Fosi Audio DS2 (2024 Cirrus Version)

★ Introduction :-

Fosi Audio was founded in 2017, They quickly gained recognition in the audio equipment market for their commitment to providing high-quality amplifiers and DACs at competitive prices. Fosi Audio products are known for their impressive build quality and sound performance. Their product range includes stereo amplifiers, headphone amplifiers, Bluetooth amplifiers, and DACs, among others. Affordability is on of their key selling point. That's why they aim to provide customers with excellent sound performance and reliability in their audio gear. Today I'm mainly here with the review of their new popular dongle DS2 (2024). I'll try to highlight all aspects of this dongle dac in my review. So that it is convenient for you to understand how equitable it is for this price category.


★ Disclaimer :-

I purchased DS2 dongle dac from Ali express store (Fosi Audio) . So I had no financial agreement with them to promote their product.The entire opinion of this review is totally my personal.


★ Box Content at a Glance :-

The unboxing experience of the device was similar to the other budget dongles. However, as necessary accessories, Type c to type c cable and type c to type A adapter is available, cable quality not the best but what is given cannot be said to be bad in any way, no extra type c to lightning cable is available out of box, If you want to get the benefits of lightning cable, you have to purchase a separate lightning cable.



1. DS2 dongle dac ×1
2. Type c to type c cable ×1
3. User manual guide ×1


★ Design, Build Quality & Functionality :-

The Fosi Audio DS2 Dongle DAC features a solid build construction with a compact size and durable design. This DAC is constructed by using materials such as durable CNC metal machining and the entire housing is made shock proof. As a result, its finishing has been beautiful as well as hand feel & usability has been added to a different level. It has a small LED indicator on the front side which basically changes to different colors according to the audio sample rate.
This dongle has physical volume control buttons, the placement of which seems appropriate and the button pressing gives fairly tactile feedback. As a budget dongle, there are no issues with the durability of the placement of ports and buttons on it. As I said earlier that it is compact size dac so it will be very compatible with phone, laptop & music player and even can be used without any problem. So I can definitely say that it is truly versatile enough to use.




★ Specifications :-

> Dac section : CS43131*2
> Output type : 3.5mm Single-End & 4.4mm Bal
> Input interface : USB - Type C
> Impedance rate : 16~300Ω
> Frequency response : 20Hz-20kHz (±0.5dB)
> Supports : PCM(32 Bit/768kHz) and Native DSD256
> SNR : ≥130dB
> Noise floor : <1μV
> Dynamic-range : 125dB (SE) & 130dB (BAL)
> Output power : 130mw@32Ω (SE) & 510mw@32Ω (BAL)
> Output level : SE - 2Vrms & BAL- 4Vrms
> Harmonic distortion THD+N : 0.0006%(SE) @32Ω & 0.001% (BAL)@32Ω


★ Tasted With Gear :-

~ Sony IER M9
~ Tanchjim Origin
~ Dunu Falcon Ultra
~ Simgot EA1000
~ KiwiEars Quintet
~ Hidizs MP145
~ Tinhifi P1 Max ii
~ Kinera Celest Phoenixcall



★ Sound Aspects :-
The DS2's tonality ranged from neutral to slightly warm which added an analog-ish character to the overall sound.

The whole sound presentation was matured, as a budget dongle I did not see any bass or treble roll-off related issue. Even, it does not add much coloration to the sound. it was fairly clean, neutral to warmish type signature.

Also the interesting part of this dongle is the output power as it is capable of delivering (510mw@32Ω) power from its Bal port which is really remarkable from such a budget dongle dac. From regular DD to demanding Planar IEMs & Headphones, everything can be powered up fairly well.


I've used a number of IEMs in my reviews but haven't tested any headphones because I don't think this dongle suitable for demanding headphones drive . I got noticeable distortion whenever I tried to increase the volume level to use IEMs on it. But only in the case of IEMs, it will not cause such a big problem, but according to Fosi audio, the advertised high power output was not fully justified in my opinion.

Let's talk about its bass at the beginning, sub bass to mid bass section was nicely separated & well controlled without any tendency to bloat. However, there is a slight boost in the sub bass region, due to which the hi-hats of snare drum are given extra emphasis, which is not unpleasant to hear. On the other hand, the mid bass has been smoothed a little and warmth has been added, as a result, the definition of the bass notes has become a little weaker. So the heavy hitting sound of the kick drum has suffered a bit.

