• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required as is 20 years of participation in forums (not all true). Come here to have fun, be ready to be teased and not take online life too seriously. We now measure and review equipment for free! Click here for details.

Sennheiser HDV-820 USB DAC & Headphone Amp Review

Joined
May 23, 2019
Messages
24
Likes
5
#81
Your samsung phone may have high output impedance and hence changes the response in a way you like. Then again I have an Samsung S8+ and no way does it sound as good DX3 Pro. It has anemic sound without good bass and dynamics with HD-650.

And no, Samsung is not quite poor unless you have measured it.
I'm just assuming it's poor based on other Samsung low end/ midrange phone audio measurements available online.

Another thing i want to note about distortion or aliasing issues in DACs is that if I chose NOS filter on DX3 and compare it to the best linear sharp then I hear no difference whatsoever but looking at the measurements you'd think it would be horrendous with it all bleeding back in to the audidble frequencies.
 
Joined
Oct 4, 2019
Messages
79
Likes
47
#83
That may be, but among the die-hard "measurements mean nothing to my ears" crowd, even a million tests wouldn't shake them one single bit.
I'm not a die-hard measurements mean nothing type. But as I said earlier, I've been using this amp for months and it sounds fine to me. Without these measurements I never would have known... Maybe I have bad ears. Maybe the bad performance isn't audible. Maybe this. Maybe that.
 

maxxevv

Major Contributor
Joined
Apr 12, 2018
Messages
1,648
Likes
1,624
#84
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!!!!
That Beyer amp doesn't actually pair very well with their own headphones. I tried it with the T1 and T5P and then used my cheap US$50/- portable DAC amp from China at CanJam. To my ears and even to the Beyer support staff (who out of curiosity tried my cheap DAC amp), the 2 headphones sounded "subjectively better" with my DAC amp. The Beyer amp sounded "peaky" and had a somewhat artificial tint/glare on some instruments at that session with the 2 headphones.

Maybe that's the "Beyer sound", that I'm not familiar with.
 

pozz

ЦАП
Forum Donor
Editor
Joined
May 21, 2019
Messages
2,303
Likes
3,253
#85
I'm just assuming it's poor based on other Samsung low end/ midrange phone audio measurements available online.

Another thing i want to note about distortion or aliasing issues in DACs is that if I chose NOS filter on DX3 and compare it to the best linear sharp then I hear no difference whatsoever but looking at the measurements you'd think it would be horrendous with it all bleeding back in to the audidble frequencies.
Right. But that's not really the issue. What I see here is a manufacturer that hides inaudible defects in an expensive device. As consumers we shouldn't be dealing with issues that should be settled by good, well-considered engineering well before we see the product.
 
Joined
May 23, 2019
Messages
24
Likes
5
#86
I'm not a die-hard measurements mean nothing type. But as I said earlier, I've been using this amp for months and it sounds fine to me. Without these measurements I never would have known... Maybe I have bad ears. Maybe the bad performance isn't audible. Maybe this. Maybe that.
It will sound perfectly fine it will sound very good infact, a lot of people highly rate the amplifier and people have also been loving listening to digital music since the 1982 and as you'd expect early CD players from back then wouldnt measure well.

The problem here as mentioned is the amount of money being charged for the specs, I think we know why, how does it look if sennheiser releases a $150 amp DAC to pair with its flagship multi thousand dollar headphones headphones.
 

NTomokawa

Addicted to Fun and Learning
Forum Donor
Joined
Jan 14, 2019
Messages
655
Likes
1,056
Location
Canada
#87
"Sounds fine" and "measures fine" are two completely unrelated things.

I've said this before and I'll say it again: I love (or used to since I no longer have the hardware) the occasional vinyl record through a tube amp. It "sounds fine", but there is not a single way that it could possibly "measure fine", especially when compared to the high-performance equipment measured here.
 
Joined
Oct 4, 2019
Messages
79
Likes
47
#88
"Sounds fine" and "measures fine" are two completely unrelated things.

