) with Moving Magnet phono stage is certainly full of technology. All that technology has its roots in the thesis Bent Holter wrote as a student at the Technical University in Trondheim in 1988. His written piece was about the design of transistors in amplifiers. Bent couldn’t see why, when we supply a signal to a transistor, it also produces distortion. Fighting distortion usually means there is deterioration in other parameters, such as the damping factor. He decided to break free from classic schematics used in amplifier designs for decades, and so developed a project that became the basis of what they call SoundEngine Technology. What this technology does is cancel crossover distortion found in all types of class-AB amplifiers. Our human ear is very sensitive to high-frequency distortion, so the patented SoundEngine technology cancels these high-frequency distortion components. The Hegel SoundEngine technology does not use negative feedback; rather, it uses local and adaptive feedforward technology if there should ever be any need for cancellation of distortion within the audio amplifier stages.
Of course, Bent Holter is also a musician (are there many manufacturers who aren’t these days?) and used to play in a rock-metal band called “The Hegel Band”, hence the name of the audio company. The band needed amplifiers for their concerts, so he decided to build them himself with help from Telenor. Today, the company’s products are sold all over the world.
BUILD AND FEATURES OF THE HEGEL H150 AMPLIFIER
The H150 is a full-width (17”) sparsely decorated amplifier available in either black or white; just a function and volume knob oneither side of a central OLED display. Note, it is not available in silver, and I felt the white version I had for the review really fitted well into my room décor; something very important to the company is that their HiFi should be part of the room and not an addition. With a thick curved front panel and notably thin amplifier depth of 35cm, there is no need to worry about fitting this one on shelves. The top is a perforated steel cover, so plenty of ventilation.
Just as in the previous H120, the Class A/B amplifier inside is only 75W into 8-ohms, but with a high damping factor of 2000 and stable operation down to 2-ohm loads, I didn’t find I was missing much. The H150 is powered by an ultra-low-noise toroidal transformer, plus high-speed capacitors.
Inside is a custom-designed, four-layered DAC inspired by their Viking CD player, based on an AKM chip-set. That got me excited, as I am a fan of AKM DACs. However, let me stress that the DAC chipset is just one part of the circuitry, so everything else is equally important. The digital side of the H150 supports streaming options such as Spotify Connect, Tidal Connect, Qobuz Connect, Google Cast™ Apple AirPlay, etc. Automatic firmware updates keep you ahead of the curve, and there is also uPnP.
The rear is where the action begins and ends. Along with an RCA and balanced XLR analogue line-level input, there is also an MM phono-stage (plus earth connection), something the H120 didn’t have. Digits are well catered for; 2 Toslink opticals (24bit/96kHz) with one TV-optimised, one coax (24/192), a USB-B, a network port, and a USB-A socket so you can connect your flash drive or powered hard drive. A coax-digital output is provided plus an RCA analogue variable output if you want to use the H150 as a preamp to your power-amp, or to a subwoofer, of course. A single pair of loudspeaker terminals completes the back, plus the IEC input to power it all up. The front also adds a headphone socket.
Apparently, this is a really easy amplifier to operate, and the instructions told me you can enjoy the H150 without reading the manual. Good, that saves me time. With input-sensing on digital inputs and streaming, it wakes the amp up and selects the correct source automatically, while the adjustable auto-standby saves energy after finishing listening. You can even connect your TV as popular TV-remote codes are pre-loaded, allowing volume and power control with your TV remote in case you lose the Hegel one. Each input can be set individually, allowing you to control the volume with any connected remote or multi-room streamer (and multi-room is offered directly in the amplifier, either via AirPlay, Google Cast, or Roon), and voice commands via Google Home or Apple Home are just a sentence away.
The main remote is the cute aluminium Hegel device for basic functions, or you can use the complimentary Hegel Control app, which also offers other intuitive input and volume control. You will really need that if wishing to play audio from a flash hard drive. I utilised the app for most of my dealings with the Hegel, though it is quite basic for my tastes.
A nice feature on the H150 is the “DAC Loop” function which allows you to upgrade the digital inputs of the amplifier with your own super-duper DAC and feed it back to the XLR analogue input in the Hegel, if the onboard digits don’t quite meet your high standards.