The mids section was very clean, there was no unwanted boost, so the tone of the artist's voice was very natural. The body of male & female vocal was very nicely represented , there is no problem of making it thin or recessed but the organic character of cirrus logic house sound which is usually observed, in the case of mids was also present here. Thither adds a slight warm to the mids and overall a bit forward to the presentation of mids region.

Treble section condition was quite improved. Electric, acoustic guitar & violin have been able to deliver the sound of string instruments as vibrant and well balanced. I have not noticed any lacks anywhere. Every instrument has been delivered in a very nice smooth manner without making it overly sharp, aggressive or dull. As usually found in Cirrus logic house sound, I found some similarities in the treble performance.

As opposed to, technical aspect was pretty good . Descent amount of detail, micro detail can be found very easily from here and at the same time there was fairly wider sound stage and depth. Imaging can accurately portray and the stereo presentation was solid. So I don't find any major flaw. As an entry level dongle dac, it has technically been able to give better results.


★ Synergy and Power :-

Most of the IEMs had better synergy with the dongle of neutral to warmish sound, moreover, there is no shortage in terms of power output and battery consumption rate is very low. I'm using it with the phone at 50-65% volume level (Bal port). Then its heat management and battery efficiency was very admirable .
Although, Single ended output was also good comparing others dongle, dynamics was somewhat lacking on single ended but nothing to room complain as long it was musical to my ears. However, using too bright sounding IEMs will not give the desired results. I paired my tested gear items with it and got pretty good results especially the IER M9.

Pairing was surprisingly good with m9. IER M9 itself is warmish neutral. Fosi audio ds2 doesn't exhibit any kind of hints of sibilance, that is a positive side of ds2. On the other side ds2 is also slight warmish on nature so the bass and mids on m9 section was slightly smooth with rounded yet exerting enough detail for it's asking price. Bass was little elevated maybe due to its amping design. Imaging and stage was a bit mediocre level. In short ds2 is on smoother side with well-rounded sound that is very suitable for enjoyable listening that many people seek.


★ Comparison :-

~ Moondrop Dawn Pro
(50$)~

Dawn pro basically neutral to slightly bright Sounding dongle dac. It has its own app support and 100 step volume level works very accurately. However, its bal port power output max 120mw but the output power is clean even at full volume and no distortion is found. Moreover, the build quality is low, the physical button pressing feedback is a bit loose and the stock type c to type cable is of very cheap quality.

Vs ~ Fosi Audio DS2 (60$)

DS2 Sound more analog-ish than Dawn pro. At the same time, DS2 is in a better position in Sound stage, Imaging, separation and layering. Moreover, build quality, accessories and button control feedback are slightly better and power output is far ahead compared to dawn pro. But the biggest difference is that the Ds2's sound isn't as more resolving and by no means suitable for heavy demanding gear use as Fosi Audio is advertising. Because when the volume level is increased, noticeable distortion is found in the sound. However, the notes of the sound were quite thick and rounded, so the sound of the full body was obtained, on the other hand, the sound of the Dawn pro was somewhat less musical and weight of the notes was less fuller , but the presentation was completely distortion free.


★ Conclusion :-

The current Dac dongle market is very competitive. Almost all chifi brands use popular off-the-shelf DAC chips and use their in-house R&D and try to attract the audience. Similarly, Fosi audio has launched several products in their affordable price category and DS2 in the 60$ price range will be a very good option for those who like thick and well-rounded sound with a hint of warmth & analogish character. And for those who prefer a bit bright-analytical and highly detailed sound and if the budget is 100$ then EPZ TP50 dongle dac can be an ideal choice for them, so from my side I would suggest buying both for people who are used to different sound signatures.

