Review: Fosi Audio DS1 – The Energiser

D's Audio First Heart sounds very clean and dynamic with DS1.
D’s Audio First Heart sounds very clean and dynamic with DS1.

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The Fosi Audio DS1 provides bold and vibrant sound without compromising finesse.

Thank you to Fosi Audio for providing the DS1 for review.

DAPs may not be optimal for musical nirvana while on the go. Space, bulk, and weight constraints prohibit them from being used on a whim. A DAP with good quality sound is often the size of a regular smartphone, and carrying both on your person becomes impractical.

And that is precisely where dongle DAC/amps come in. In my experience, they can produce sound comparable to midrange DAPs, making them a default choice for on-the-go. Their battery consumption can be an issue, but having a power bank takes care of that.

Bottom Line

The DS1 is a surprising performer in a very compact and sturdy package - but with caveats. The metal build is prone to nicks and dents along the sharp edges. The weight is relatively high, considering the small size. The design is unimaginative and industrial, not exactly chic. The bundled cable feels low quality. But all of these negative aspects are overshadowed by the sound output quality. The DS1 makes music bold and vigorous, with no major compromises. Despite a slight lack of refinement, the whole presentation is amazingly captivating. It is rare to have both macrodynamics and microdynamics enhanced in such a balanced way. Fosi Audio has really hit it out of the park with the DS1.

What We Like 😍
  • Surprisingly powerful power output with low battery consumption
  • Neutral to warm tonality, highly transparent, but not thin sounding
  • Crunchy notes with prominent details
  • Great sound with impactful but clean bass, dynamic mids, and sparkling highs
  • Enhanced separation and airiness
  • Soundstage expanded quite well in all directions
  • Small size and sturdy build
What We Don't Like 🤢
  • Quite heavy given its small form factor, more than twice of its peers
  • Volume control is not independent – it controls source volume
  • Looks are very industrial, not chic at all
  • Sharp edges are prone to wear with regular usage
  • Slightly unrefined notes, a bit raw
  • The cable feels cheap

Dongle DAC/amps are now in high demand, and many big-name companies and fairly new brands are in the market to get a share of that cake. Fosi Audio is one of those new names; their first entry is the DS1 dongle.

The packaging is frugal; no unnecessary expense.
The packaging is frugal; no unnecessary expense.

Technical Specifications

  • Format: Portable DAC/amp
  • Output Power: 120mW(SE); 220mW(BAL)
  • Terminating Impedance: 16-300Ω
  • Input Mode: USB Type C
  • Output Mode: 3.5mm + 4.4mm Headphone
  • Frequency Range: 20Hz-20kHz (±0.5dB)
  • THD: 0.0006%(32Ω SE); 0.001%(32Ω BAL)
  • SNR: ≥120 dB
  • Sampling Rate: 32bit/768kHz
  • DSD: DSD64/128/256/512
  • DAC Chipset: ES9038Q2M
  • Material: Tin Alloy
  • Device Weight: 38g

Packaging

Fosi Audio has kept the packaging to a minimum, and I quite like that. A small cardboard box with foam cutouts houses the DAC/amp, accessories, some literature, and that’s it.

In the box

  • DS1
  • Braided type-c to type-c cable (120 mm)
  • Type-c to USB-A adaptor
Literature and components are tightly packed inside the compact packaging.
Literature and components are tightly packed inside the compact packaging.

Design

The DS1 is not much of a looker. The design is very ordinary and industrial looking. It feels surprisingly heavy for its small size – which instills confidence in the sturdiness of the build. The sharp edges, though, could be more user-friendly and are prone to wear.

The 3.5mm and 4.4mm ports are housed side by side at one end, and the opposite end houses the type-c port. The volume buttons are located on one of the longer sides, and a small LED is on the top.

I understand the bump accommodates the 4.4mm port without increasing the overall bulk, but it still negatively affects the aesthetics.
The matte finish of the components looks quite premium.
The matte finish of the components looks quite premium.

Internals

I am no stranger to ESS DACs in the budget bracket, such as the ES9218P, ES9218PC, ES9281PRO, etc. I was still waiting to experience the ES9038Q2M, which I had high hopes for coming from the ES9038PRO of the Shanling M7. Hence, the DS1 is a welcoming addition to my collection.

The DS1 offers playback of 32-bit/384 kHz PCM and DSD512 files with sampling frequencies of up to 5.6MHz.

The 120 dB signal-to-noise ratio is competitive in its respective price range.

The DS1 offers a high power output for the small size – 120mW @32 ohms SE and 220mW @32 ohms balanced. Quite impressive, and it should cover almost all IEMs, earbuds, and some full-sized headphones.

Battery consumption

The battery consumption of dongle DAC/amps is a notable aspect of their usability – you do not want your phone to run out of juice too soon while enjoying musical nirvana.

While connected to my three years old Samsung Galaxy M31S (6000mAh), playing on-board 16/44 FLAC files, and connected to a 32 ohm IEM/earbud, the DS1 only consumes 3% of my battery over 20 min – quite promising!

The 4.4mm balanced port looks significantly better than the 3.5mm single-end.
The 4.4mm balanced port looks significantly better than the 3.5mm single-end.