I've said this before and I'll say it again: I love (or used to since I no longer have the hardware) the occasional vinyl record through a tube amp. It "sounds fine", but there is not a single way that it could possibly "measure fine", especially when compared to the high-performance equipment measured here.
Yes. They are two different things. That is exactly my point, thanks for reiterating it for me. :)
 
Joined
May 23, 2019
Messages
24
Likes
5
#89
Yes. They are two different things. That is exactly my point, thanks for reiterating it for me. :)
Your ears don't suck, enjoy it. What does suck though is how much you had to pay for it when you compare to a DX3pro.

I'm going to assume sennheiser used the same engineers when making the Orpheus HE1 as well.
So money aside im interested to see how that would compare as it's using the same ESS9018S.
 
Joined
Oct 4, 2019
Messages
79
Likes
47
#90
Your ears don't suck, enjoy it. What does suck though is how much you had to pay for it when you compare to a DX3pro.

I'm going to assume sennheiser used the same engineers when making the Orpheus HE1 as well.
So money aside im interested to see how that would compare as it's using the same ESS9018S.
Yeah. I bought it before I knew what all the other options out there were. I bought the HD820 and was looking for an amp and figured hey... Sennheiser says they "designed" this amp to pair with these headphones. I live in SF, where there is a Sennheiser store. And got to demo this combo together and it sounded good to me. I did buy the amp online though. I didn't pay $2400 for it lol...
 
OP
amirm

amirm

Founder/Admin
Staff Member
CFO (Chief Fun Officer)
Joined
Feb 13, 2016
Messages
28,223
Likes
72,998
Location
Seattle Area
Thread Starter #91
Going back to this measurement:



I am testing another headphone amp and found some other anomalies like this. Tracking it down, it appears to be related to how secure the headphone plug/jack are! I am confirming but for now, please don't run to Sennheiser and complain. :) These are extremely sensitive tests and are bringing things to surface that need more analysis and mileage on the test.
 
Joined
Oct 4, 2019
Messages
79
Likes
47
#92
Going back to this measurement:



I am testing another headphone amp and found some other anomalies like this. Tracking it down, it appears to be related to how secure the headphone plug/jack are! I am confirming but for now, please don't run to Sennheiser and complain. :) These are extremely sensitive tests and are bringing things to surface that need more analysis and mileage on the test.
How are you measuring this? Like... something plugged into a headphone jack? Something in an XLR jack on the back? If it's noise introduced by your test, that's certainly something to track down ;)
 
OP
amirm

amirm

Founder/Admin
Staff Member
CFO (Chief Fun Officer)
Joined
Feb 13, 2016
Messages
28,223
Likes
72,998
Location
Seattle Area
Thread Starter #93
How are you measuring this? Like... something plugged into a headphone jack? Something in an XLR jack on the back? If it's noise introduced by your test, that's certainly something to track down ;)
That one was with XLR in the back. Still, I want to double check such results when they show willingness as opposed to some trend that tracks in both channels.
 
Joined
Oct 4, 2019
Messages
79
Likes
47
#94
That one was with XLR in the back. Still, I want to double check such results when they show willingness as opposed to some trend that tracks in both channels.
Cool.

I don't even know why they have XLR output on this thing. It's not a DAC. I mean, it has a built-in DAC. But nobody is buying this thing to use as a DAC. It's a headphone amp. I've never actually used the XLR outs on the back. Just the XLR4, 4.4mm, and 1/4" on the front.
 

digicidal

Major Contributor
Joined
Jul 6, 2019
Messages
1,306
Likes
1,913
Location
Sin City, NV
#95
Cool.

I don't even know why they have XLR output on this thing. It's not a DAC. I mean, it has a built-in DAC. But nobody is buying this thing to use as a DAC. It's a headphone amp. I've never actually used the XLR outs on the back. Just the XLR4, 4.4mm, and 1/4" on the front.
Likely the primary reason it's there (as well as the front ports of every flavor) is to justify the MSRP. I doubt they expect even 5% of the end users to actually use this as a pre/dac - as you pointed out - but they also know that at $2400... there will be many "balanced everything audiophiles" who stopped their consideration as soon as it was missing XLR output. Considering the minuscule cost per unit associated with their inclusion... it's a no-brainer on the sales side of things.
 

