[fhuang]

I believe headphones is always the cheapest device from the chain. plus dt880 is one of the better headphones around (a beyer fan here), also one of the hardest headphones to drive, so getting a more expensive device(s) can only do the beyer or any beyer some justice

 

[Edric Li]

There aren't many headphones tuned like 880 going up the price range. Try maybe the hifiman offerings, e.g. Susvara?

 

[Scrum92]

Quick thought: are the theoretical benefits of using optical over USB/coax lost if you keep a USB/coax connection into the Hugo 2?

 

[dmance]

Quick thought: are the theoretical benefits of using optical over USB/coax lost if you keep a USB/coax connection into the Hugo 2?

Q: remove a hot tray from an oven with two hands but only one mitt - without getting burned
A: use toslink alone, not in combination with a conductive interface

 

[Scrum92]

Q: remove a hot tray from an oven with two hands but only one mitt - without getting burned
A: use toslink alone, not in combination with a conductive interface

The problem with that comes down to DirectSound.

If I install the Hugo 2 USB drivers, I get pops/clicks when listening via DirectSound (so not bit WASAPI or ASIO). If I do not install the drivers, and just "plug and play" I do not get those. This is over USB to be clear. If I use optical, I get those same pops/clicks when listening via DirectSound and it's just frankly inconvenient because my PC is not only used to listen to music, it's also used for YouTube, Discord, Spotify in the background etc.

I had this very same problem with my old Mojo on my old PC and over in that thread it's a widely acknowledged issue. Apparently not on the side of Chord though I have not had this issue with other DACs in the past. I also had this same issue with the Hugo 2 on my old PC for the record.

My solution was to use USB (driverless) and swap to optical when I want to listen more seriously. I tend to spend an hour or so gaming with friends of an evening, then wind down to some music at which point I swap to optical.

Any thoughts on that?

 

[dmance]

...

Any thoughts on that?

If your are running Windows10, its native USB Audio 2.0 so any Chord DAC is plug-and-play WASAPI 'exclusive-mode' without driver install.

 

[Scrum92]

If your are running Windows10, its native USB Audio 2.0 so any Chord DAC is plug-and-play WASAPI 'exclusive-mode' without driver install.

Correct, and running play-and-play is fine for me over USB. I can use both exclusive mode and DirectSound without issue. But the same isn't true for optical, and being as Rob Watts suggests that is the "reference" out I'd like to use that if possible but I don't want to have to suffer pops/clicks when I'm casually using my computer.

Hopefully you see my conundrum?

I suspect the solution is to just live with USB. I can't confess I notice a difference, but that doesn't stop optical being objectively better. Audible or not there's a certain peace of mind that one might derive from that.

 

[dontfeedphils]

Correct, and running play-and-play is fine for me over USB. I can use both exclusive mode and DirectSound without issue. But the same isn't true for optical, and being as Rob Watts suggests that is the "reference" out I'd like to use that if possible but I don't want to have to suffer pops/clicks when I'm casually using my computer.

Hopefully you see my conundrum?

I suspect the solution is to just live with USB. I can't confess I notice a difference, but that doesn't stop optical being objectively better. Audible or not there's a certain peace of mind that one might derive from that.

You listen to that many sources on the same PC? Why not use a single program/source to listen through?

 

[111MilesToGo]

«If it sounds good, it is good!» A rule of thumb that has some merits. But sometimes it just misses the point, in that there may be better solutions for an even better result. In fact adding an amp to the Hugo₂ is a logical monstrosity – as already hinted by rkt31. You take the output signal from a DAC that you consider not good enough for your demands and lead it to another amplification stage with a complex array of electronics components, knowing (or being able to grasp) that no electronics component is 100% transparent and free of coloration. This in the hope that it will improve the signal. A logical impossiblilty. Well, there's still the hope that this configuration will at least provide a more solid drive for the dynamic load (I'm talking of the headphone). And you seem to see this hope confirmed by the sonic result – the keyword «authority» stands out.

Now this is exactly a confirmation of Rob's statement: «Some people like harmonic distortion.» He sometimes uses the term «phat» for the sound resulting from adding an amp to his products for driving headphones. I'm not just repeating his findings as a gospel, but have made my own experiments in the past (long before I was into Chord electronics), and it is no accident that I've landed with Chord electronics. What has convinced me apart from world-leading DAC technology is the concept of a signal path as direct as possible – for maximum transparency (see above). Now some people know better and find a recomplication of the signal path be the ultimate when it comes to sound quality.