DS1 Sound

The DS1 injects ample raw energy into the sound, making the presentation alive and kicking.

As soon as I played the first song, I was immediately surprised by how much more dynamic it sounded! The tonality leans towards warm-neutral with an abundance of sparkle – making it quite pleasant yet somewhat flashy.

Bass slams hard and fast, with thick notes. Compared to other dongles in a similar price range, the bass notes are a bit bulkier but remain unobtrusive due to their speed. Midbass packs a strong punch, and sub-bass has a deep guttural response. The textures are plentifully pronounced as well.

Drums sound quite fun – powerful and snappy. Bass guitar and upright bass produce highly textured and authoritative rumbles that induce instant goosebumps!

The DS1 makes the midrange very rich sounding. The notes gain more body and depth, while the edges get accentuated as well. The result is a full-bodied midrange with detailed and crunchy notes.

The lower-midrange is the area where it gains the most body. Male vocals sound full, deep, and rich. The gritty textures become easily noticeable. Guitar, lute, and violin notes become full and sparkling. Female vocals are wonderfully zestful, and the weight feels realistic.

I have not encountered any other dongle DAC/amp that makes the midrange so vibrant and rich.

Cymbals gain a slightly forward presence, and they extend well enough. They might sound forced occasionally, but never too piercing.

The treble region has a healthy dose of energy and is full of brilliance and details. The notes have a noticeable bite that makes the presentation quite stimulating. However, they sometimes seem to lose refinement and come off as a bit raw.

The DS1 is technically reasonably competent, and textures are nicely reproduced. Details are highlighted, but due to the slight lack of refinement, they might occasionally sound forced. Soundstage has a decent width with decent depth and height. Imaging is well done as well.

The background is clean and dark. Separation and space between the notes are distinctly enhanced. But most importantly, the highly dynamic sound makes the DS1 an instant hit.

Check out my test tracks: male vocals, female vocals, instrument, sub-bass, midbass, and treble.
The volume control buttons have a nice haptic feedback and do not feel loose.
The volume control buttons have excellent haptic feedback and do not feel loose.

Comparisons

Vs. Hiby FC4

The Hiby FC4 is another ESS-based dongle DAC/amp, using two ES9219 chips this time. It offers playback of PCM up to 768kHz/32bit and up to DSD256 native. There is an LED status indicator for the types of files being played, unlike the DS1, which only indicates its operating status.

The FC4 has a longer but noticeably much lighter design (21g vs. 38g). The independent volume control of the FC4 is far superior to the source volume control of the DS1. On paper, the FC4 offers a slightly lower power via SE (110mw) but significantly higher power via the balanced output (340mw).

Soundwise, both are pretty comparable. The DS1 is more lively, with a darker, cleaner background and a bit more stage depth, but it is also slightly peaky. The FC4 is laid back in comparison and less clean, with a smidge more stage width. It sounds more refined than the DS1 but less alive.

Wear marks are starting to show along the edges after 2 months of continuous usage.
Wear marks are starting to show along the edges after 2 months of continuous usage.

Vs. Shanling UA3

An AK4493SEQ DAC chip and dual Ricore RT6863 amps power the Shanling UA3. It supports playback of DSD512 and PCM up to 32bit/768kHz. The LED status indicator indicates the types of files being played, unlike the DS1.

The UA3 is slightly shorter than the FC4 but is longer, wider, and somewhat thicker than the DS1. Despite the girth, it is lighter than the DS1 (20.5g). The UA3 also uses source volume control but comes with an additional play/pause button that is quite handy.

The power output of the UA3 is similar to the DS1 (125mW @32Ω through 3.5mm SE, 210mW @32Ω through 4.4mm balanced).

The UA3 sounds more refined than the DS1, with a slightly more spacious stage. The DS1 wins in macrodynamics – making the music more fun. Treble has a bit more energy on the DS1, but the UA3 has a bit more organic tonality, making the notes fuller sounding. Both are equally impressive for different applications.

The DS1 cleans up the Dark Matter's heavy bass and improves the dark treble.
The DS1 cleans up the Dark Matter’s heavy bass and improves the dark treble.

Where to Buy

Fosi Audio provided the following 10% off code: CAR10DS1.

Conclusion

The DS1 is a surprising performer in a very compact and sturdy package – but with caveats. The metal build is prone to nicks and dents along the sharp edges. The weight is relatively high, considering the small size. The design is unimaginative and industrial, not exactly chic. The bundled cable feels low quality.

But all of these negative aspects are overshadowed by the sound output quality. The DS1 makes music bold and vigorous, with no major compromises. Despite a slight lack of refinement, the whole presentation is amazingly captivating. It is rare to have both macrodynamics and microdynamics enhanced in such a balanced way.

Fosi Audio has really hit it out of the park with the DS1. I am hard-pressed to suggest another portable DAC/amp under USD $80 that is so enjoyable, not to mention its impressive power output via the balanced output – which makes the DS1 ideal for higher impedance/lower sensitivity loads.

The DS1 is a little powerhouse from Fosi Audio, and I love the complete package it delivers, with all its merits and demerits.

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