I've provided purchase link below for everyone's convenience

Fosi audio Ali express store (link isn’t affiliated)

and Hifigo (link isn’t affiliated)

FOSI AUDIO is an audio company that quite reflects its solid reputation as an audio brand whose products offer exceptional sound quality, superb performance and good build quality at affordable price for budget-conscious audio enthusiasts. This audio company offers a variety of products from desktop preamps up to DAC/amp USB dongles. I actually publish some reviews of their products before and you can check it out at the end of this assessment



What I have here that will be featured here in this review content is their latest DAC/Amp USB dongle, The FOSI AUDIO DS2. Like most DAC/Amp dongles that were available in the market, this device follows its usual form factor like elongated rectangular structure, a metal alloy chassis, type-C port and different types of audio jack interfaces.



As I mentioned that it has a metal alloy chassis, it seems that it underwent a CNC-milling process to achieve that uniform construction to have a firm and solid build with a sand-blasted finish on its surface in a gunmetal colour scheme to exude that premium-feel while maintaining a lightweight profile. Among the USB DAC/Amp dongles that I've tested, The FOSI AUDIO DS2 is probably the most compact size with a good balanced weight on it.



In both ends, it has a USB type-C port while its opposite side, that's where the two types of headphone port interface are situated, the 3.5mm single ended and 4.4mm balanced output. On the side panel, there are volume key buttons for volume control which have independent functionality depending on a music player app's settings.



At the top panel, there's a RGB LED indicator for sampling rate and type of digital audio format.



Here are the following colour-coded display:



Regarding its internals, it uses an older generation of Cirrus Logic, the CS43131 in a dual configuration. This DAC/Amp is a 32-bit 2-channel audio DAC that can decode up to 384KHz sampling rate on PCM and DSD256 on DSD format which makes it a high performance audio chip. This particular audio chip is actually very reliable and very power efficient to deliver a hi-fi sound with low distortion, high signal-to-noise ratio and better dynamic range to deliver a clean, transparent and stable sound quality. The built-in amplifier of this IC has a maximum power output up to 2Vrms which is enough to drive some of the most power-demanding headphones out with an impedance of 600 ohms.



This device has a detachable type-c to type-c short cable and its wiring strands are twisted.

Regarding its product packaging, FOSI AUDIO DS2 is very simple with meagre inclusions.



Here are some contents inside of its packaging box:

• FOSI AUDIO DS2 dongle
• Type-C to type-C cable
• User's manual
• USB type-C to type-A adaptor

Regarding its hardware and software compatibility, this device can be used on devices such as smartphones, tablets, laptop and desktop. And for software, it can support both desktop and mobile operating systems. Windows, Mac OS and Linux on desktop OS, and then Android and iOS on the mobile OS although in older iPhone models, you need a lightning to type-C cable. In Android OS apps, there are few music player apps that can support USB audio access to bypass the android OS audio sampling like Hiby Music App, UAPP (USB Audio Player Pro), Neutron App and Onkyo HF player.



As for its tonal profile, it seems that like almost all devices with Cirrus Logic DACs, this device has a warmish-neutral sound that it has a tad textured lows and mid frequency and a rather linear high frequency which makes this set more appealing to audio enthusiasts who wants a more analogue-ish sound signature.




LOWS/BASS:

This device is capable of delivering a well-defined punchiness, tactual and slamming bass response even if it was paired with more neutral-sounding sets with tighter and lightly thump bass, it can add some texture to it.

It can give a satisfying deep rumbling and reverberating sub-bass presence generated from instruments such as low tone bass guitar, bass violin, synthesisers and drum machines. It adds some density on note weight that might affect the tonal colour and characteristics on some instruments like bass trumpets, bass guitars, viola, bass clarinets, bass kick drum and a particular type of male voices like bass and bass-baritone vocals.


MIDRANGE:

The midrange quality of this one is quite well-textured as it has a hint of warmth that gives some depth and volume of vocals and instruments to sound at least more natural. Another thing that I also observe is that it has some transparency and a tinge of energy that will be more convenient on some female vocals, then a hint of crisp and brill on strings and woodwinds.

On male vocals, baritones have some smooth and plush sound while tenors have brassy and clear vocals. Countertenors have this opaque, coppery and tender vocals which share similar tonal characteristics with female mezzo-sopranos. Contraltos sounds almost correct on this one as it has a sufficient amount of richness and hefty on its vocal quality and then on sopranos, it has creamy and silvery that makes them even more captivating and mesmerising to listen to.

