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Cozoy Aegis – portable DAC/amp


Recently I reviewed the Cozoy Astrapi, a tiny USB DAC and amp that works with computers, iPhones and Androids. Well, it seems the Astrapi was something of a tease of things to come because although the Astrapi is a fantastic, ongoing product, Cozoy have followed-up with a higher spec, higher quality product called the Aegis.


The Aegis is very similar to the Astrapi in terms of size and features, but they’re different in a few ways that really matter, the first of which becomes evident when we consider the specs.


  • Recommended headphone impedance: 16 – 100 ohms
  • Power: 60mW at 16 ohms, 35mW at 32 ohms
  • THD: <0.1% T 1kHz
  • Signal to noise ratio: 109dB at 3.3V power supply
  • Sample rates: up to 192kHz / 24-bit

If you compare the Aegis and Astrapi specifications there are some dramatic differences straight away. Firstly, the Astrapi peaked at 40mW making the Aegis 50% more powerful. Secondly, the Aegis will natively decode sample rates all the way up to 192/24 even from an Android device or iPhone. The Astrapi is capped at 48kHz, but can handle 24-bit.

It’s probably worth mentioning at this point that the Aegis is a higher priced offering compared to the Astrapi at $400 (AUD) compared to the $200 for the Astrapi. This obviously raises the question of whether the Aegis is twice as good for twice the price. Let’s find out.

Design & Functionality

Aegis-2823The link between Cozoy and Shozy is even more pronounced when you look at the physical design of the Aegis and this is some of the best work the machinists in the Cozoy / Shozy workshops have created to date. The Aegis shares a lot of design cues with the beautiful Shozy Alien with a nice cut-out on each side of the device and an angular design overall. Like the Alien, the Aegis still feels great in the hands with no sharp edges to worry about – the design and finish is beautiful.

The Aegis comes only in silver (as far as I’ve seen) and is made from high-grade aluminium with details such as a couple of stripes and some labelling all etched into the surface so it won’t wear off over time. At one end of the Aegis is a 3.5mm socket and the other end houses a microUSB socket, and that’s it – no buttons, no switches. The Aegis is as simple as it gets and that’s what makes it so compact and simple. This design simplicity makes the Aegis a tiny device – not quite as tiny as the Astrapi, but the difference is negligible.

One other point of note is that the fit and finish on the Aegis is the best I’ve seen so far from Shozy or Cozoy. All have been good, but the Aegis is excellent.


The Aegis will provide plug-and-play decoding with Android devices with OTG capabilities and with iPhones iPods via the lightning connector. I haven’t personally tested the Aegis with either device, but my first audition was from an iPhone and the process was as simple as it could be – plug in the cable, plug in the headphones and press play.

Other than portable devices, the Aegis will also work with Macs and PCs. If you’re using a PC there are some drivers to install and I must admit that the resulting driver options are a little confusing because the software from Cozoy means you will have more than one choice in your playback software. It’s not a big deal and I quickly found that some trial and error revealed the best option for my system, but it would be nice if there weren’t multiple options unless they are necessary, and if they are it would be nice to know which ones to use when.

Once the drivers are installed and you plug in, the small green-blue LED on the front of the Aegis will light to tell you it’s ready to go. From there you can play whatever files you like (up to 192/24) and enjoy fantastic sound quality from your PC, Mac, Android or iPhone.


The Aegis accessories are almost as simple as the Aegis’ design. You get the device itself and three cables – a microUSB to microUSB for OTG connections, a USB to microUSB for computer connections, and a lightning to microUSB for iPhone connections. That’s it and that’s all you need. A little soft pouch might have been nice, but it’s not a big deal.

Sound Quality

Power Output

The Aegis has the grunt to drive a reasonable range of earphones / headphones. It won’t drive power-hungry options like LCD-2s or Sennheiser’s 300ohm models (HD6x0 / HD800), but the Aegis is very capable with the lower impedance / higher sensitivity ‘phones on the market and sounded great when I first heard it with the Audioquest Nighthawks.

The result of the extra grunt in the Aegis’ amp stage is that it can be a bit over-powering with sensitive IEMs. This isn’t such an issue for computer use because there are often multiple ways to reduce gain via software, but iPhone and Android users will likely need to rely on higher quality playback apps in order to tame the volume level rather than relying solely on the hardware volume buttons on the phone / tablet.

As an indication of volume levels, I use JRiver MediaCenter on my PC and pull the gain back to 50% (-25dB) using MediaCenter’s in-built volume when listening via IEMs like the Noble Kaiser 10. This allows the main system volume controls within Windows to provide useful, incremental steps in volume. At 100% volume in MediaCenter, the volume is basically loud enough at minimum system volume so my PC’s volume control buttons become pretty useless.

