Sennheiser HDV-820 USB DAC & Headphone Amp Review

[Dana reed]

If Sennheiser meant to make 43Ohm on it's flagship beyerdynamic tops it on it's €999 amp with 120 Ohm: https://www.beyerdynamic.de/a-2.html

Seriously now, I do think they know what they do!!!!

The A20 has fixed 100 Ohm output impedance, but it appears the more expensive A2 has a switchable impedance.
Screenshot from manual below:

 

[solderdude]

The HD700 and HD660S drivers are not the same.

Looks like HDVA600, HDVD800 and HDVD820 all share the same TPA6120 output stage.

 

[canonbli]

As an owner of HDV820, I use it only to drive my HD800S, and I like the sound of it. Despite of the bad results of your review, I tried lots of DAC/AMPS at the same price, and this is what I took home with.

 

[YSC]

sad that a reputable reference class headphone maker and especially GERMAN maker did screw up their ref dac amp this much

 

[Clintosity]

Hmm surprised this measures unwell, i went to the store to try some gear with my HD800S's and this one was by far the best with them. Obviously i didn't buy it due to the price but yeah i'd be able to blind pick it easily because there was such a difference.

 

[Veri]

i'd be able to blind pick it easily because there was such a difference.

So you say

 

[Clintosity]

So you say

I really do think so, i'm not one to claim i can hear the difference between Spotify or 24bit flac and i also don't think i could do it between half of the stuff there but something on that 820 really wow'd me.
I was there for an hour listening to stuff from entry level all the way up to the Moon 430HA which was more than double the price. Went back and forth multiple times. The 820 was the standout and every time i went back to it i was like ahhh.
If you gave me the option of the Moon Audio or the 820 for the same price i'd take the 820.

 

[Veri]

I really do think so, i'm not one to claim i can hear the difference between Spotify or 24bit flac and i also don't think i could do it between half of the stuff there but something on that 820 really wow'd me.
I was there for an hour listening to stuff from entry level all the way up to the Moon 430HA which was more than double the price. Went back and forth multiple times. The 820 was the standout and every time i went back to it i was like ahhh.
If you gave me the option of the Moon Audio or the 820 for the same price i'd take the 820.

I also auditioned the HD820 with the HDV820 (4-pin XLR output), there was plenty of power which is good, but otherwise didn't notice anything special or different about this amp myself. No idea how the Moon Audio performs.

 

[Clintosity]

I also auditioned the HD820 with the HDV820 (4-pin XLR output), there was plenty of power which is good, but otherwise didn't notice anything special or different about this amp myself. No idea how the Moon Audio performs.

Only listened to the amps with my 800S, unfortunately there was no auditioning their headphones due to covid. Might be different i guess if i had tried more pairs of headphones on the different amps. How'd you like the HD820's? They get a pretty bad rap but would of loved to try them.

 

[Veri]

Only listened to the amps with my 800S, unfortunately there was no auditioning their headphones due to covid. Might be different i guess if i had tried more pairs of headphones on the different amps. How'd you like the HD820's? They get a pretty bad rap but would of loved to try them.

The comfort & bass is quite nice, but there is a distinct weird tonality in the mids that makes for a really weird response. "wonky" is an accurate description I'm afraid.. especially if you're used to neutral sounding headphones which these are just.. not.

 

[alexrus]

Has HDVD800 and SMSL SH-9 (THX AAA). Prefer HDVD800 balanced with HD800S - more natural sound for my ears

 

[Pelikanyo]

I purchased this along with the HD800s, and both digital and balanced analog signals sound superb.
Scientifically, a second unit would be tested for comparison

 

[trl]

What differences would you expect to see? From Amir's tests I understand that the DAC inside measures very well, while the internal headamp is not designed for pure performance with its 45 Ohms output impedance, a rather high background noise and about average output power.

Here's how the HDVD sibling measures: https://reference-audio-analyzer.pro/en/report/dac/sennheiser-hdvd-800.php#gsc.tab=0, you can see a much worse THD than the HDV.