As for instruments, it sounds quite natural with a good amount of detail and clarity. On string instruments, there's a balanced to meaty sound on the guitars especially on the acoustic ones and a full and lustrous sound on violins. A rounded, full and intense sound on brasses like trumpets, trombones and horns. Then on woodwinds, it has a clear, rich, expressive and reedy sound on piccolos, flutes, clarinet and saxophones. As for percussive instruments, the tom-toms and field drums have a full, reverberant and warm sound, a hard and clattering sound on snare drums, and a resonant and rumbling sound on kettle drums. The piano sounds even and balanced as it has a bright and mellow tone with sufficient resonance.


HIGHS/TREBLE:

The treble quality that this device able to evince on my listening session, it has a smooth, evened and linear treble response with an unusually amount of sparkle and airy extension that most devices with Cirrus Logic DACs that I've quite familiar with, this device is quite a peculiar one.

Somehow it gives a more lustrous and full sound on cymbals and a short buzz and sizzle sound on hi-hats. A sweet and velvety sound on celestas and a bell-like sound on glockenspiels.


OVERALL TECHNICALITIES:

This device is able to project a fairly spacious soundscape with excellent height and depth that pairing it with warm-sounding sets gives that immersive and intimate feel but on IEMs and headphones with superb technical performance, it narrows a bit on the perceived distance. It still has an excellent layering on the placement of instruments and vocals with good separation on each element in a black sonic canvas.

In terms of resolution capabilities, this device is quite resolving on both macro-dynamics and micro-dynamics. It has a solid and firm texture on its dynamics as it has a proper compression while it has a good micro-detail retrieval as it is able to pick up on some subtleties like vocal ends, spatial reverberations and distinctive nuances of different instrument attacks.


PEER COMPARISONS:

TRUTHEAR SHIO

• This USB DAC/Amp dongle, like the DS2 is also equipped with Cirrus logic amp albeit a newer generation, CS43198. Its size is a bit larger compared to DS2 and yet it has similar weight, its surface was covered with PU leather and unlike the DS2, it has manual gain switch mode by pressing between the volume key buttons.
• On the tonal aspect, it also has a warmish-neutral sound profile like the DS2. Both have slamming and tactile bass response, a tad warmth on the midrange and a slight emphasis on upper-mids up to the presence part to give a little bit of energy with good airy extension and sparkling sound. Both sets have eerily very similar technical performance like moderately spacious sound/speaker stage projection, well-defined layering and separation and remarkably resolving on their own right. Although, I think that SHIO still has a more powerful output that can drive most of the stubborn and power-hungry headphones that demand more juice.

EPZ TP20 PRO

• Another dongle with Cirrus logic DAC with the same model IC. It has a broader frame compared to the DS2 as it is also carbon-fibre cover on the top and bottom panel. In additional features, it has a toggle switch and additional button key for pause and play function. And also, its stock cable is quite thicker and even a bit longer and of better quality.
• The TP20 PRO is also of a warmish-neutral side of tonality as it exhibits similar sound profile with DS2 albeit its treble response seems to less emphasis on upper-mids and presence part to give that smoother, a less energetic with just enough sparkle and a noticeable modest airy extension. Both devices have very similar performance of technical abilities as it is almost impossible to differentiate the differences between these devices. It also appears that both sets have similar power output delivery but on paper, DS2's power output has a maximum rating of 510mw at 32 ohms at its balanced output jack.

In summary, this DAC/Amp dongle is quite a performer and FOSI AUDIO continues to impress us on every release of their product. This DAC/Amp dongle shows that we can enjoy a high-fidelity sound quality in a compact and mobile form factor that it became more of a necessity for audio enthusiast like us given the removal of analogue features on most smartphone that deems “obsolete” for today's digital era according to these mobile phone companies (In which I'm still firm and adamant on disagreeing these notions). If you want a USB DAC/Amp dongle with some element of an analogue-ish tonal profile as it has a musical and fun factor that make it more engaging with competent technical capabilities, this might be the device that you are looking for.

FOSI AUDIO DS2 is now available in HIFIGO, you can check out the unaffiliated link below.


★★FOSI AUDIO DS2 - HIFIGO★★


Also, you can check out my previous review article of FOSI AUDIO products.


