hen few years ago most companies „upgraded” their USB converters/USB DAC abilities from 16bit/48kHz to 24/96 few decided to resist this trend. Maybe you remember the UD-1 Pro D/A Converter by King Rex? It used Burr Brown PCM2702 chip, even then already outdated. And yet it offered an amazing performance which I described in my review getting myself „under fire” from those „High Fidelity” Readers who appreciated only cutting edge solutions.

It turned out that I wasn't the only one who truly appreciated such „outdated” solutions as Bent Holter, an engineer from already renown, although still fighting for its place on the market, Norwegian company Hegel, talked during presentation on High End Show in Munich about how an older generation, synchronous chip, if properly implemented, would sound much better than a newer generation, asynchronous one.

Each manufacturer though, has to follow and fulfill market's or customers' expectations. And the trend on the market has been recently clear – an ability to play high-resolutions files seems a must (the higher the resolution the better). And, in theory, it makes sense. Today's standard requires that D/A converters accept PCM signal of up to 24/192 resolution. Manufacturers who want to impress potential customers offer DACs that accept 32 bit/764 kHz PCM signal and up to DSD256. Music servers made today have to fulfill the same requirements to be truly up-to-date.

It seems that HD30 has been created as an answer for customers' demands. Just like another, quit fresh product - Naim NAC-N 172 XS, Hegel is something even more than just a D/A Converter. In fact HD30 could be described as:
1. A streamer – it sports an Ethernet port and so it can play music streamed from network.
2. A D/A Converter – there are as much as six digital inputs, including three TOSLINKs, RCA, BNC (all S/PDIF) and AES/EBU (balanced version of S/PDIF).
3. A preamplifier – a digital one (with only digital inputs and digital volume control) but still.

So how should we call this device? I guess that over time some new classification of audio products will be introduced/agreed upon, but for now there isn't a widely accepted one. Naim chose a simple solution for their NAC-N 172 XS, a device with exactly the same functionality as Hegel – they called it a streamer, preamplifier and D/A Converter in a single body.

And yet, Naim puts this device among other „Stereo Preamplifiers” and starts its description with: „For a start, the NAC-N 172 XS is a very high performance and inherently musical preamplifier”. Only then they also name it as: „streaming preamplifier”, pointing out its primary function – first of all it's a preamplifier with streaming function. Manufacturer calls this functionality: „DLNA Digital Media Renderer”. Streamer's capabilities are limited to: PCM (WAV, AIFF), FLAC, Ogg and mp3 files with maximum resolution of 24 bits and 192 kHz. Signal might be delivered via Ethernet ports or using AirPlay.

Connecting a DAC to a system seems nothing special at all, nothing to elaborate about. But obviously for creators of HD30 the DAC function is the most important one and thus it is called so. This review is a world's premiere of this device.

HD30 worked as DAC in my reference system with two digital sources: Ancient Audio Lektor AIR V-edition CD Player and Chord Red Standard Mk III. Signal was delivered using Siltech Eagle Eye 75 Ω digital cable. My trusted HP Pavilion dv7 with Windows 8.1, 8 MB RAM, 128 GB SSD + 320 GB HDD and Jplay software player worked as an alternative source. DAC was powered using Crystal Cable The Absolute Dream power chord.

Comparison between balanced (XLR) and linear output was performed connecting both directly to the inputs of my Soulution 710 power amp. For both connections I used Acoustic Revive interconnects: RCA-1.5Triple C-FM and XLR-1.5Triple C-FM.
Hegel's preamplifier section was assessed via connecting it directly to two power amplifiers: Soulution 710 and Accuphase P-6200, and later using two preamplifiers: Ayon Audio Spheris III and Accuphase C-3850.

I've worked in audio industry for the last 20 years. When I worked in a recording studio and with concert sound systems I used to think that describing sound was easy, that everybody spoke the same language and appreciated the same sound features thus easily separating “good” sound from a “bad” one. Over time I learned that most of my friends and professional colleges couldn't hear some things or just wanted not to hear them. Also vocabulary used to describe sound was rather limited thus not allowing to convey full information about it.

In this context entering the world of a home audio systems was very exciting as I finally could use tools to describe what I heard that were unacceptable in “pro audio” world. But this initial delight was only temporary as I realized that despite the fact that vocabulary describing hi-fi had been developed for 50 years there was still no one standard language that would allow to create a description that would be understood in the same way by all.

Listening to HD30 this old realization came back to me. Every now and then I receive emails from our Readers who claim that Hegel products often offer harsh or bright sound. When faced with such opinions that contradict my own experience with Norwegian devices I simply don't know what to say. I can hear something totally different and I would never say that Hegel sounds “bright”, or “harsh”. So when listening to HD30 I also tried to find a reason of such a different perception of Hegel sound by some people. It is hard to say whether I found the right ones, but let me give you some suggestions that might be useful for you next time you listen to one of their products.