 

[Pelikanyo]

Can anyone tell me...are the XLR outputs disconnected when headphones are connected to the front panel?
Thanks

 

[JamesRF]

As an owner of HDV820, I use it only to drive my HD800S, and I like the sound of it. Despite of the bad results of your review, I tried lots of DAC/AMPS at the same price, and this is what I took home with.

I agree this is a fine amp with the HD800S. I think this combination is one of the two or three best headphone systems available at any price.

 

[trl]

Am I missing something, please? Can we please rewind to the first page and look again on the graphs? It looks to me that the inside DAC is quite good, while the headamp is subpair.

 

[MalinYamato]

This is a review and detailed measurements of Sennheiser HDV-820 DAC and Balanced Headphone Amplifier. It is on kind loan from a member. The HDV-820 costs US $2,400 with Prime shipping from Amazon. Settle down! I know you can't afford it but maybe it is good.

While the enclosure itself is not that unique, Sennheiser nails the feel and look at the controls:

View attachment 42566​

Usability is not quite there though. I literally had my thumb pinched between the volume control and input selector. In reverse, trying to change the inputs, your fingers may hit the volume control.

Other than that, the volume control, selector and especially the power button with its white LED ring are quite nice. The light pipes for the input indicators bleeds to adjacent labels which is unfortunate.

As you see, you have every type of headphone output and then some. Back panel shows a lot of inputs and outputs as well:

View attachment 42567​

Nice to see analog inputs on a DAC+Amp combo.

Lacking is AES digital input in this price range.

There are no gain controls. Just turn up the volume and it will keep getting louder. This likely will hurt its signal to noise ratio.

DAC Audio Measurements
As usual, we start with our dashboard with XLR Output:
View attachment 42568

XLR output seems to be tied to headphone out as it could go as high as 11 volts output! I dialed it down to 4 volt for above measurement. Distortion+noise is in the competent range:
View attachment 42569

Signal to noise ratio is not as good as it should be for this price range:
View attachment 42570

Jitter is very good:
View attachment 42571

Multitone test shows low intermodulation distortion:
View attachment 42572

But when we measure that relative to level, we see the clear signature of ESS DAC chip:
View attachment 42573

We have the classic "ESS IMD Hump" and higher noise in general.

Digital In Headphone Amp Measurement
The headphone amplifier works with analog input and output. But I thought I measure it in combo with the DAC first:
View attachment 42574

We have good bit of power but disappointing distortion and noise level. Above is with the volume turned down. The higher the volume, the higher the noise level. They should have implemented a gain setting.

Headphone Amplifier Measurements
For these tests I fed the HD-820 with XLR Input (in the back -- don't confuse this with XLR Headphone out). I started with 1/4 Headphone output:

View attachment 42575

This is not good. There are a lot of amps that do better:
View attachment 42576

Signal to noise ratio is nothing to write home about:
View attachment 42577

View attachment 42578

Expect to hear some hiss with sensitive IEMs and headphones.

Frequency response is dead flat and hence excellent:
View attachment 42579

But this doesn't mean you get flat response from your headphones because of this:
View attachment 42580

45 Ohm impedance means that unless your headphone has a flat response (e.g. planar magnetics), its frequency response is going to change. This may make it sound better or worse. It also means lots of power will be wasted into low impedance headphones. We will see this effect shortly.

Here is power vs distortion into 300 ohm load:
View attachment 42581

Wow. The gap in noise and distortion is quite massive relative to our state-of-the-art headphone amps we can get today for as little as US $99. We do have lots of power though so dynamic range won't be an issue.

Issue you will have with low impedance loads like 33 ohm:
View attachment 42582

This is just bad for a desktop headphone amplifier.

Comparing 1/4 "unbalanced" headphone output to "balanced" XLR Output we get:
View attachment 42583

I was surprised how much cleaner XLR output was. But then it got distortion even more than 1/4 headphone out. You do get four times more power with XLR output which is always good to have.

