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Fosi Audio DS2 Portable DAC & Amp Review

Rate this portable DAC & HP Amp

  • 1. Poor (headless panther)

    Votes: 3 1.0%
  • 2. Not terrible (postman panther)

    Votes: 4 1.3%
  • 3. Fine (happy panther)

    Votes: 8 2.6%
  • 4. Great (golfing panther)

    Votes: 287 95.0%

  • Total voters
    302

amirm

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This is a review, detailed measurements and listening tests of Fosi Audio DS2 portable DAC and balanced headphone amplifier. It was sent to me by the company and costs US $55.
Fosi Audio DS2 Stereo Portable DAC and Headphone Amplifier balanced amp review.jpg

Well, it looks like a dongle. :) The LED seems to indicate the sample rates. What I like is inclusion of 4.4mm balanced drive and hard button volume controls:

Fosi Audio DS2 Stereo Portable DAC and Headphone Amplifier balanced amp volume control review.jpg


Let's measure it and see where it stands.

Fosi Audio DS2 Measurements
Let's start with the balanced output:
Fosi Audio DS2 Stereo Portable DAC and Headphone Amplifier Balanced Measurement.png

Wow! I did not expect this level of performance! We are talking good desktop class DAC output here with SINAD that tops the chart of all portable devices I have ever tested:

Best portable stereo dac headphone amp review.png


Unbalanced output is naturally limited to 2 volts:
Fosi Audio DS2 Stereo Portable DAC and Headphone Amplifier unblanced Measurement.png

Even this performance is great with highest level distortion at -120 dB (below threshold of hearing).

Good news doesn't stop there. Check out the dynamic range:
Fosi Audio DS2 Stereo Portable DAC and Headphone Amplifier Balanced dynamic range Measurement.png


Once again it competes with some of the best desktop headphone amps:
best dac for IEM headphones review.png


The quietness manifests itself even in the filter test:

Fosi Audio DS2 Stereo Portable DAC and Headphone Amplifier Balanced filter Measurement.png


Low distortion shows up well in multitone test:
Fosi Audio DS2 Stereo Portable DAC and Headphone Amplifier Balanced Multitone Measurement.png


Jitter is in the same class:
Fosi Audio DS2 Stereo Portable DAC and Headphone Amplifier Balanced Jitter Measurement.png


Above tests were static so I could drive the unit properly. For sweeps, my analyzer output gets distorted through the driver translation layer so please ignore the noise level in these power tests:
Fosi Audio DS2 Stereo Portable DAC and Headphone Amplifier Balanced Power 300 ohm Measurement.png


most powerfull headphone amp dac dongler 300 ohm review.png


Fosi Audio DS2 Stereo Portable DAC and Headphone Amplifier Balanced Power 32 ohm Measurement.png

most powerfull headphone amp dac dongler 32 ohm review.png


As we see, power output is excellent as well.

I noted on the first graph the idle power consumption being around 0.4 watts (at 5 volts). When playing music, it shoots up to 1.7 watts or so.

Fosi Audio DS2 Listening Tests
I started with the Sennheiser HD650 high impedance headphone. The DS2 drove it with no difficultly, producing excellent fidelity and bass impact. Higher power desktop amps push it a notch higher but what was there was plenty enough with some headroom left to play with. I then plugged in my difficult to drive Dan Clark E3 headphone and was very surprised when the DS2 drove it with no hint of distortion. It was perfectly usable on the DS2 -- something I rarely say for a portable product.

Conclusions
The Fosi DS2 blows away the objective barriers for a portable DAC and headphone amplifier, producing desktop class noise and distortion. Hard to imagine this little device doing that but it clearly is, and doing it at such a reasonable cost! It really redefines the category. Usability is excellent with hard button volume controls. Really, don't know what else to say other than be mindful of power consumption which shoots up to 1.7 watts when playing loud.

If you are short of space, the DS2 can easily play the role of a desktop DAC.

It is my pleasure to recommend the Fosi Audio DS2 portable DAC and headphone amplifier.
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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/
 
Reserved for @AdamG to kindly post the specs.

Manufacturer Specifications:

IMG_0794.jpeg
 
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Dang, Fosi is really not letting Topping rest easy. Pretty impressive, very impressive for the money. The multitone in particular looks great... the only drawback is it's going to chew up your phone's battery, but at least you know that juice is in service of TOTL performance. :D

This will be at the top of my list if I find myself needing a (decent) portable DAC. Right now I'm using some very questionable dongle I got at the airport...
 
