AudioQuest Dragonfly Cobalt Review (Portable Headphone Adapter)

[Jimbob54]

Send Amir a Nordost product and I am sure he will review it. I'd love to see how the "mechanically tuned construction" of these compare to the zip cable I use.

That would mean a member admitting to having bought one.

 

[DSJR]

Did I say "most"? - Yes I did, and I was deliberately flaming .....I might one day have a real go at Linn (it's a swear word here. ref the court case) &.... AMS Trading, post the Sugar lump's budget HiFi separates.
OK, that company from Denmark was a cracking dealership to have (partner's late father was very well rewarded) once they were beyond their 'Which?' IIRC accolade for the most self-immolating colour TVs per number sold.
I'm old enough to remember the 'piano key' tuner amp (1965?) that they refused to let anyone test.
I had a 1962 EMG year book with a B&O ad featuring a tape recorder with .......a ..... BSR deck!
It was thus probably their most reliable tape machine ever, though hardly high-end.
There's more, but I'm way off topic.

I think I know where you are and that it's way off topic As for Linn, I was always fond of the Thorens 150 and as the LP12 is basically a 'blue-printed' and 'enhanced' TD150 (the RD11 may well have stolen that basic design/layout and the 'other one' appropriated it?)....... Piano key tuner-amp - 3000? That was poor in IMD, the 4000 was reviewd and rather better and the 4400 the last in that styling was excellent and a proper bit of audio receiver for the late 70's.

Anyway, it looks as though Audioquest are becoming the new 'Monster?' Here we have the Chord Company which started off making cables DIN to RCA for Naim amps, but now selling a wide range of wires from good value (bought from a dealer taking their large profit) to ridiculous... Thank heavens for Amazon Basics amongst many others...

 

[Billy Budapest]

What really gets to me about this product is that it has great noise, jitter, and frequency response performance, but terrible distortion. The noise and jitter performance seem to indicate that Audioquest got the power supply and D/A conversion aspects correct. However, the audio output circuit design is most probably where the deficiencies lie. Then again, that’s probably the hardest circuitry to design.

 

[John Atkinson]

What really gets to me about this product is that it has great noise, jitter, and frequency response performance, but terrible distortion.

I examine this in my own review of the DragonFly Cobalt, in particular examining the maximum levels that are possible without high levels of distortion into different impedances: https://www.stereophile.com/content...obalt-usb-da-headphone-amplifier-measurements

I wrote in the review's listening section: "When the Cobalt is required to drive lower impedances, the volume control has to be backed off to avoid clipping the DAC's output amplifier."

John Atkinson
Technical Editor, Stereophile

 

[Deleted member 31473]

This is a review and detailed measurements of the AudioQuest Dragonfly Cobalt portable DAC and headphone amplifier ("dongle"). It is on kind loan from a member and costs US $300.

The Dragonfly Cobalt dates way back to when these dongles came in the form of USB flash Thumb drives:

View attachment 127584

This makes it easy to connect to desktop and laptop computers (assuming yours has such USB connection) but needs a chunky adapter to connect to USB-C on phones and tablets. While I did not have it, a custom one comes with Cobalt which makes a secure connection.

The dragonfly series comes in a few colors, each with a different performance level. The Cobalt is the top of the line as indicated by sky high price for such a product. An ESS ES9038Q2M DAC chip is used internally as to indicate high performance. We will check for this.

AudioQuest Dragonfly Cobalt Measurements
I was pleased that the Cobalt introduces itself to Windows in a way that I could use my ASIO interface layer and as such, run my full suite of tests (which half the time I can not). Let's start with our dashboard:

View attachment 127585

Looks pretty bad. It actually looked far worse before I subtracted 1 dB from the digital input signal. Without it, it was heavily clipping with SINAD dropping to below 30! As it is, the Cobalt turns in one of the worse distortion ratings as encapsulated in SINAD that I have tested:

View attachment 127586

The one to its right, Speaka, is one of the first dongles I ever tested. I think it cost just $30 or something. Sweeping the input level we see the full range of performance:

View attachment 127588

You can see that performance is best when the output is low and progressively gets worse until it hard clips. Just unacceptable.

Surprisingly, noise level is quite good:

View attachment 127589

Distortion is the problem as we see in multi-tone test yet again:

View attachment 127590

DAC filter is slow, ala MQA style:

View attachment 127591

I don't know how they consider 6 dB droop at 20 kHz acceptable. Testing with a square wave shows the "benefit" or no pre-ringing but with clipping as the filter rings:

View attachment 127593

Notice the flattening of the tops of oscillations. And that is at -2 dBFS input signal!

