November 2017

Sennheiser HDV 820 DAC / Headphone Amplifier
Analytical, schmanalytical. Who says your HD800 can't be fun?
Review By Dave Hanson

  Confession time. I usually don't expect much from headphone manufacturers when it comes to building their own amplifiers. I've never particularly liked any of the amplification offerings from companies like Beyerdynamic, HIFIMAN or Fostex. At best, I guess I was somewhat indifferent to the original Sennheiser HDVD 800. I felt it sounded good enough, but I also didn't feel like the sound-per-dollar value or absolute performance was particularly worthy of recommendation over similarly priced amplifiers, in most cases.

So I approached Sennheiser's new flagship DAC/amp, the HDV 820 ($2399), with a bit of skepticism. On one hand, you have that fairly checkered history of amps from headphone manufacturers. On the other, you have a pretty convincing piece of evidence for the other side of the argument: the last DAC/amp Sennheiser designed was attached to the Sennheiser HE-1 ($55,000), claimed by some to be the world's best sounding headphone system.

To my delight, it turns out the new Sennheiser HDV 820 is the genuine article. Not just an adequate performer or a synergy master specifically for the HD800 and HD800S, but a truly exceptional piece of equipment. So what makes this one succeed where others have failed? Let's take a look.

A Jack of All... Or Most Trades
The first thing the HDV 820 has going for it is versatility. Lots and lots of versatility. It has all of the standard digital inputs: USB, optical and coaxial; plus balanced and unbalanced analog inputs. And it has more than its fair share of outputs: 6.3mm unbalanced, 4-pin balanced, (two) 4.4mm balanced Pentaconn connectors, and 3-pin balanced outs on the rear side allowing the HDV 820 to be used as a preamp for active monitors.

The second thing it has is power, and lots of it. Per Sennheiser's Axel Grell, it puts out a very clean 2.76 Watts of power at 32 Ohms, 2.5 Watts at 50 Ohms and 960mW at 300 Ohms. While 2.5W at 50 Ohms may not sound particularly jaw-dropping to the power-hungry planar crowd, let me assure you, this amp has more than enough current on tap to get the job done. It drove the ever-demanding Abyss AB-1266 (86dB sensitivity) fairly well, and had absolutely no problems driving the slightly-less-demanding ZMF Ori and HIFIMAN HE500.

On the opposite end of the sensitivity spectrum, HDV 820 was a bit on the strong side for ultra-sensitive in-ears and I heard a bit of hum when I tried it with the Campfire Vega (reviewed here). Unfortunately, I was not able to test IEMs with a balanced connector, so I can't comment on the noise drop with the benefit of common mode noise cancellation. My full-sized sensitive headphones performed well however, including my Grados and my modded Denon D2000, which is quite sensitive at 106dB/mW and 25 Ohm impedance. The background was nice and black on the hyper-sensitive Denon, and the HDV 820 was able to milk out one of the best performances I've heard from it in a while.

For the digital section, Sennheiser has chosen to employ the ESS Sabre ES9018 chip. Sabre DACs have taken a fair share of flack – and much of it is well deserved – but keep in mind, the sound of a DAC is really about 2% chip and 98% implementation. While the ES9018 may not be the world's most popular chip among personal audio enthusiasts, I believe most of that is really due to its frequent implementation in poorly designed DACs. It's actually implemented pretty well here. There was none of the trademark "Sabre Glare" that you often find in many ES9018-based DACs.

That being said, I like the amplifier quite a bit more than I like the DAC for entirely different reasons, which I'll get into in a minute. The DAC, isn't terrible by any means (and it actually reminded me of a DAC that I like quite a bit), it's just that the amplifier outclasses it and scales up significantly with a better DAC. So, on that note, I'm going to examine them both separately, so you'll know what to expect and can make an informed buying decision. We'll start by taking a look at the amplifier section.

Okay Guys, Where Did You Hide The Tubes?
The HDV 820's amplifier is really one sweet-sounding piece of kit. The tone runs a little on the warm side of neutral, which really brings out the best from the somewhat dry-ish and by-the-book HD800.

In some ways the HDV 820's tonality reminds me a little of the slightly lush, but hyper-detailed presentation of the now discontinued Cavalli Liquid Gold, which is one of my all-time favorite pairings with the HD800. It's not an exact match, but bears some tonal similarity to the legendary LAu in its ability to even out the HD800 and make it sound stunningly realistic. It's not quite as expansive and maybe a pinch behind in transparency, but for $1600 less, it's close and it certainly isn't lacking in either of those aspects.

Treble is held under a firm grip of control and is buttery smooth on the occasionally unforgiving HD800. In over a month with the amplifier, I can't recall cringing at a sibilant treble spike. It's not going to magically make the HD800 a top-choice for k-pop all of a sudden, but it certainly expands the HD800's range of enjoyable music quite considerably. There is ample air up top, which gives the music a free and easy feel, though the amplifier is perhaps not as supremely airy and open sounding as some others like the Rogue Audio RH-5 (reviewed here), which is elite in that regard.