solderdude

Major Contributor
Joined
Jul 21, 2018
Messages
6,232
Likes
11,448
Location
The Neverlands
#96
The HDV820 manual implies (never outright states) the output impedance is 16 ohms.
It just means the minimum impedance that should be used is 16 Ohm. This too is mentioned in the TPA6120A spec sheet when it is used at +/- 15V rails which is essential for driving 300 Ohm headphones. This is why there is 40 Ohm (4 x 10 Ohm) in series to limit the max output current. They are simply following the spec sheet of the otherwise fine performing TPA6120A
I have no idea why they mention the 16 Ohm as minimum though. Driving a 16 Ohm from 40 Ohm source impedance is not the wisest thing.
Also they state the amp is recommended for 300 Ohm headphones only (they also say 600 Ohm).

Regardless of this amp I don't think it says anything about Sennheiser's headphones, microphones etc.
To me it is audibly transparent and perfectly capable of driving the 300 Ohm headphone range from Sennheiser, certainly in balanced mode.
When new tests reveal there was a connector issue then I don't think it is defective.
 
Last edited:

JJB70

Major Contributor
Forum Donor
Joined
Aug 17, 2018
Messages
2,022
Likes
4,259
Location
Milton Keynes, England
#97
I'm not a die-hard measurements mean nothing type. But as I said earlier, I've been using this amp for months and it sounds fine to me. Without these measurements I never would have known... Maybe I have bad ears. Maybe the bad performance isn't audible. Maybe this. Maybe that.
In the case of DACs measured performance needs to be spectacularly bad before it becomes a real listening issue. There are numerous DACs which have measured poorly but which are perfectly fine for listening to music. For headphones amplifiers I tend to think if they can drive the intended load to the desired listening level and output impedance is OK for the headphones then unless they have been engineered deliberately for coloured sound most are fine.

That says two things. Firstly, even most DACs with poor measurements work fine in reality, and for most people differences between headphone amplifiers are basically insignificant if appropriately specified next to differences between transducers. So don't be put off your Sennheiser amp/DAC if you like it. Secondly, on the other hand the fact that it is hard to find a DAC that sounds sub-standard and headphone amplifiers tend to be fine is appropriately specified also means that in terms of sound quality these expensive devices are a bit pointless. However, they can be attractive if you value industrial design and build quality.

In the case of headphone amplifier performance, a hundred dollars can get you all the performance you will ever need and personally I see little point in most separate DACs unless you need specific functionality.
 
Joined
Aug 16, 2019
Messages
59
Likes
167
Location
Kingdom of the Netherlands
#99
You should see the Beyerdynamic A20 amp... it has 100 Ohm output resistance.
Edit: Nango beat me to it.

The justification is that they took the easy design route, grabbed the TPA6120A (Topping uses it as well) and designed it to comply to spec sheets which recommends 40 Ohm (single ended and run on high voltage rails) and specify a minimum of 10 Ohm output R which it has directly on the output of the amp to ensure stability.
The higher output R is of no consequence for the intended headphone range. It is not intended as a universal amplifier acc to them but strangely enough have several types of outputs that can be used together. Their story is a bit lame.

I don't think it is worth more than 400 Euros. They are selling dreams just like most other high priced brands and have imaginative writers that make up the nice stories around it.
Hi Solderdude,

I understand this technical reasoning quite well, but I don't think that the problem lies here.
Rather, for me the issue is that they don't have any disclaimer like:

"This device was specifically designed and only meant to be used in combination with headphones with a huge impedance like our HD 800, HD 820 and HD 650, and not with other headphones (like our HD 598). Customers are herewith warned that this device is not suitable for use with most headphones."

The absence of such a clear disclaimer looks like customer deception to me and I even wonder if that would not make them liable for a customer law suit in a country like the USA.

Is it true that they even don't put the (definitely abnormal and inacceptable for me) impedance of the amp in the specs?
 
Last edited:
Joined
Oct 22, 2019
Messages
7
Likes
9
Location
France
Another one bites the dust. Good job Amirm. The whole audio industry should be sweating. :facepalm:
 
Top Bottom