Sweeping the input frequency and measuring distortion and noise we see quite a rise:
View attachment 42584

Distortion rises to almost 0.2% at 20 kHz! This is crazy high for any amp let alone an expensive one.

Headphone Listening Tests
I started my testing with the 25 Ohm MrSpeakers Ether CX headphones. That was a mistake. The HDV-820 produced the worst sound I have heard from them by far. It was distorted, lacked bass and dynamics and overall screwed up. Yes, that is a technical term. It is the opposite of not screwed up.

The situation drastically changed with Sennheiser HD-650 using 1/4 headphone jack. There was tons of power and dynamics. And whatever change the HDV-820 made in my short listening, seemed to be a positive.

Thermal Stability
Per our recent policy, I am testing devices for a few minutes until they get warm to see how they behave on distortion+noise. This is the HDV-820:
View attachment 42585

Yes, you are seeing what I am seeing. The channel in blue had a mind of its own just sitting there. Performance degraded as much as 5 dB on its own. There was no correlation with temperature during this 25 minute test. Probably not audible but sure demonstrated lack of good engineering.

Conclusions
At the US $2,400 price point I expect perfection. Sadly are not remotely there with Sennheiser HDV-820. The DAC is fine but stability is not. The headphone amp with its high impedance and hence low power/higher distortion makes this amp suitable for a small set of headphones. With many headphones you are going to experience a different sound than the headphone is meant to produce.

I think Sennheiser should take out the amp, license a THX amp and then they would have something proper. Even then, US $2,400 is a lot of money.

Needless to say, I can't recommend the Sennheiser HDV-820.

------------
As always, questions, comments, recommendations, etc. are welcome.

We probably not going to get sun for another 5 months here. Depression will likely set in soon and heaven knows you don't want me depressed. The only solution to it in my book is lots of money in my pocket. So please donate as much as you can using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/

Okay, that's shocking... just as B&W makes excellent speakers, Sennies makes excellent phones but B&W fails in making phones, and Sennies in making amps... if they excel in one product they may not necessarily excel in others despite their excellent brand name.

 

[JamesRF]

Nope.. it was a design error due to the cavity in the ring emitter. It was solved with a resonator that absorbs that energy in the HD800S.
In their own measurements (they use band noises) the 6kHz is hardly looking problematic.

where when measured with a different method the problem is clearly visible.

The HD800S shows the effectiveness of the resonator (the fix) vs the HD800:

I EQ the peaks (there is also one at 10kHz which is not seen but present in HATS measurements) out and raise the lows of the HD800 and there is nothing boring about the sound. It just isn't overly hyped detailed but exquisitely detailed.

With the right amplifier (enough output voltage swing) and properly EQ'ed bass the bass itself is not blaoted nor flabby nor distorted even at high SPL. The HD800 driver almost reaches planar levels in this regard.

Quite right. To my ear, the HDV820/HD800S remains one of the most satisfying headphone systems available. Having said that, I should add that I prefer the SPL Phonitor xe very slightly as a partner for the HD800S - to some extent because it has an analogue crossfeed circuit. It's of some interest to me that both amps seem to be regarded as underperformers on the measurement front. But perhaps they're both good enough in measurement terms.

 

[JamesRF]

A design error which held 20yrs until they fixed it? ....in Germany?? Come on........ They fixed it after 20yrs just because the crowd cried without knowing what they cried. "Give people what they want", .... and they "fixed" it.

The suggestion that there's a problem with the HD800/800S is simply wrong in my view. And, in any event, it seems like rank subjectivism to me. Many (including me) think its the best headphone on market. But I accept, of course, that others may prefer a different frequency signature. It is also, of course, a diffuse field reference - not fashionable these days.

 

[sprellemannen]

I purchased this along with the HD800s, and both digital and balanced analog signals sound superb.
Scientifically, a second unit would be tested for comparison

I would also have liked that a second unit would be tested.