We're getting there. Have to wonder how much longer before we have contact lenses that produce IMAX images together with IEM's and haptic onesie tactile subwoofers to render 24 channel Atmos Netflix programming. And all affordable enough to be bought with a miniscule portion of our monthly UBI direct deposits! Great way to take in The Dark Knight, part 24 on a park bench.

As always, terrific review, Amir.
 
Terrific, I wonder how Moondrop Dawn Pro compares (same dual CS DAC)
Edit, forgot it's been measured:
 
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Why you want eq on the dongle, you have eq on on your source device surely?

You can often find this cheap in the multitude of aliexpress deals/savings that come around every so often, it was shown with discount down to £30/$40 a while ago, I should’ve bought it…..don’t really need it but still……..I should’ve bought it :facepalm:
 
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@amirm : you might not be aware that there exist two versions of the DS2: one with ESS ES9018K2M, one with Cirrus CS43131. Both versions use dual DACs and seem to provide the same power. Now which one did you test?

On Fosi's website they label one DS2 2023, the other DS2 2024, with a small price difference.

Of course trying to shop online there is zero indication what you get. Sellers even mix up the description badly, like 'DS2 adopts ESS Technology CS43131 DAC Chip'.

Edit: answered in post #15.
 
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A big thank you to Amir for the review. :D

The DS2 is one of our products as we make our entry into the high-performance DAC market. The DAC market is filled with many outstanding companies with which everyone is familiar. We will humbly learn from these companies as we continue to grow, and we hope to follow in their footsteps by bringing Fosi Audio’s unique touch to DACs for audiophiles worldwide. In addition to portable DACs, we’ll soon be introducing a desktop DAC as well.:cool:

To show our appreciation for the support from ASR members, we’re offering a special discount code for the DS2. You can use this code to get 20% off your DS2 purchase!;)
ASRDS220

link:
https://fosiaudio.com/products/fosi-audio-ds2-2024-dac-headphone-amplifier
https://www.amazon.com/dp/B0CTHN2QB3
https://www.amazon.de/dp/B0BJ66KJ2B
https://www.amazon.com.au/dp/B0BJ66KJ2B
https://www.ebay.com/itm/296311456320
 
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@amirm : you might not be aware that there exist two versions of the DS2: one with ESS ES9018K2M, one with Cirrus CS43131. Both versions use dual DACs and seem to provide the same power. Now which one did you test?

On Fosi's website they label one DS2 2023, the other DS2 2024, with a small price difference.

Of course trying to shop online there is zero indication what you get. Sellers even mix up the description badly, like 'DS2 adopts ESS Technology CS43131 DAC Chip'.
The version Amir reviewed is the 2024 one with Cirrus Logic CS43131. The 2023 one is off sale. :)
 
We're getting there. Have to wonder how much longer before we have contact lenses that produce IMAX images together with IEM's and haptic onesie tactile subwoofers to render 24 channel Atmos Netflix programming. And all affordable enough to be bought with a miniscule portion of our monthly UBI direct deposits! Great way to take in The Dark Knight, part 24 on a park bench.

As always, terrific review, Amir.
Absolutely! We’re all on board with the idea that VR and AI are fast-tracking us toward that wild future. At Fosi Audio, we’re doing our best to keep up, bringing some innovations to the audio world—of course, staying true to our high-value roots. Just recently, we launched a four-channel amp HT4S, and some of our users have already hooked up two of the channels to bass shakers for haptic tactile. Sure, it’s not exactly cutting-edge sci-fi, but hey, we’re doing what we can to make that immersive experience a little more... 'shaking'! ;)
 
PEQ is tough with Macs.
Ahh I see, I use peq through Roon on my iMac/iPad/iPhone,

Perhaps check out the filo dongles, bit of a price jump though
 
A big thank you to Amir for the review. :D

The DS2 is one of our products as we make our entry into the high-performance DAC market. The DAC market is filled with many outstanding companies that everyone is familiar with. We will humbly learn from these companies as we continue to grow, and we hope to follow in their footsteps by bringing Fosi Audio’s unique touch to DACs for audiophiles worldwide. In addition to portable DACs, we’ll soon be introducing a desktop DAC as well.:cool:

To show our appreciation for the support from ASR members, we’re offering a special discount code for the DS2. You can use this code on our website to get 20% off your DS2 purchase!;)
ASRDS220

link: https://fosiaudio.com/products/fosi-audio-ds2-2024-dac-headphone-amplifier
Order placed!
 
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