The midrange is where this amplifier truly shines, in my opinion, delivering superb musicality that is usually only reserved for tube amps. I found the HDV 820 really excelled with rock music, delivering gobs of soul that had me feeling very connected to the music. The upper midrange is a little warmed and mellowed out – a trait that I often describe as "speaker-like", while the lower mids feel extra full and robust. It's a warm and sweet sound, and when you've got a good album rolling, this is a very hard amp to walk away from. I was absolutely glued to my chair after I popped on Steely Dan's seminal classic "Aja", and soon found myself re-prioritizing my evening just so I could give it a second spin.

The bass is also warm, with solid (but not elite) rumble and impact. It is certainly enough to be satisfying and I never really found myself needing more. The low end also has a bit of that aforementioned tubeyness to it. Low frequency notes come off as slightly more rounded and natural than punchy and abrupt – which is not to say it is loose – there is actually a ton of information down there. As a bass player myself, this type of sound comes across to me as more "live" than "studio-like". I don't necessarily feel one way is better than the other, they are just different.

To elaborate a little further, bass in a live setting reverberates off of just about every surface in a given room, which often adds a layer of harmonic richness to the sound that is not always present in solid state amplifiers. Tubes usually do a better job of duplicating those harmonic overtones, which to my ears, generally makes them sound a tiny bit more transparent. I feel like the "tubeyness" of the HDV 820 also captures a lot of that natural low-end detail too. Bass was far from the "one-note" variety, and I even picked up a few nuances I'd never noticed before, even in really good gear.

The inner detail of the amplifier is quite strong, and it really showed its stuff when paired with the ultra-detailed Chord Hugo 2 (reviewed here). But what really impressed me was the level of ambient micro detail. Tiny decay trails off the end of instruments revealed the size and shape of the recording space with a stunning level of precision. Listening to Adele's "Hello" was a revelation. The performance was super intimate, and I felt like I was right there in the room for the recording. Each additional vocal harmony that was introduced was well-separated, highly-detailed and impressively appreciable as an individual element.

Now we've come to perhaps my favorite part of the HDV 820, the soundstage and imaging. You had to imagine that an amplifier that is designed to be paired with the legendary HD800 would do this well, and the HDV 820 really knocks it out of the park.

To me, the most impressive part of the soundscape isn't the size, it is the immersion it offers. The stage isn't as massive as the recently reviewed Rogue Audio RH-5 or a pair of Questyle CMA800R's running in dual mono. Those amplifiers offer truly elite width. However, what the HDV 820 does in terms of enveloping you in the sound is, in my opinion, every bit as impressive. Listening to the HDV makes it feel like you are inside the music, creating a deeply emotional listening experience.

How does it do this? The answer lies in the excellent depth layering – without a doubt, some of the best I've heard from a pure solid state. Listening to Bohemian Rhapsody in DSD on the HDV 820 via the Chord Hugo 2 was stunning. I was literally sitting there with my jaw hanging wide open as the multi-layered vocals unfolded at pinpoint spots front-to-back on the stage. Not surprising that this was designed by the same folks who designed the HE-1 – even though it is nowhere near as expansive or multi-layered as the HE-1, it brings a little tiny taste of it's field depth magic at a price that's much more attainable for the rest of us.

As amplifiers go, I would take no issue with recommending the HDV 820 as an amplifier alone at its full retail price of $2395. To my ears it is an outstanding piece and absolutely worthy of its substantial price tag. But this isn't just an amplifier, there is also a DAC onboard. So how does it perform?

Let's Play Name That DAC!
While the DAC is quite good, it a bit more of a mixed bag than the outstanding amplifier section. Switching over from the unbalanced input, there was a substantial jump in volume with the amplifier now running in balanced mode off of the internal DAC. It took a little bit of tweaking to ensure test conditions were fair and setup properly, but once everything was in order, comparison tests with other DACs were fairly straightforward.

Comparing first to my reference Hugo 2, I found that the HDV 820's DAC was not as detailed or transparent as the Chord unit, but was still actually quite detailed. Instruments had fairly natural sounding timbre to them, but the Hugo 2 clearly performed better with more tonal nuance in the mids and better control in the high frequencies. The HDV 820's internal DAC occasionally had a little extra sharpness on a sibilant "S" here or there. With the Hugo 2, the amp was sufficiently warm that I could really crank it up and not worry about it.

Without direct comparison to a better source, you probably wouldn't notice the difference. Still, I found it harder to sit for long sessions with the onboard DAC, whereas it was much more difficult to get up and walk away with the Hugo 2 plugged into the HDV 820's amplifier section. However, the Hugo 2 costs as much as the HDV 820 itself, so perhaps comparing it directly to the DAC alone isn't entirely fair. With that in mind, I also compared it to the DAC section of a respectable DAP (the Acoustic Research AR-M2, $1199) and two mid-priced DACs: the Audio-GD DAC-19 ($899) and the Chord Mojo ($529).