Linearity test is nailed showing once again, there is some good in this DAC that is obscured by other parts:

View attachment 127592

Jitter test shows very good results for a dongle as well:

View attachment 127594

Dragonfly Cobalt Headphone Amplifier Measurements
Most important measurement for these dongles is power. Phones and tablets often struggle to drive fancy headphones so the job of these products is to remedy that. Let's start with 300 ohm load:

View attachment 127595

Distortion rises very early one starting at a fraction of a milliwatt -- totally unacceptable. Fortunately because the output level reaches to 2 volts, we do have good bit of power for a dongle:

View attachment 127596

Performance drops much more with a 32 ohm load:

View attachment 127597

View attachment 127598

Compare the 26 milliwatt to recently reviewed THX Onyx. The Onyx produces 132 milliwatts compared to just 26 for Cobalt and does it at far lower distortion.

Dragonfly Cobalt Listening Tests
The Cobalt had no trouble driving my Sennheiser HD-650 to good levels of loudness and authority. There was not much to complain about in the context of a portable dongle. Switching to Ether CX headphone though, was a completely different situation. Turning up the level beyond a whisper would cause the bass notes to distortion. At max volume, the output was severely distorted and unusable.

Conclusions
As the category leader, AudioQuest takes advantage of their market position to price the Dragonfly Cobalt sky high. Unfortunately it then proceeds to deliver a highly distorting product that has little ability to drive low impedance headphones. You can buy plenty of products at one third of its price that way outperform it. If you want a brand name, get the THX Onyx which washes the floor with it. Whoever designed the headphone amplifier in this product needs to go back to engineering school or pay attention to what the competitor is shipping. Actually he needs to do both.

While with high impedance headphones, the AudioQuest Dragonfly Cobalt has acceptable subjective performance, it fails in so many other ways that I cannot recommend it.

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

Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/

Thank you for the review, and I did comment on YouTube about it. Although I have never purchased this it still makes me a bit angry. I’m not accusing AQ of resting on their laurels, because in my opinion they never had them to rest on. That’s about as negative as I’m going to get about it.

I would love to see their high-end cables measured hint hint hint LOL. I know our host has measured one before, I forget which one it was but it had some kind of a bug zapper attached to it. Honestly I’m not sure if it would even kill bugs but I’m pretty sure it would break my RCA connectors off. All kidding aside I am thrilled that I resisted all the nonsense that’s out there. Well kinda.. except for eight turntables that I own I’m doing OK

 

[Deleted member 31473]

That would mean a member admitting to having bought one.

 

[bobbooo]

But oddly, many current phones don't have a headphone jack, so you have to use a dongle anyway.

As I said previously in this post, this is not actually true. Here is an updated list of the top-selling phones over the last couple of years:

Every single one of the non-Apple phones above has a headphone jack. Then there are big-name brands such as Sony, Motorola and Nokia who have brought back headphone jacks to their flagships, as well as smaller brands like ASUS very recently.

In fact, GSMArena.com has a brilliant phone finder tool that can finally settle all this with actual data (this is a science-oriented forum after all). Filtering by 'Available' this tool shows 1,966 models. Further filtering by '3.5mm jack' only reduces this number to 1,605 models. So that's 1605/1966 = 82% of phones currently available to buy that still have a headphone jack. Limiting this to Android phones (to disregard Apple models which obviously don't have the jack) pushes this up to 84%. This data clearly contradicts the oft-repeated but never backed up 'obvious fact' that almost no modern smartphones have headphone jacks (or even that many don't), when the truth is only a small minority of 16% of current Android models lack a jack.

Why do so many continue to erroneously believe this proportion is much higher? I can only imagine they've fallen for all the marketing propaganda pumping out the nonsense that the 3.5mm jack is dead, in order to either promote sales of Bluetooth headphones, or high-power 'audiophile' dongles like this Dragonfly Cobalt, when the truth is the latter (and for me the former, but I can understand others disagree on that) are a solution without a real problem, and come with added drawbacks - decrease phone battery life, extra bulk, easily lost or damaged, don't allow simultaneous charging and headphone listening, potential compatibility problems with devices etc., not to mention additional cost (the latter of course being the real driving force behind this marketing, to milk more money out of their gullible, hyper-consumerist target audience).