The problem is that the resulting coloration can indeed make the sound subjectively more euphonic and spectacular. And particularly: more forgiving – to tonal flaws in the chain (thanks to the masking effect provided by the added harmonic distortion prone to make the sound richer and more colorful). Speaking of tonal flaws: They primarily address to the headphones with their inevitably nonlinear amplitude responses. The logical consequence of this insight is to use a headphone with a perfectly flat amplitude response for judging the quality of two signal-path variants. The inherent contradiction of the latter two points can be passably resolved with adequate equalizing of the headphone.

In short: For the comparison between direct path and detour via headphone amp you need to carefully equalize your headphone – individually for each of the two variants – to eliminate the tonal flaws that bother you beforehand.

From own experience I know what it takes to get the necessary «authority» from a headphone that may sound a bit thin out of the Hugo₂ and to make it counter the spectacular «phatness» of the amplifier route: Increase the low bass – something most headphones will benefit from.

I'm aware that this approach may be asking too much, given the appeal of amplifiers among audio enthusiasts and the «instant gratification» they may offer. My own experience has taught me to avoid them as much as I can. Note that it's less of an ideologic approach, but the result of extensive listening experience including comparisons under above premises.

Thank you, @JaZZ, for this great post. A good example of diligently sharing experience, without ideological distraction and offence. Here, we are on the field of personal impressions and delight, based on the principles of "everybody's got his own ears only, and his brains behind the ears"; on that field, one has to be careful and respectful. Your post for sure deserves a thumbs-up; that's what fora like this are for.

As I wrote above, I had formed my own opinion by carefully auditioning the H2 >> V281 >> HD800S chain, with and without the V281. I had arrived at the conclusion "yes, I want the V281 in it". Maybe that is an "if it sounds good, it is good", maybe that is a case of wishful thinking, maybe it is self-deception. But anyway, I have my V281 for more than a year now and continue to be happy. It was only recently that I found an article on the web by @twister6 published half a year ago (i.e. long after my findings!), who presents much better arguments in favor of externally amping the H2 in certain use cases than I can do. twister6 is on Head-Fi, and his article is here:
https://twister6.com/2019/05/13/adding-an-amp-to-chord-hugo2-good-or-bad/.
Unfortunately, I cannot judge on the basis of his arguing, i.e. his statements on the H2 electronic design: A DAC without an actual AMP. But SQ findings are in line: I used the word "authority", and this just matches twister6's findings with "heavy-weight" champion headphones and the H2.

Cheers, and thanks again for your input and attitude!

 

[Scrum92]

You listen to that many sources on the same PC? Why not use a single program/source to listen through?

That's what I want to do. I would like to use optical and optical alone but because of those pops/clicks when not listening via an exclusive mode I cannot.

I use Audirvana when I'm listening seriously but I also use my PC for gaming, Discord etc and pops/clicks just bug the s**t out of me.

 

[jarnopp]

That's what I want to do. I would like to use optical and optical alone but because of those pops/clicks when not listening via an exclusive mode I cannot.

I use Audirvana when I'm listening seriously but I also use my PC for gaming, Discord etc and pops/clicks just bug the s**t out of me.

You could get a USB to optical converter; one that is USB powered.

 

[Scrum92]

You could get a USB to optical converter; one that is USB powered.

I'd considered that.

Any recommendations / things to be aware of?

 

[111MilesToGo]

Your v281 has input sensitivity of 6dbu=1.55v. it has maximum power of 2.7w in 600 ohm which translates into whopping 40.25v into 600ohm. Assuming you use 11'o clock position it translates into 40.25x0.4= 16.1v (since v281 uses stepped attenuator, i take it as linear increment in resistance and 11'o clock as approximately 40% of full volume ). So do you think t1 will take 16.1v ? Now t1 has 102db per 1v sensitivity. So 16.1v translates into 102+20xlog(16.1/1) = 123db. So i don't think you would like your ear drums( or t1 drivers) to be torn apart with this kind of power. If at all you are using it at 11'o clock, you are using Hugo 2 at much much lower level, defeating any purpose of amp. Or if you are using v281 at 7to 8 o clock and Hugo 2 at 3v, then also you don't need an amp, you are just coloring the sound of Hugo 2. In any case you are degrading the Hugo 2 sound by heavy attenuation either in Hugo 2 or in v281.