On the other hand the Thinksound On1s are a good match with the Aegis and allow for a good range of volume control with plenty of power and authority in the sound from the Aegis. Generally speaking, the Aegis is great for efficient headphones with moderate impedance and is workable with IEMs depending on your software controls. Let’s see how it sounds…

A Couple of General Comments

Aegis-2822There are two things of note with the Aegis’ sound quality. Firstly, it will exhibit a slight amount of background hiss with sensitive IEMs. This is a common trait with some Shozy / Cozoy products and is a result of their design philosophy because they don’t filter the sound, preferring to keep the signal path as simple as possible to produce clean and natural sound. I don’t know if I agree with this approach entirely, but the hiss is so slight that I really don’t mind and I’m normally pretty picky about that kind of thing so it should tell you that it’s really a minor thing.

The hiss is subtle enough that you won’t hear it when you’re out and about so much as if you’re sitting in a quiet room using a computer. In those situations you can always attach an external amp using the headphone output like a line out (it’s not a true line-out, but it works fine) to negate the hiss and potentially upgrade the amplification power and quality (depending on your amp).

The second thing to note is that the Aegis creates a sharp pop when first powered up. It’s not the sort of pop that will burst your ear-drums or break your earphones, but it’s not the most comfortable sound and is best avoided by plugging in and powering up before putting your headphones on or your earphones in.

Finally, I wanted to share my initial experiences with the Aegis. Straight out of the box it sounded flat, lifeless and generally crappy. The good news is that it rapidly came to life during the first hour or two of playback so if you buy one of these, don’t be shocked when you first plug it in – don’t worry, it’s not a faulty unit. Just give it some time.


Aegis-2820The Aegis presents a really neutral sound signature with no noticeable emphasis. Where the Astrapi was fun and engaging because of its slight bass lift and gentle treble roll-off, the Aegis is a much purer sound and delivers what is essentially a transparent presentation. I love this because it lets me enjoy the earphones and headphones as they were originally tuned and that’s why I bought them. I still remember the Astrapi very fondly, but the Aegis is more my cup of tea.

Don’t for a second think that a neutral presentation means unengaging, cold or analytical. Quite the contrary – I find the Aegis highly engaging because of its transparency. It allows all of the details and nuances at every frequency to be clearly expressed with nothing overtaking the overall signature. Treble is crisp and clean, mids are weighty and lifelike, and the bass is punchy and present when the recording calls for it. This all contributes to the overall presentation of the Aegis which is equally enjoyable.


The Aegis has a highly coherent and spacious-feeling presentation. It doesn’t create a huge soundstage, but it creates a spacious soundstage. I seem to have been coming across many such presentations lately and every time I find this type of presentation thoroughly enjoyable because it is lifelike and natural with the ultimate result being an ability to get lost in the music and forget you’re listening to a recording. When you suddenly find yourself consciously picturing the venue or the studio because of the sonic image being presented then you know the DAC, amp, and ‘phones are working together perfectly to create truly great sound and the Aegis does a great job as both DAC and amp in this regard. With both the Kaiser 10s and On1s, the listening experience is completely engaging and immersive.

Cozoy Aegis vs iFi Nano iDSD

After really enjoying the sound from the Aegis, I thought I should conduct a short comparison test against another stellar performer in the compact DAC / amp market. Although the Nano iDSD is significantly larger and offers more features, both are excellent examples of portable DAC/amps. The Nano is actually cheaper than the Aegis, but the trade-off is size and that’s why the Aegis has been making the commute with me every day and not the Nano.

As for their sound, the Aegis is slightly leaner in the bass than the Nano which is where it’s clean and transparent sound comes from. I have to admit that it’s hard to say which device is truly more accurate to the source material. The Aegis presents a slightly drier treble, but that’s not a criticism as it may actually be more accurate. Both create a coherent and spacious stage that’s well-sized – not artificially stretched. The bass presentation is as subtly different as the treble presentation. The Aegis offers slightly less quantity in the bass, but the result is a perception of tighter, more detailed bass. That may actually be just a symptom of more mid-range and treble detail coming through in lieu of the extra bass, but either way the differences are subtle enough to be insignificant unless you’re conducting A/B tests like I am.

The conclusion is quite simple. If you have the budget, want something compact and don’t need DSD capability, the Aegis is the option for you. If you want to save some cash, don’t need something super compact and / or want DSD capability then the Nano might be better. As I said before, the Aegis is my “daily drive” because it adds nothing to the weight or bulk of my bag and that’s important for commuting on the train.

Summary & Conclusion

Next to the Shozy Alien, the Aegis shows just how tiny it really is

The Aegis proved itself to be an incredibly good DAC / amp in a tiny, tiny body. The Astrapi was good, but the Aegis is better without a doubt. Volume might be an issue for some users wanting to use sensitive IEMs, but with the right apps and software it’s easy to overcome this limitation. Beyond that, the only other hurdle might be the price, but keep in mind that this little, tiny work of art will transform your phone, tablet, or computer into an audiophile grade headphone driving machine.