Hegel HD25 DAC
The HD25 is the natural digital hub in any audio system. It has four digital inputs and two analog outputs. The digital inputs can be used to connect a tablet, computer, streamer, Sonos, cable TV or music center to your existing audio system.
The HD25 is the natural digital hub in any audio system. It has four digital inputs and two analog outputs. The digital inputs can be used to connect a tablet, computer, streamer, Sonos, cable TV or music center to your existing audio system. And with greatly improved sound quality. The HD25 has a built in pre amplifier and a remote control which allow easy integration with active loudspeaker systems or headphone amplifiers. Should you lose your remote control, you may switch inputs by simply tapping on the front panel. If you plan to use it together with a computer as a source, the HD25 is especially clever. Out of the box it is very simple Plug & Play. Connect the USB cable and immediately enjoy high quality sound.
On the technical side, the HD25 borrows a lot of technology from the Hegel Reference products. One of these is the use of silicon germanium transistors. These components add extremely low levels of noise, resulting in unsurpassed levels of resolution and a more natural and pleasant sound. You can also switch between two different digital filters to adjust the sound to your taste. All inputs are impedance matched to minimize distortion due to the quality of the digital cables. In addition, all inputs are galvanically isolated.
OPTIONAL: If you want to explore super high resolution material (24/192) on USB, the HD25 supports this too. You simply flip a switch on the rear panel and install our high resolution driver. All other inputs supports this resolution without any extra drivers.
DAC resolution: 32 bit/192 kHz multilevel sigma-delta DAC
0dBFS signal output: 2,5V RMS
Digital inputs: 1 x USB soundcard, 2 x coaxial and 1 x optical S/PDIF
Line outputs: 1 pair of RCA unbalanced, 1 pair of XLR balanced
Frequency response: 0 Hz to 50 KHz
Phase response: Linear Phase Analogue filter
Noise floor: Typically -145 dB
Distortion: Typical 0,0006%
Power supply: Built-in torodial transformer, 30,000 uF capacitors
Output impedance: 22 ohms unbalanced and 44 ohm balanced
Dimensions/weight: 6cm x 21cm x 26 cm (HxWxD), 3,5 Kg
Dimensions/weight US: 2.35″ x 8.3″ x 10.24″ (HxBxD), weight 7 lbs)
Hegel Music Systems HD25 Digital-to-Analog Converter
- Jeff Fritz | Soundstage UltraAudio
- There isn’t a more noteworthy trend in high-end audio today than that of companies smashing the price/performance ratios of yesterday — in both directions. You don’t have to look far to see abysmal $200,000/pair loudspeakers, and you can find a gem for very little money around almost any corner. Hegel Music Systems is firmly about the latter.
Hegel, of Norway, has made a steady push into the heart of high-end audio with a stream of products that has helped expand audiophiles’ ideas about what level of performance they can and should expect for reasonable prices. I can think of no finer example of that than their H300 integrated amplifier-DAC ($5500 USD), which Hans Wetzel reviewed for GoodSound! in late 2012, and which won a SoundStage! Network Product of the Year award for Exceptional Value. Hot on the heels of the H300 came the announcement of the HD25 digital-to-analog converter ($2500), Hegel’s new top-of-the-line digital offering. Yes, you read that right: The best DAC the company makes costs only $2500. Isn’t that, alone, refreshing?
The HD25 has four digital inputs: two coax S/PDIF on RCA, one USB, and one optical S/PDIF on TosLink. It has two sets of analog stereo outputs: RCA and XLR. Hegel describes the HD25’s DAC chip as a “32-bit/192kHz multilevel sigma-delta DAC”; with a few adjustments, all inputs support all resolutions up to 24-bit/192kHz. The HD25 is shipped with the USB input set to 24/96 so that, out of the box, and without you having to install any drivers on your computer, it will be plug’n’play in any installation. Yet it takes just minimal effort to adjust it for higher resolutions: To have the HD25’s USB input accept 24/192, you install a driver on a Windows PC, or simply select the HD25 as the output device in a Mac’s Audio MIDI settings, and flip a tiny switch on the Hegel’s rear panel from A to B.
Unlike DACs with wall-wart power supplies, the HD25 has a substantial internal supply that comprises a generously sized toroidal transformer and 30,000µF of filter capacitance. Hegel states that silicon-germanium transistors were chosen for their low noise. Providing a choice of digital filters is all the rage in high-end DACs these days, and Hegel has followed suit: the HD25 has two. The default filter is F.1, which Hegel refers to as “normal”; F.2 is “a minimum preringing and low latency filter.” I compared the filters early on and found that F.2 sounded slightly more natural, so that’s what I used for almost all of my listening. The HD25 doesn’t operate asynchronously, as is de rigueur for DACs today, but in adaptive mode, which the Hegel engineers think sounds better. All inputs are claimed to be impedance matched to minimize any distortion created by the digital cables used, and all inputs are galvanically isolated for lower noise. The HD25’s built-in, 100-step digital volume control means that it doesn’t need a preamplifier — it can be directly connected to powered speakers or a power amplifier.
