FOSI AUDIO DS2

INTRODUCTION
The Fosi Audio DS2 version 2024 represents the current most popular portable DAC dongle trend of using a dual CS43141 chip, just like the Moondrop DAWN Pro I also own, so I'm going to base much of my review on a comparison of these two portable DACs.

SOURCES
I typically listened via USB Audio Player Pro in exclusive (Bit-Perfect) mode to files from the TIDAL streaming service, and local files in FLAC format.

PRESENTATION

The DS2 came to me in a small, simple package, packed securely in foam, sitting by itself in a cutout that fits the size. It comes with a thin black-gray USB-C - USB-C cable. Here I would like to point out the first similarity to the Moondrop Dawn Pro i.e. the cable from Moondrop, which, despite being a bit thicker, (it spreads by 1-2 mm) overall is very similar. The main difference is the way the USB-C ports are mounted. In the case of Dawn, the ports are flooded with some kind of resin, which allows for minor movement of the connector itself and can cause signal dropouts over time. In the case of DS2, the port is rigidly mounted in a metal housing and shows no tendency to bend, which I think may carry over to a longer lifespan. Unfortunately, I would classify both cables as fragile, and given the portable nature of using these dongles, I would expect something more durable. An example of a good solution in my opinion is the cable from Kiwi Ears Allegro, which is 2-2.5 times thicker and gives a greater sense of durability, so I'm hoping it will allow longer enjoyment of this product. Fortunately, in case of problems, such a cable can be easily obtained from an external source.
In addition, the kit comes with a USB-C to USB adapter, and that would be it.



BUILD

As for the appearance and construction of the dongle itself, although it is quite similar to the Moondrop Dawn Pro, it is about 1cm longer than it, about 1mm thicker, but about 2mm narrower. However, there is one important difference: the DS2 from Fosi Audio seems to be more solidly built than the Moondrop Dawn Pro. At the time of writing this review, the dongle from Moondrop no longer has a volume control button because it collapsed inside the case, which I, unfortunately, can no longer open because it was loose from the first days of use and I had to glue it down – ehhhh, famous Moondrop QC. DS2 performs much better in this aspect. The dongle is solid, nothing is loose inside and in general, there seems to be nothing to break in it.
Congrats, Fosi Audio, that's how it should be.

The volume control buttons work flawlessly and allow you to change the volume on a 60-degree scale, so you're more likely to find your “sweet spot.”

PERFORMANCE FEATURES

The Fosi Audio DS2 2024 uses a very popular recent module consisting of two flagship Cirrus Logic chips model CS43131.
According to the manufacturer's declarations, we can count on an output power of 130mW for the 3.5mm port and as much as 510mW for the 4.4 balanced port (!!!).
Signal-to-Noise ratio, or signal-to-noise ratio, or in other words, the audio signal quality index here is 130dB, which is very good, because the higher the value of this parameter, the usually better the quality of the signal itself. We now live in an era where levels above 100dB are also quite common in such small, portable devices, and it's great that the DS2 doesn't disappoint in this aspect either. The SINAD, or Signal-to-Noise and distortion ratio, which is the ratio of the total signal-to-distortion energy and noise, is as high as 109dB here, which of course is also a very good result.

SOUND AND COMPARISON

Once again, since I own a very similar dongle, the Moondrop Dawn Pro, in the sound section I will try to present a direct comparison from listening to both of these dongles, but before that, I would like to convey something important:
Both dongles show a very good quality of reproduced music, and power fully sufficient to drive all the iems I have (including the planar Letshuoer S15), and the differences I was able to pick up were minor enough to go unnoticed without critical, detailed listening. I am confident that a potential buyer will be satisfied with any of these devices, and the following comparison is only meant to make the choice easier.
I will start my direct comparison of these dongles with the sound presentation.
In the case of the Fosi Audio DS2, I had the impression that the sound was softer, devoid of sharp edges, and smoother. In the case of the Moondrop Dawn Pro, at times I got the impression that, especially in the high registers, the sounds were rougher - more pronounced. In a direct comparison, however, I had the feeling that with the DS2, the sounds of drum cymbals, for example, were more natural than with the Dawn Pro, where this sharpness took them away from naturalness. As far as technical capabilities are concerned, I think both units perform very well, and only the increased sharpness I mentioned above may cause an impression of more detail in the Dawn Pro's sound, but it's not a big difference. As for the reproduction of the lower registers, I had the impression that the DS2 is a bit more bass-heavy than the Dawn Pro, with the emphasis also mostly on sub-bass. The bass in the DS2 fills the head more, while the Dawn Pro focuses more on the impact of the sound. As for details, I got the impression that more of them were picked up by the Dawn Pro, but I'm not fully convinced that this is an advantage, because at times the amount of sound distracted from the main line of the song, and after all, that's not the point of hearing all the details, but the song as a whole.
To check the output power, I used a 75Ohm impedance adapter, and with my Letshuoer S15 planar connected, the max volume was definitely above the level of normal listening, so we don't have to worry about lack of power here. 

A few more words about the differences from the Moondrop Dawn Pro

1. no gain mode switch

The Fosi Audio DS2 2024 does not have a gain mode switch. From listening, I got the impression that it operates in high gain mode all the time, but I am not sure. Pressing the + and - buttons at the same time did not cause any change in sound.

1. no dedicated application with filters and EQ

Fosi Audio DS2 2024 is a pure dongle with a cable and buttons to change the volume - that's it. Moondrop Dawn Pro allows you to control the device from the dedicated Moonkdrop Link app, where you can: adjust the volume, change the gain mode, the possibility to apply 4 pre-installed sound filters and EQ with the ability to, among other things, import presets (Android only), for example, from Squiglink pages. In my opinion, this is a shortcoming that, for those interested in these capabilities, may be a deterrent to buying the DS2. Fosi Audio should consider introducing such an application, especially because its competitors (Moondrop, Tanchjim) already have them and are constantly improving.

SUMMARY

To best illustrate the differences, I have decided to compile them into tabular form below:

CONCLUSIONS

As conclusion, I can once again say: both devices offer very good sound reproduction quality and enough power to calmly drive most, if not all iems available on the market. With a fairly similar price, the main differences that a potential customer should consider are the quality build of the device, where the DS2 excels, and the functionality associated with the dedicated application that Moondrop has. The choice will depend on the user's needs and expectations. For my part, I think this is a very good dongle and I can confidently recommend it as a portable budget DAC.