Let me start with a statement that Hegel amplifiers offer darker sound than HD30. What I mean by that is that the latter delivers amazingly clean midrange, especially its upper part, which forbids us from perceiving this sound as “warm” - which is how I perceived H70, H100 and H200 (and a pre+amp system I’ve reviewed once for Polish „Audio” magazine). More careful analysis led to discovery that in fact the general tonal balance was very similar in all these devices and what made a difference was the quality of (upper) midrange – HD30 performed in this area better than any other Hegel component I knew.

This Converter delivers very open, clear, dynamic sound. Its presentation is remarkably “civilized” - just a few years ago I wouldn't have used this description for any digital device and today it can be used to describe more and more of them. This level of clarity of the sound combined with impressive dynamics could turn some lesser quality systems or those with poor tonal balance into “screamy” ones. When one delivers to loudspeakers a signal very rich with information but not a very clean one, or with some shifts in tonal balance, or there is some problem within a system with balance between resolution and richness of the sound, then the result – sound coming from speakers, might be a bit too “heavy” in the upper midrange.

But if one uses HD30 in a well performing, well balanced system using unbalanced cable and an external preamplifier (I'll get back to that in a moment) one should hear a smooth, creamy sound with w wonderful, open midrange. As I already said – this is an unusually “civilized” sound without even so much as a hint of any harshness or brightness. Whole range is quite rich, including bass that is also nicely extended and properly defined right to the very bottom.

There simply can not be any harshness in the sound because HD30 does the same thing as all Hegel products – it smoothens out the attack phase. I remember CD and SACD Players made by Wadia in their best period. If I didn't know any better I would have said that Wadia just released a new product. These Players offered quite a characteristic performance, but it was a very enjoyable one. I think they could be a main source in many systems still today.

HD30 follows old Wadias' track. It delivers a “modern” performance, meaning that it isn't either “tube” nor a “solid-state” one. When I compared it with tube output of my Lektor CD Player I couldn't really tell that these two devices used different technologies. Yes, the Ancient Audio CD Player is a better digital source. But having a chance to compare these two sources directly in the same system I can boldly claim that the difference is surely not a great one.

CHOICES

XLR vs RCA

But to achieve this level of performance one has to connect Hegel properly. My experience tells me that most devices offer better performance when connected with RCA cables. The idea behind balanced devices and balances signal transfer is surely a great one and I wish it could be properly implemented some day. Unfortunately the theory behind it assumes two identical halves of the signal and in real live they are never exactly the same.

It might be one of the reasons why Hegel might sound a bit harsh sometimes. The XLR connection, regardless of the usage of a preamplifier or driving directly a power amp might result in a bit “harder” sound. I can even understand why some might like it. But the Hegel itself offers a bit rounded, smooth attack and pushing it towards this “harder” sound changes its character a bit. In my opinion it contradicts the general concept of the sound proposed by Hegel – it is surely a specific sound but a well balanced one.

Preamplifier vs direct connection

While a choice between RCA and XLR introduces only a slight modification of the sound, using an internal preamplifier means a more profound sonic change, in my opinion it is a change for worse. One of the aspects that surely got worse was imaging – a very good one with external preamplifier, and much less precise, palpable with internal one. Upper midrange looses part of its clarity and expressiveness while emphasis shifts towards treble. That's not how I like my music played and I believe that a classic, analogue preamplifier is able to provide a better sound quality.

You have to remember the context here – I compared Hegel with the Ayon Spheris III preamp that costs 120 000 PLN in a system with Soulution 710 power amplifier that added another 150 000 PLN to the bill. I guess that when working with power amp from adequate price range difference difference between HD30 and preamplifier will be much less significant and this Hegel's functionality will be highly appreciated by its owner.

HD30 when offered a chance delivers a true high-end performance. Sound is rich, dense even, with open midrange and no emphasis in treble area. And I mean even with far from perfect recordings like Michael Jackson's Xscape or beautiful Bumerang album by Kortez. On these albums there is a lot of compression on vocals so it is easy to present them in a bright/harsh fashion and to emphasize sibilants. Hegel never ever does that.

Before I start to summarize this review I'd like to mention one more key advantage of this device. I had to try really hard not to mention that before but I did it on purpose so that you could better understand characteristic of HD30's presentation. But to give you a full picture I need to mention finally that this new Hegel's true strength is spacing – huge, convincing soundstage. This is one of the advantages usually attributed to turntables and pretty rare when it comes to digital sources (dCS and Ancient Audio players are among few exceptions from this rule). Hegel skilfully combines a rich acoustic surrounding of instruments with general acoustics of the recording. At the same time it greatly presents consequent layers of the soundstage from the front to the back. It's not about how any of these features is great by itself, what matters is that they plays a great part in creating a wonderful music spectacle – I was truly impressed.