One supercool feature of the HD25 is its faceplate: There’s no control for selecting the input. But the HD25 has a little secret: Tap the front panel twice, and the input changes. Keep tapping to scroll through all four inputs. This may sound like a mere gimmick, but I found it useful. I never had to bend down to read the labels on a row of tiny input buttons — instead, I could just tap the front panel twice as I walked by, as quickly as double-clicking a computer mouse. Neat trick.
The HD25 is small: it measures 8.3″W x 2.35″H x 10.24″D and weighs only 7 pounds. The faceplate is bead-blasted aluminum, the casework is painted steel — solid enough, but far from extravagant construction; I’ve seen better and worse at the price. My strongest criticism of the HD25 concerns its tiny plastic remote control, which looks like something that would come out of a 25¢ gumball machine. It’s the cheapest-looking and -feeling remote I’ve ever seen with a high-end product. On the plus side, in addition to operating the HD25’s volume control, input selection, and display on/off, the remote will also operate most computer music-player software — my iTunes-Amarra setup worked flawlessly with the HD25’s little remote. The remote will also control various functions on Hegel amplifiers and CD players — it may look and feel cheap, but it’s very functional.
The HD25 is designed to be left powered up at all times; the main power switch is a rocker on the rear panel, next to the 15A IEC power-cord inlet. I left the review sample turned on for almost the entire review period, and it never hiccupped in any way.
As editor, I sometimes get on our reviewers for describing sound in terms that can mean very different things to different readers. A case in point is musical. In the context of most audio reviews, musical means that the reviewer enjoyed listening to and was drawn into the music, and found nothing particularly objectionable about the sound. That’s nice, but it doesn’t tell us much. After all, I might find some aspects of sound reproduction more important than others to my enjoyment of music, and those aspects might differ from what’s most important to you — which would mean that you and I would have different definitions of what is musical. What sounds “right” to you might annoy the heck out of me, and vice versa.
But when I listened to the HD25, musical was the word that came to mind. I thought about what I meant by it in this context, and here’s what I came up with. First, the HD25 was smooth throughout the entire audioband, regardless of what I was listening to. By smooth I don’t mean that it glossed over details, but that it rendered an even tonal balance, with no peakiness to be heard anywhere. The HD25 didn’t sound bright or dark, and didn’t produce any objectionable edge or harshness in the mids or highs. All sounds popped out at the right spots, but no area of the audioband was spotlit or recessed, as happens with some gear.
For instance, I was impressed as I listened to James Horner conducting the London Symphony Orchestra in his score for the film Braveheart 16-bit/44.1kHz ALAC, Decca): I found myself focused on the performance as a whole, and not individual elements within the orchestra. The sound was very neutral and balanced, tonally, which kept my attention firmly on the music. I wasn’t aware of sonic details in a way that screamed hyper-resolution, but I could easily hear deep into the music without having to make a concentrated effort to do so. In this context, musical meant balanced and subtle — it meant that, in encouraging me to explore my music collection, the HD25 was consistently bringing me great enjoyment.
Most striking was how the HD25 let the soundstage develop in my room — not a tonal but a spatial characteristic. Because the sound was not hyper-focused, I didn’t find myself zeroing in on tiny spatial nuances that I could point a finger at; instead, the HD25 created a realistically sized soundstage that was expansive in both width and depth. Images were always of the appropriate size. In this regard, I would also describe the Hegel’s sound as free-flowing — music poured from my system with an ease and a suppleness that were, at all times, in service to the music. It was as if the DAC were relaxed, not sweating the job at hand, and that sense of ease was passed along to me. Whether listening to James Taylor or Taylor Swift, I found myself having fun with a wide variety of music. I attribute this to the Hegel’s balanced nature and, again, the ease with which the HD25 presented music.