The vast majority of smartphones with headphone jacks will have enough power to drive the vast majority of IEMs / portable headphones with reasonable sensitivity to safely loud levels. For the small minority that don't, get a better phone / a more than ridiculously insensitive IEM or headphone - there are plenty out there to choose from. And for insensitive full-sized home-listening headphones, we have a plethora of powerful, audibly transparent desktop amps for them.

Apart from the Qudelix 5K with its very useful hardware parametric equalizer for system-wide EQing from any source (as well as its in-built battery that will actually extend max listening time instead of decreasing it), I just don't see the use case for these high-power dongles that lack such features. I suspect the vast majority who buy them will end up having them lying on a desk where a full-sized amp could do a better job without sliding about, or never use even close to all the power they provide with their portable headphones / IEMs, for which one of the 1,605 currently available smartphones with a headphone jack would do just as good a job.

 

[GDK]

Why do so many continue to erroneously believe this proportion is much higher?

Because the iPhone’s market share in the US is around 40%, and that is before LG exited the smartphone market. Showing that there are available models with a HP jack is interesting, but it is total sales that matters as that represents the market. That said, at least half of the phones sold in the US (those were the easiest stats to find on a 2 second Google hunt) still have a jack.

 

[amirm]

Every single one of the non-Apple phones above has a headphone jack. Then there are big-name brands such as Sony, Motorola and Nokia who have brought back headphone jacks to their flagships, as well as smaller brands like ASUS very recently.

Big names? Are you kidding? None of those brands have any market share in US. Most don't even sell a phone here anymore (e.g. Nokia). Even worldwide they are MIA. As for the table you post, a bunch of those are not flagship phones. Samsung A series for example are all mid-tier phones.

Top phone brands worldwide (outside of China) are iPhone, Samsung and Google. Google only has one phone with headphone jack. Samsung's flagship phones do not. I know, I just looked to see if I should replace my Samsung S8+ and there simply is no choice available from any manufacturer.

For all intent and purposes, headphone jack is history in top-end phones with LG departure.

 

[mansr]

Let's get this back on topic with some PCB photos.

 

[Kegemusha]

Big names? Are you kidding? None of those brands have any market share in US. Most don't even sell a phone here anymore (e.g. Nokia). Even worldwide they are MIA. As for the table you post, a bunch of those are not flagship phones. Samsung A series for example are all mid-tier phones.

Top phone brands worldwide (outside of China) are iPhone, Samsung and Google. Google only has one phone with headphone jack. Samsung's flagship phones do not. I know, I just looked to see if I should replace my Samsung S8+ and there simply is no choice available from any manufacturer.

For all intent and purposes, headphone jack is history in top-end phones with LG departure.

I have the Samsung Note 9 (Same for the S9) they have headphone jack and a good DAC inside. So a S9 would be a good alternative.
New good mobiles with headphones could be LGV60, Motorola Edge and Edge Plus (Mote Edge is High end phone for what I can see) , Google 4a and Xperia, Oppo Nord too if you dont have iphones.

 

[bobbooo]

Because the iPhone’s market share in the US is around 40%, and that is before LG exited the smartphone market. Showing that there are available models with a HP jack is interesting, but it is total sales that matters as that represents the market. That said, at least half of the phones sold in the US (those were the easiest stats to find on a 2 second Google hunt) still have a jack.

Yeah a typically blinkered anglo-/USA-centric perspective plays a role here in forming this false belief. Why only consider the US? But even given that restriction it's faulty thinking for the topic in question. Market share is not what matters here. The argument I refuted was 'hardly any phones have headphone jacks these days, therefore you have no choice but to use dongles'. This is demonstrably false as the above data from GSMArena's phone finder tool shows. In this case it's availability of phones with headphone jacks that matters, not how many have sold. People just need to open their eyes and look beyond their Apple (or Google or Samsung) bubble. For example, it's literally as simple as typing nokia.com into your browser to find their headphone-jack adorned phones readily available in the US. Then there are flagship models with headphone jacks from solid brands like Sony and Motorola available.

I have the Samsung Note 9 (Same for the S9) they have headphone jack and a good DAC inside. So a S9 would be a good alternative.
New good mobiles with headphones could be LGV60, Motorola Edge and Edge Plus (Mote Edge is High end phone for what I can see) , Google 4a and Xperia, Oppo Nord too if you dont have iphones.