■ FOSI AUDIO MC101

■ FOSI AUDIO SK02




SPECIFICATIONS:



MY TESTING TRACKS: ( * = 16-bit FLAC, ** = 24-bit FLAC, *'* = MQA, '*' = DSD, *'= .WAV)

Alison Krauss -When You Say Nothing At All *
Jade Wiedlin - Blue Kiss**
Led Zeppelin - When The Levee Breaks **
Mountain - Mississippi Queen *
Queen - Killer Queen **
Guns N' Roses - Patience *'*
Eric Clapton - Tears in Heaven '*'
Sergio Mendes- Never Gonna Let You Go '*'
Pearl Jam - Daughter **
Roselia - Hidamari Rhodonite *
Assassin - Fight (To Stop The Tyranny)*
Celtic Frost- Visual Aggression *
New Order - Blue Monday *
The Corrs- What Can I do (unplugged version) *
Jimi Hendrix Experience - Voodoo Child *
The Madness- Buggy Trousers *
Metallica - Motorbreath **
Mariah Carey- Always Be My Baby *
Destiny's Child - Say My Name *
Malice Mizer- Au Revoir *
Mozart - Lacrimosa *
New York Philharmonic Orchestra - Dvorak- Symphony 9 " From the New World." *
Eva Cassidy - Fields of Gold (Sting cover)*
Michael Jackson - Give In To Me *
Exciter - Violence and Force *
Diana Krall - Stop This World **
Debbie Gibson - Foolish Beat *'*
The Sisters of Mercy – Lucretia My Reflection**
Suzanne Vega – Luka **
Lauren Christy – Steep *
Ottoman Mehter - Hucum Marsi *
Diana Damrau - Mozart: Die Zauberflöte*


P.S.

I am not affiliated to FOSI AUDIO nor receive monetary incentives and financial gains as they provide me a review unit for an exchange of factual and sincere feedback from yours truly.

Once again, I would like to send my gratitude to HIFIGO especially to Ms. Lvy Yan for providing this review unit. I truly appreciate their generosity and trust towards me and other reviewers.

Fosi Audio DS2 Dongle DAC Amp

For those who don't enjoy reading...

---

DS2 (2024) Specifications & Product Details (Fosi Audio Website)

Fosi Audio DS2 2024 New Mini Audio USB DAC Headphone Amplifier​

---

Unboxing (Photos)

---

Build & Design

The first thing you'll notice when taking this thing out of the box is that it's incredibly light, at 15.5g without the cable and 20.2g with the cable.
It’s not exactly class-leading in that regard, but neither is it a heavyweight.

Hanging off the phone or stowed away in a pocket, the dongle hardly feels heavier than the rest of the cables and plugs it is connected to, which is vastly more reassuring than my previous experience with the DS1 which feels like a brick by comparison.

On the flip-side, I don’t get as much confidence from the thinner metal of the DS2 housing that it could survive more than a few drops or getting possibly bruised by a heavy water bottle in a backpack.

In any case, I think you simply have to decide what kind of dongle suits your needs best; the heavier and sturdier, or lighter and possibly more fragile.



Like the DS1, and many other dongles it has two different coloured sockets, which at the very least can be considered an easy visual way to distinguish between the 3.5mm and the balanced 4.4mm.

Once again I’m more than happy to see the continued implementation of a detachable USB-C cable.
Since I’ve been using these twisted rope-type cables for a while now, I’m getting more convinced that they are a long term solution, as they have a bit more stretch and compression than other cables, and are practically immune to twisting.



The provided USB type A to C adapter still has the same finish as the cable connectors and are are also finished in the same colour as the DS2 unit itself, making them an obvious visual pairing.

The volume buttons remain unchanged using the same old symmetrical design, so in the pocket it is not obvious which button is volume up and which is down.
When used with a computer or laptop, with the USB cable leading away from you, the volume buttons are in the intuitive positions.

Overall the build is satisfactory. After a couple of weeks I have noticed a few small marks starting to appear on the surface of the metal, so it’s not impervious to wear and tear.

I’m a little disappointed to see that the buttons are still the same.
I would have liked to see an asymmetrical button layout implemented, with one button being longer or larger than the other. Over time one could then use the volume controls automatically without looking at the unit.

---

Functionality

The DS2 has a few different LED colours.