Still, the fact that the HD25 sounded great with so many types of music doesn’t tell the whole story. I pushed deeper into its sound with some high-resolution recordings, to see if I could spot any flaws that might otherwise go unnoticed. The Allegro of Mozart’s Violin Concerto No.4 in D Major, K.218, performed by Marianne Thorsen, with Oyvind Gimse conducting the Trondheim Soloists, on the 2L-TWBAS 2012 Sampler (24/176.4 FLAC, 2L/SoundStageRecordings.com), was beautiful. It wasn’t presented in a hyper-realistic way — I didn’t feel as if my ear was pressed against the violin’s strings. But it was complete, with enough detail and precision to be instantly recognizable as a hi-rez recording. As I continued to listen to the Sampler, my opinions remained the same: the tonal balance was neutral, with just enough detail, and the soundstage was huge when that was called for. All of this combined to make long listening sessions the order of the day. I simply wanted to listen longer, and found myself less focused on sound and more on music. In terms of evaluating the HD25 in terms of enjoyment, it was a resounding success. But how would the HD25 fare when pitted against a DAC with a set of strengths that would seem to run counter to the Hegel’s?
dCS Debussy vs. Hegel HD25
A ridiculous comparison? In terms of build quality, yes. The dCS Debussy is built to a very high-end standard: thick aluminum panels contoured and joined to exacting tolerances, with chassis-mounted connectors that scream quality. The remote is substantial; it’s heavy and sculpted, with a nice rubberized feel. The 21-pound Debussy feels like a Rolex watch, and costs as much: $11,500. The Hegel HD25 is utilitarian. Though its thick aluminum front panel is understated and of high quality, its case is sheet metal, and the RCA connectors on the rear panel are mounted not on the chassis but on the circuit board — they didn’t feel nearly as solid as the dCS’s jacks when I connected or disconnected cables. The HD25 didn’t feel exactly flimsy, but it’s a far cry from the jewel-like Debussy.
But when I’d level-matched the two units and sat down to listen, the comparison was not ridiculous at all. The Debussy, as always, was clean as a whistle: highly resolving and detailed, but without spotlighting any particular frequency. When the backing vocals in “O Come, O Come, Emmanuel,” from Enya’s And Winter Came (16/44.1 AIFF, Reprise), enter at about a minute in, the soundstage broadened and deepened impressively, allowing the Debussy to stretch its legs and show what it was capable of. The dCS played it straight — it didn’t exaggerate anything, nor did it hold back in reproducing the tiniest details and ambient cues in really good recordings. With pop and country selections it could sound propulsive and flat, portraying precisely what was on the recording; with better recordings, there was a healthy dose of soundstage depth and air around performers that gave it a very “live” feel. dCS has produced, in this “entry-level” model, a DAC that can hang in the very best systems. I’ve used it as my reference for just over a year and a half, and have never felt it to be a limiting factor in my system.
The Hegel HD25 countered with a sound that was slightly softer but equally enjoyable to listen to. With some recordings it actually sounded bigger and more expansive than the dCS, which surprised me. The Enya track, for example, sounded wider when the chorus entered. As a rule, the HD25 sounded bolder and more tonally dense than the dCS. On the other hand, the Debussy seemed to retrieve a touch more fine detail at the frequency extremes, which seemed to give it an edge when I listened at lower volume levels. However, I was drawn back to the Hegel’s sound again and again, particularly when I wanted to just relax into that massive soundstage and get lost in the music. I’m confident that the dCS is the more transparent device, and therefore would be preferred for use as a tool in dissecting the precise placement of performers within the soundstage or analyzing/isolating the sound of other components. With some music, such as “Cry Like a Baby,” from Australian country crooner Casey Chambers’ The Captain (16/44.1 AIFF, Asylum), the results were a wash — although such selections sounded different through the two DACs, I equally enjoyed both sounds.
There’s no question that the dCS Debussy is among the finest DACs released in the past few years. Although a far stretch from dCS’s flagship Vivaldi stack, released in mid-2012 and the company’s most ambitious effort, with a six-figure price, $11,500 is still a lot of money for a DAC. What’s amazing is that the Hegel HD25 was far closer in sound quality to the dCS than its $2500 price gives it any right to be. Does this mean that the most recently produced DACs have improved that much, or that Hegel has figured out a way to get really great sound for surprisingly little money? I think both are true. Bottom line: If you buy an HD25, you won’t be left wishing for a DAC like the Debussy. I could happily live with the HD25 and not look back.
Unless you need your audio components to be high-end jewelry, Hegel Music Systems’ HD25 digital-to-analog converter is an easy recommendation. I can’t think of anyone who wouldn’t like its sound. The HD25 throws a huge soundstage, and is as tonally balanced as the best high-end gear. Its sound will encourage long listening sessions, and I don’t think anyone who hears it will find it obviously lacking in detail or nuance. Although you can buy a higher-resolution device for more money, I’m not sure you’ll find one that you’ll enjoy as much, regardless of price. The reason? That elusive quality of musicality. That makes the Hegel HD25 a Select Component, and a surefire way to elevate your sound system for what is, by today’s high-end standards, relatively little money.
. . . Jeff Fritz