Yep, then there's the Samsung Galaxy S10 series, including a smaller more handleable S10e version (which I have), a larger S10+, and even a 5G variant, which are still great, plenty-fast and powerful phones today with audibly transparent DACs. For the vast majority of users, there's no need in spending ridiculous amounts of money for the very latest flagship when they will never even approach the limits of their chipsets (only really useful for hardcore mobile gamers or mobile video editing, which are pretty small niches). And yes the LG V60 (including a 5G ultra-wideband variant with mmWave support, the fastest 5G available) is still a great option with fantastic audio capabilities, especially now LG have promised 3 years of full Android version updates.

 

[raistlin65]

Yep, then there's the Samsung Galaxy S10 series, including a smaller more handleable S10e version (which I have), a larger S10+, and even a 5G variant, which are still great, plenty-fast and powerful phones today with audibly transparent DACs. For the vast majority of users, there's no need in spending ridiculous amounts of money for the very latest flagship when they will never even approach the limits of their chipsets (only really useful for hardcore mobile gamers or mobile video editing, which are pretty small niches). And yes the LG V60 (including a 5G ultra-wideband variant with mmWave support, the fastest 5G available) is still a great option with fantastic audio capabilities, especially now LG have promised 3 years of full Android version updates.

"Need" is always an interesting topic to bring up in an audio forum where many of us regularly buy audio equipment that we don't *need.*

An interesting thing about phones is that many apps do increase in processing power needs through subsequent upgrades of the apps. I just upgraded my S9+ to an S21+ partially because one of the apps I regularly use was now acting sluggish in the most recent upgrade. And the upgrade wasn't as expensive as you might think because I got $350 trade in on the S9+. Had I instead gotten the S8 back then, the trade in would be have been minimal and the app sluggishness more of a problem.

 

[Matias]

Let's get this back on topic with some PCB photos.

View attachment 128019

View attachment 128020

Bottom pictures has written "by JGR@WA", [edit] J. Gordon Rankin at Wavelength Audio.

 

[Svperstar]

I used to have the Dragonfly 1.2, was great for portability, just stopped working one day. Good for its time(2015) better products now.

 

[bobbooo]

I used to have the Dragonfly 1.2, was great for portability, just stopped working one day. Good for its time(2015) better products now.

Nope, it was also poor for its time (Archimago's measurements):

Beaten by Samsung's audibly transparent Galaxy Note 5, released way back in 2015. There's nothing more portable then the phone that's already in your pocket.

 

[Svperstar]

Beaten by Samsung's audibly transparent Galaxy Note 5, released way back in 2015. There's nothing more portable then the phone that's already in your pocket.

One is a phone. The other is a USB DAC, not a fair comparison. Pointless argument though for such a dated product.

 

[raistlin65]

One is a phone. The other is a USB DAC, not a fair comparison. Pointless argument though for such a dated product.

I know. And yet the phone still managed to do better.

 

[phoenixdogfan]

Gordon Rankin wrote code for asynchronous USB audio transport. I believe it w called “Streamlength” and was licensed to a lot of different audio manufacturers. Not sure if I’d call him a “guru” or “pioneer,” but his implementation was popular and I am sure he made a lot of money from the licensing fees. He makes very beautiful looking DACs and sells them from a pretty ugly website:

https://www.usbdacs.com/products/

Actually more famous for his Wavelength Cardinal a 4 Wpc single ended triode tube amp which certain "audiophiles" maintain reproduces that all-important "first watt" perfectly.

 

[Raindog123]

I will admit, I am a former owner of a Dragonfly Cobalt... In Jan 2020, I finally decided to expand my 30+ years of speaker-based music enjoyment and bought a pair of Grado SR-325e‘s and a Cobalt. I mostly listened Tidal over my iPhone 8 and/or iPad. To address the battery issue, I dusted off my wife’s old iPhone battery bank and bought a generic ($11) USB “camera” splitter, which worked like a charm. I did like the sound - both Redbook and MQA titles were fine...

...And then I joined ASR. This is where I learned that a $300 for the pleasure I was getting was way too much, and there are better alternatives. So, I sold the Cobalt (after over half year) and bought EarMen Sparrow (for $200). The one with both single-ended and balanced outputs and the one they market as ”sparrows eat dragonflies for breakfast”. I liked the sound through my easy-to-drive Grado’s... but then (1) I bought more demanding HifiMan HE-400i’s, (2) @amirm finally measured the Sparrow, and @IVX came up with his (~$100) E1DA 9038D...

Bottom line, I learned it first-hand. Cobalt is not too bad, especially for easy loads. But not for $300. And better sounding and measuring under-$100 options are there today. And a USB/Lightning splitter, even a no-name, easily solves the limited iPhone power issue. And a stationary DAC+headphone amp setup might be even better, but it's a different story...