The Blue LED simply tells you when it’s connecting to a device like a phone or laptop. Normally you will only see blue for a moment.
Then you’ve got red for PCM playback up to a sample rate of 48KHz, green up to 96KHz and orange up to 384KHz



Other than that there isn’t much to it.
This dongle appears to be made for ultimate simplicity and user-friendliness.

The downside to this for some may be that there is no volume indicator.
Another issue is that holding down either of the volume buttons does not raise or lower the volume quickly.

You have to press the volume button manually many times to reach either extreme.
This won’t be an issue for most users who control their system volume through the operating or their media player directly, or their mobile phone system volume.

Also there is no companion app, so for some this will be a negative point, while others will prefer the plug and play simplicity.

---

Measurements and Sound

Overall with my ears I can’t detect any significant change in the sound quality or tone from the Fosi Audio DS1, SK02 or my other amps.
In my previous DS1 review I already determined that most of my amplifiers and dongle had no obvious measurable effect on a Sennheiser HD650 seated in the same position.

However in this instance, the DS2 has actually made a small and unexpected difference.



While my other amps all produce graphs that almost perfectly overlay on top of each other, the DS2 has some minor deviations between 1000 and 6000hz.

The only significant change is a 2dB scoop between 2 and 3KHz.
Practically with some headphones this can actually reduce glare from instruments and vocals that sound too far forward or prominent and improve the sense of soundstage.

It’s not a bold tuning by any means, but neither is it objectively bad or distasteful.
On the contrary, to the most golden of ears, this may be a welcome change.

Personally, I can barely hear such a minor difference, so for me that’s a plus in it’s own way, since I prefer my headphones or EQ settings to do the work, but at most it may give the slightest feather touch more warmth to the sound.

---

Comparisons

The main comparison I want to make is between this and the DS1.
Going back and forth between the DS1 with it’s ESS ES9038Q2M chips and the DS2 with it’s Cirrus Logic CS43131 DAC chips, I really wanted to hear a glaring difference.

I’ve got plenty of experience listening to music from various sources with ESS and Burson chips so I happy to report that there are no obvious differences from the Cirrus Logic chips.

For me DACs continue to be the least interesting aspect in the audio chain; which is EXACTLY how I would want things to remain.
It’s already confusing enough having hundreds or even thousands of different flavours of headphone and IEM, which is compounded by the subtleties of amplifier design.



I’m happy to say that the absence of additive flavourings was consistent throughout various headphones, flathead earbuds and IEMs.
The DS2 had no trouble driving either extremely sensitive IEMs without adding even the slightest hint of background noise, nor driving highly demanding full sized planar headphones.

The objective result of using these Cirrus Logic DAC chips specifically in the DS2 actually have further benefits.

According to the marketing on Fosi’s website the DS2 uses “Low-power Technology”, and from the time I’ve used it on my phone, I think might actually consume less power than the DS1 so unlike the DS1, the DS2 also never got warm to the touch.

Automatically you might think “OK, so it uses less power, so it must be a weaker amp” and you’d be wrong.
The new 2024 model with the Cirrus Logic chips is over twice as powerful as the previous DS2 model and the DS1, and can reach ear-splitting volumes out of it’s regular 3.5mm output.

The balanced output is more than capable of adequately driving some of the more demanding headphones around today.

Whether it ends up consuming more power the more demanding headphones and higher volume you use is still up for debate as I have not tested this, but I think it would be more than fair to assume that would be the case.



Conclusions

I’m not sure what Fosi Audio is doing here because I feel like they’re undercutting themselves with the new DS2.
It’s lighter, more powerful, more user-friendly than the DS1, and cheaper.

I think anyone looking for their first dongle DAC amp should take a very serious look at the 2024 DS2.

It’s balanced output power of 510mW into 32 ohm is quite frankly an insane achievement for such a small dongle, easily rivalling the power of many entry and mid level desktop sized headphone amps.


I’ve noticed a running theme starting to occur with Fosi Audio.
POWER
All their recent products have been aimed at bringing as much clean, usable power to the user as possible for as little money; and this is by far no exception.

The DS2 obviously won’t give higher end desktop amps a run for their money; it doesn’t offer quite the same musical performance as my NFB11.28 or SK01, but for the size and weight, it’s actually kinda nuts.