That Damping Factor
The damping factor is nothing to do with mould on your walls, but rather is a number that has often been used in amplifiers in HiFi circles for at least 70 years. Basically, the higher the number the better, and the Hegel’s “2000” is quite astounding! The damping factor is the ratio of the loudspeaker’s nominal impedance to that of the amplifier’s output impedance. The higher the number shows that the amplifier is better able to control the cone movement of the loudspeaker. Think of the loudspeaker driver as a motor (indeed, it is a motor…). If you apply voltage to a normal DC motor it starts revolving. If you do the reverse and turn the motor round by hand, then as a dynamo it creates the voltage. Think of your car alternator, or those lights on older bicycles that only lit up when you were pedalling! If you supply current to your loudspeaker, the cone pulses back and forth making the sounds, but it also acts as a generator when it slows down its vibration after the sound has stopped (it’s called back-EMF – like regenerative braking in electric cars). With low damping factors, that slowing down of the cone takes a longer time and sounds more “wooly”, and hence valve amplifiers generally have a lower damping factor (as they have higher output impedance – ohms). Solid state amplifiers tend to have a much tighter sound as that damping factor number is much higher (100-500 is a good number). So, with a figure of 2000 those ends of notes, especially in the woofer (as this one takes longer to physically stop vibrating) should be remarkably tight/accurate/precise. Of course, science isn’t as musical as our own ears, and many believe any number above 20 is actually sufficient. One also needs to consider cabling impedance and certain loudspeakers are harder to drive than others (The H150 will actually play down to 2-ohm speakers).
Interestingly, Bill, from Auden Distribution, who supplied the H150, did suggest to me using standard mains cabling, rather than after-market cables that Hegel feels can compress the sound – good news for any audiophile on a budget then.
Time to start listening.
SOUND QUALITY
My immediate observation from the amplifier was the fast and powerful bass-end, such as the rhythm from “Sleepy” from Canadian singer Domonique Fils-Aimé. With gorgeous vocals, percussion and tight guitars, the latter was also found on Joe Bonamassa’s “High Water Everywhere” recorded live at the Royal Albert Hall, London. This piece has two African sounding tom-toms on either side of the stage from two percussionists, reminding me of the technique on Adam and the Ants’ “Stand and Deliver” “Burundi drumming” from my youth. With very strong hall reverb, the guitars were fast with very tight initial transients. Whilst you might think that “tightness” would just be from the smaller wavelengths from the treble side, fast bass – such as the incredibly quick sounds from my Wilson Benesch “infrasonic generator” just show that the bass is equally essential for those tight starts. These first two tracks were via a 1TB hard drive plugged into the USB input, kindly supplied in the box just for me. The Hegel immediately selected the source, and the App allowed me to find the drive, the tracks, and then play them.
The H150 display is very simple, so don’t expect images or names of albums etc. It will, as standard, tell you the sample rate, source and volume level, though. Pressing “play” on the remote for 5” allows you to activate extra functions, but in common with Hegel philosophy, everything is kept as simple as possible for the user to enjoy the music and the looks, rather than concentrating on technical jargon and buttons. What I really love is that I can read the screen from a distance, unlike on some amplifiers I have reviewed this year! Of course, that screen can be dimmed or switched off if you feel the need.
The amplifier really excelled in its control, speed, soundstage and frequency response in “Run” from the French duo Air. Their music has a lot of different influences and encompasses electronica, space-pop, dream-pop, chill-out, ambient, and some progressive rock, amongst other idioms. With audible influences of Kraftwerk, Brian Eno and even minimalist Philip Glass, their music really does deserve a good listening to. “Run” has lots of ‘Enigma’-type vocal chords, making for a very diverse sound-picture. Only at times did I feel the lowest bass wasn’t quite handled with the accuracy of amplifiers costing considerably more; London Grammar’s “Hey Now” has a very prominent deep-bass synth, which at times my LS5/9s couldn’t show enough control from the amplifier. The damped guitar playing, though, was spot on, being really tight and lifelike.
The deep vocals on Melody Gardot’s “Moon River” were impeccably performed, buttered with smooth violin section. This was exceptionally musical.
Classical music, similarly, came across with control and emotion where required. Shostakovich’s Op.24 “Worker’s Song of Victory” (Malmo Opera Chorus) was emphatic with large vocals and strings, plus precision percussion. The Hegel H150 is a victory for the company and is referred to by them as the “Prodigy” as it certainly has much talent for £2750.
Phono and headphone listening was equally good. Rachmaninov 2nd Piano Concerto (Martino Tirimo, Philharmonia Orchestra) was surprisingly buoyant and bountiful on my very underrated Technics SL-02 turntable with and Ortofon MM cartridge. I did, however, have to push the volume up to at least 53% to get that unmistakable emotion out of the music, especially in the gorgeous 2nd movement (later ruined by Eric Carmen in “All By Myself” and endless others who couldn’t create such heavenly music as Rachmaninov!). Only the last phrase in the 1st movement couldn’t quite give me the force that more expensive standalone phono-stages can. But it was still good.