For example on Kortez album they created a huge space surrounding listener using just stereo speakers (an effect similar to the one obtained once with Qsound system). With Hegel I could feel this dense, large space around me – it was even bigger than with Lektor AIR. Sounds seemed to be sustained bit longer which made acoustics less “dry”. Even on mono recordings instruments breathed like with high quality analogue sources.

Summary

Digital technologies are being constantly improved and progress is quite significant. And so HD30 performs equally well as the old Wadia Players and falls really not far behind today's twice as expensive. It does not offer as rich lower midrange as those and not so holographic imaging. But the soundstage it creates, the spacing is remarkable. It might work as a preamplifier too, but I would rather treat that as added value useful for those who can't at the moment afford a high quality stand-alone preamp. Hegel will show its true value when combined with high quality, active preamplifier especially when connected via RCA cable.

Interestingly the streamer works really well, so well that there is no need to play music from a computer via USB. Yes, there are better performing streamers on the market but this one offers a really nice, rich sound. Knowing that this is in fact just a bonus to the device we bought we should be simply grateful and enjoy its performance.

When we treat it as a D/A Converter what we get is a high-end product. One could combine it with a high quality stand-alone streamer and that should result in a very, very good performance. But I would encourage you to forget about market's trends for a moment and combine Hegel with a high quality CD Transport. I'm pretty sure that many of you will start to appreciate CD (maybe again). RED Fingerprint

Hegel calls HD30 a D/A Converter – writing on the rear panel reads: „HD30 High End Digital to Analog Converter”. But as we already know D/A conversion is just one of its functionalities – it is also a streamer and it offers a volume control. So what we actually get is a streamer with digital inputs and digital preamplifier, all in one box.

Front and rear panels

If you look at HD30 you will surely notice similarity with Hegel's amplifiers, especially with H70. The thick, slightly curved front panel looks really good. It sports a large blue LED display. It presents information on active input and volume level. The later uses a scale from ‘0’ to ‘101’, with the latter indicating that the volume control is actually by-passed. Unfortunately no information is displayed regarding input signal – no word depth, sampling frequency or file format. Nothing even indicates whether DAC is synchronized with the source. When working with DLNA server Hegel indicates that with a small dot on a display.

There are two knobs on both sides of the device – one operates input selector the other volume control. The whole chassis is made of aluminum – alu plates are bolted together. HD30 sports three feet made of aluminum and rubber – two in the front and one in the back. The main on/off switch sits on the rear panel next to IEC socket which might be a suggestion to leave the device on at all times. When it comes to digital devices it is important to provide precise oscillator with optimum working conditions – these are insured when device remains on all the time.

HD30 offers a lot of digital inputs: 3 optical Toslinks, one RCA and one BNC SPDIFs and one AES/EBU. Additionally there is also an USB input placed right next to Ethernet port. One will find a small switch next to USB port that actually changes its operating mode – it can accept PCM signal up to 24/96 and than it requires no drivers, or it can also accept files of even higher resolution and than driver is required.

There are both types of analogue outputs: RCA and XLR, both with solid, gold-plated sockets.

Inside

The whole electronic circuit spreads on two PCBs – the bigger one hold D/A Converter section, the smaller one: streamer and USB input. Each of them includes also a completed power supply section. There are separate toroidal power transformers for streamer and for DAC. The electronic circuits are shielded from power transformers. IEC power inlet is integrated with a RF filter. Taking the internal design into consideration one can easily tell that this are: a streamer and a DAC put together in one chassis.

The streamer section is based on Microchip Technology module that sports a separate (from controlling section) power line. The more advance DAC section uses even three power lines. All inputs sport matching transformers. Input section uses the AK4118 chip (a digital receiver for 24/192 signal), the AK4137 (VERITA's sampling frequency asynchronous converter that coverts any input signal into 32 bit / 768 kHz one) and the AK4127 (asynchronous converter that coverts any input signal into 24 bit / 192 kHz one). VERITA is a very interesting product as apart from its up-sampling feature it is also able to convert PCM signal to DSD and the other way around. I'm curious which role does it play here.

The actual DAC chip is AK4490EQ – actually there are two of them, one per channel. It is another very interesting new chip capable of accepting PCM signal up to 32-bit and 768 kHz but also a 11,2 MHz DSD (Direct Stream Digital). Japanese manufacturer called its architecture: Velvet Sound, and it utilizes 5 selectable digital filters.

Remote

Hegel always offered nice, solid remote controls and we get one also this time. Small buttons of RC8 give user access to streamer's, DAC's and preamplifier's functions. With a compatible computer one might use this remote also to control a software music player.

Specifications (according to the manufacturer)

Accepted PCM signal: up to 24bits, 192kHz
Digital inputs: AES/EBU, BNC, RC, 3 x TOSLink, USB, Network
Linear outputs: RCA + XLR
Frequency range: 0Hz-50kHz
Distortion: <0,0005%
Dimensions (H x W x D): 100 x 430 x 310mm
Weight: 10kg