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:
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:
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:
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:
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:
Distortion is the problem as we see in multi-tone test yet again:
DAC filter is slow, ala MQA style:
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:
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:
Jitter test shows very good results for a dongle as well:
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:
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:
Performance drops much more with a 32 ohm load:
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/
The Dragonfly Cobalt dates way back to when these dongles came in the form of USB flash Thumb drives:
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:
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:
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:
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:
Distortion is the problem as we see in multi-tone test yet again:
DAC filter is slow, ala MQA style:
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:
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:
Jitter test shows very good results for a dongle as well:
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:
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:
Performance drops much more with a 32 ohm load:
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/