Compared to the Acoustic Research AR-M2, the HDV 820's DAC started looking much better. I noticed more presence and assertiveness, stage depth, color, warmth and musicality from the HDV 820's DAC while using both Amarra 4 Luxe and Roon off of my MacBook Pro. Comparing a 24-bit/96kHz version of Buena Vista Social Club's self-titled album, music out of the AR-M2's relatively good Burr-Brown DAC sounded a little more like a facsimile than the real thing. It came off as somewhat plasticky in relation to the analog warmth of the HDV 820.

Going up against with the Audio-GD DAC-19, proved to be an interesting matchup. The DAC-19 remains my standard for a good sounding, sub $1000 headphone DAC, using an excellent implementation of the Burr-Brown PCM1704UK R2R chip. It runs a little on the warm and gooey side, but sounds very analog, and is quite detailed. Head-to-head, the HDV 820's digital section fell a little short, as the Audio-GD offered a better sense of depth and analog resolution to the individual sounds. The DAC-19 also offered a bit better impact, dynamic thrust and a better sense of connectedness with the natural PRAT (pace, rhythm and timing) of the song. Switching back and forth, there seemed to be a very slight sluggish haze on the HDV 820's DAC, but overall it wasn't terribly far behind. All of the differences were small.

Last but not least, I compared the HDV 820 directly against the Chord Mojo. The Mojo is a sensational and immensely popular mid-priced DAC, and represents one of the very best values in all of high-end audio. Matched up against the HDV 820, I had a very difficult time hearing any discernable differences between the DACs, at all. In fact, I couldn't find one single consistent difference to call out in the review. To me, they sound nearly identical. Overall, that's not a bad place to be for the HDV 820, as I feel like the Mojo is an excellent piece of gear and I recommend it frequently. It scales well, and I've used it with amps that are as good or better than the HDV 820 on many occasions.

So while the DAC section may not be as much of a standout as the amplifier, it is still more than respectable, comparing favorably to one of the most popular DACs on the market today. Just understand that what you're getting is more like a $2000+ amplifier and a $500ish DAC than an even split, if that's what you were expecting. It will get the job done very well if it is your only piece, but there is substantial room to scale up by adding a better digital component like the Hugo 2 or the Schiit Yggdrasil. It also means the HDV 820 is a piece that can grow with your setup over time.

Final Thoughts
So where does the HDV 820 fit within the headphone amplifier landscape? I would say it slots in pretty comfortably for a warm all-rounder at its price point. Compared to other recently reviewed pieces, I would say it isn't as thunderously dynamic or incisive as the powerhouse Wells Milo (reviewed here); and it isn't quite as airy, open and expansive as the recently reviewed Rogue RH-5. But I would call it the most lush and musical option of the three. In many ways the three are equally good, albeit markedly different sounding amplifiers.

Given that the HDV 820 also includes preamp outs (the RH-5 does as well) and an onboard DAC, it certainly has a lot going for it from a value perspective. One should note that it is a little bit colored on the warm side when considering it as a total reference piece, and professional users may want to lean toward the slightly more neutral Rogue RH-5 as a benchmark for their mixing decisions. However, audiophiles looking to expand the musical range of their HD800 will definitely want to give this one a look.

In my opinion, the balance offered by the added warmth here ensures that the HD800 will likely be the only headphone you'll ever need. That being said, the HDV 820 is versatile enough to offer top-flight synergy with many other headphones too. Particularly offerings from MrSpeakers, which will garner added fullness from the Sennheiser's amp section and take full advantage of its excellent depth layering; and Fostex/Denon biocellulose variants, which will benefit from the HDV 820's warm lower midrange presentation and well-behaved treble.

At the end of the day, I think Sennheiser has introduced a real gem here. It's a fun sounding piece of equipment and I feel like this is a piece I'll be recommending frequently in the near future. If you're looking for a slightly warm and lush do-it-all piece that can add some musicality while keeping pace with your most resolving headphones, definitely give this one an audition.

Specifications
Type: Headphone amplifier with DAC
Output Power: 2.76 W/ch (32 Ohm), 960mW (300 Ohm)
THD+N: <0.001%
Frequency Response: <10Hz to >100kHz
Crosstalk: -93dB @1kHz
Digital Inputs: USB, coaxial S/PDIF, optical TosLink
Analog Inputs: Unbalanced RCA, dual 3-pin balanced
Analog Outputs: 6.35mm unbalanced, 4-pin XLR balanced, two 4.4mm Pentaconn balanced, dual 3-pin balanced preamp outputs
Supported File Formats: PCM rates up to 32-bit/384kHz; DSD64, DSD128, DSD256
Size: 224mm x 44mm x 306mm
Weight: 4.96 lbs.
Price: $2399

Company Information
Sennheiser Electronic GmbH & Co. KG
Am Labor 1
30900 Wedemark
Deutschland

Voice: (877) 736-6434
Website: www.Sennheiser.com