@rkt31: Thanks again for taking the time to do some math. Since I am obviously neither blowing my eardrums nor my HD800S, I would like to be daring and share my approach to calculating the H2 >>> V281 >>> HD800S chain. I think you are looking at it from the perspective of "what power is deliverable" at the max. I take the differing route of looking just at voltages:

1. In line-out mode, the Hugo 2 outputs 3 V(RMS) as its maximum (@1 kHz), single-ended.
2. The V281 has a full output stage gain of +8 dB into SE, and +14 dB into balanced. It offers additional fixed pre-gain settings of -12, -6, 0, +6, +12 dB. I run my HD800S from the balanced output, with a pre-gain of -6 dB. This results in a net voltage gain of +8 dB in my case.
3. The volume pot of the V281 is typically set at 10 or 11 o'clock in my case - that's customarily considered ideal. Let's assume (as you did) that the volume pot is doing a linear scaling of the output voltage, i.e. 10 o'clock = factor of 0.3, 11 o'clock = factor of 0.4. Thus, for the 3 V(RMS) input from H2 to V281, the balanced voltage output is 3 V * 10**(8/20) * 0.3 = 2.26 V(RMS). [Background: The full gain of +8 dB = 20 * log10(U/U0) = 20 * log10(U/3 V), resulting in U = U0 * 10**(8/20) = 3 V * 10**(8/20) = 7.54 V(RMS); these 7.54 V get attenuated by 0.3 in our simplification.]
   
4. The HD800S has a nominal sound pressure level of 102 dB(SPL) @1 V(RMS) @1 kHz. Thus, the 2.26 V(RMS) input to the HD800S result in 102 + 20 * log10(2.26 V / 1.0 V) dB(SPL) = 109 dB(SPL). Remember, this is the calculational SPL in case the H2 outputs its full 3 V(RMS).
5. Finally, for simplicity, let's assume that typical audio levels are around 1/10 of the maximum voltage. The sound pressure level then is 102 + 20 * log10(0.226 V / 1.0 V) dB(SPL) = 89 dB(SPL).

Sounds very listenable, doesn't it? And I don't think an amplification (actually, a net decrease) of + 8 dB with another factor of 0.3 could be considered a "heavy attenuation" on the V281 side.

Please, any feedback on how I calculated the voltage amplification and resulting sound pressure level in this chain is very welcome. Thanks.

 

[jarnopp]

I'd considered that.

Any recommendations / things to be aware of?

I haven’t tried any, but the Matrix Audio has been mentioned on other threads, but I think it’s pricey. There are several available for around $20, so you could try that first.

 

[rkt31]

@rkt31: Thanks again for taking the time to do some math. Since I am obviously neither blowing my eardrums nor my HD800S, I would like to be daring and share my approach to calculating the H2 >>> V281 >>> HD800S chain. I think you are looking at it from the perspective of "what power is deliverable" at the max. I take the differing route of looking just at voltages:

1. In line-out mode, the Hugo 2 outputs 3 V(RMS) as its maximum (@1 kHz), single-ended.
2. The V281 has a full output stage gain of +8 dB into SE, and +14 dB into balanced. It offers additional fixed pre-gain settings of -12, -6, 0, +6, +12 dB. I run my HD800S from the balanced output, with a pre-gain of -6 dB. This results in a net voltage gain of +8 dB in my case.
3. The volume pot of the V281 is typically set at 10 or 11 o'clock in my case - that's customarily considered ideal. Let's assume (as you did) that the volume pot is doing a linear scaling of the output voltage, i.e. 10 o'clock = factor of 0.3, 11 o'clock = factor of 0.4. Thus, for the 3 V(RMS) input from H2 to V281, the balanced voltage output is 3 V * 10**(8/20) * 0.3 = 2.26 V(RMS). [Background: The full gain of +8 dB = 20 * log10(U/U0) = 20 * log10(U/3 V), resulting in U = U0 * 10**(8/20) = 3 V * 10**(8/20) = 7.54 V(RMS); these 7.54 V get attenuated by 0.3 in our simplification.]
   
4. The HD800S has a nominal sound pressure level of 102 dB(SPL) @1 V(RMS) @1 kHz. Thus, the 2.26 V(RMS) input to the HD800S result in 102 + 20 * log10(2.26 V / 1.0 V) dB(SPL) = 109 dB(SPL). Remember, this is the calculational SPL in case the H2 outputs its full 3 V(RMS).
5. Finally, for simplicity, let's assume that typical audio levels are around 1/10 of the maximum voltage. The sound pressure level then is 102 + 20 * log10(0.226 V / 1.0 V) dB(SPL) = 89 dB(SPL).

Sounds very listenable, doesn't it? And I don't think an amplification (actually, a net decrease) of + 8 dB with another factor of 0.3 could be considered a "heavy attenuation" on the V281 side.

Please, any feedback on how I calculated the voltage amplification in this chain is very welcome. Thanks.

I am afraid the calculation are not taking into account that the input sensitivity of v281 is limited to 6dbu which is 1.55v. so the pre amp section can't take more than 1.55v even if you set Hugo at 3v.