Eleanor McEvoy’s “Gimme Some Wine” (Chasing the Dragon), was very clear in this live studio recording at Air Studios that I was party to being part of a few years back. The Steinway piano is highly reverberant, and Eleanor’s wispy voice and acoustic guitar were very clear with an excellent soundstage. The accented first note in each bar of “Slow Hand” on the piano (Damon Butler) was fast and very natural. Eleanor’s quick change to electric guitar on this, the next track, was very clear, and I felt part of the studio again. Ends of notes and reverberations were just perfect. Even the gaps between tracks in this direct-cut disc were very real and organic, and the guitar distortion in “If You Had a Heart” was pin-sharp. On headphones, all the music I played was well presented, and the amplifier remembered the separate volumes for L/S and h/ph whenever switching. Nice!
QUIBBLES
There is no HDMI socket, especially as you can link up your TV remote to the Hegel. However, after speaking to Hegel they tell us that HDMI is purposefully not used as they believe it adds noise to the circuits, and that’s the last thing you want from an amplifier.
CONCLUSION
I knew I would be pleasantly surprised when I unpacked the H150: looks that would suit any room, and simplicity in operation that would even please my aged mother, but a great sense of knowing what really makes good music from the designers and engineers.
For £2750 you get a no-frills, sensible and highly musical offering that betters many of those fancy, glitzy, all-singing-all-dancing all-in-ones that might first tempt your wallet.
Have a listen, you will enjoy the music, and the fact that you haven’t actually spent a lot of money.
AT A GLANCE
Build Quality:
Beautifully simple with lovely curved frontage and good build
Sound Quality:
Excellent fast bass and controlled ends of sounds
Value For Money:
£2750 for just 75W might not seem great, but you never feel short of power, and the sound from digital, analogue and phono sources make this a highly good-value fully functioning amplifier
We Loved:
Fully functional all-in-one
Depth and tightness of sound, particularly in lower frequencies
Good performance of all types of music
Fast transients
We didn’t Love so much:
App is a little too simple for my taste, though some will prefer this approach
I’d have liked to see an HDMI input, but I now understand why HEGEL chose not to include one
Elevator Pitch Review: I have always loved HiFi and furniture from Scandinavian countries. It just looks so good, and in terms of sound quality, HiFi products that come from there are now leaps and bounds better than the (beautiful-looking) Danish B&O from my youth. Yes, sometimes beauty and sound quality don’t go hand in hand, but Hegel have nailed that one. Simplicity of design and operation, and a surprisingly musical performance. If you don’t have time for operation manuals or complicated apps, and just want to relax and listen to your music, then Hegel should be on your radar. And it comes in white; lovely!
Price: £2750, available in white or black
Janine Elliot
SUPPLIED BY AUDEN DISTRIBUTION
SUPPLIED SPECIFICATIONS
Power output: 2x75W into 8 Ohms @ 1kHz 1% THD , 100/120/230V AC
Minimum load: 2 ohms
Analog inputs: 1x Balanced (XLR), 1x Unbalanced (RCA)
Phono input: 1 x Unbalanced (RCA) for Moving Magnet (MM)
Digital outputs: 1x Coaxial S/PDIF – 24/192
Digital inputs: 1x Coaxial (RCA) S/PDIF – 24/192, 2x Optical S/PDIF – 24/96, 1x USB B- 24/192, 1x USB A 2.0 – USB Drives, 1x Network – 24/192
Line level outputs: 1x Unbalanced variable (RCA)
Streaming: Spotify Connect (Lossless), Tidal Connect, Qobuz Connect, Apple Air- Play, Google Cast, airable Internet Radio and Podcast, UPnP (Roon Ready pending certification)
Streaming formats: MP3, WAV, FLAC, ALAC, AIFF, AAC, PCM, Ogg
Frequency response: 5Hz-100kHz
Signal-to-noise ratio: More than 100dB
Crosstalk: Less than -100dB
Distortion: Less than 0.01% @ 50W 8 Ohms 1kHz
Intermodulation: Less than 0.01% (19kHz + 20kHz)
Damping factor: More than 2000 (main power output stage)
Dimensions/weight: 43 x 31 x 8 cm (WxDxH), 9.5 kg
Dimensions/weight US: 17 x 12.2 x 3.15″ (WxDxH), 20.9 lbs
