Fosi Audio DS2 Portable DAC & Amp Review

[jasonhanjk]

Recently this post made me doubt the honesty of the DAC chip from CS:View attachment 392965

Isn't it a coincidence that the measurements were taken with a 600 Ohm load in this review?

I went ahead and looked at the CS datasheet on this, and @Vamp898 was right. Given the manipulations found with CS's Dynamic Range results, I think they are indeed targeting certain measurement scenarios to show off, but the actual performance is much lower. A kind of CS "Dieselgate" of the DAC world.

CS43131 perform worse in single ended mode (or un-balance). Its balance is better than its unbalance.
Here is wolfL7 measurements: https://www.l7audiolab.com/f/tanchjim-space/

In 16 ohm load measurements:
CS43131 balance best result is 0.0007X%, taken from l7 website.
AK4377 Single Ended best result is 0.0004X%, base on my measurement.

 

[Turambar]

I use an Android phone running USB Audio Player Pro, and the LED color is changing as per the manual specs.

 

[Trasam Audio]

I dont care how does the LED color change.

I am curious why do the colors of LED lights attract your attention, can someone really remember the colors at different sample rates?

And also I dont pay attention to the LED colors when I am listening music, and it can not affect dound quality.

 

[multiformous]

Mine arrived and sounds great, however one issue, according to the manual LED light (should) change color with different sample rate, mine stays RED whatever files it's fed, or is this an android phone problem?, i'm using Poweramp as my software player of choice.

Sounds very much like an Android-related problem, as it will resample to 48kHz unless you use an app that can take control of the dongle directly with 'exclusive mode'/'bit perfect' to avoid resampling.

 

[mrmoizy]

A big thank you to Amir for the review.

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.

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

Thanks! Used the code today, really excited to try it out! Great work

 

[danadam]

Mine arrived and sounds great, however one issue, according to the manual LED light (should) change color with different sample rate, mine stays RED whatever files it's fed

Which manual? This one:

Fosi Audio Product User Instruction DS2

Design by GemPages

fosiaudio.com

says that the LED only indicates which combination of PCM/DSD and Low/High mode is used.

 

[danadam]

Thanks Amir. Any comment on the question regarding maximizing dynamic range and whether it's best practice to have the source (phone) on full volume and use the dongle for volume control?

When watching youtube on my laptop through Tanchjim Space with Truthear Zero Blue, the comfortable volume level for me is -45 dB. Measured with E1DA ADCiso, I don't see any difference between software and hardware volume:

 

[capt.s]

Thanks for the measurements! Just to clarify I'm understanding correctly:
Top Graph - DAC/Dongle on max volume and laptop dialed down to -45dB
Bottom Graph - Laptop on max volume and DAC/Dongle dialed down to -45dB
Correct?

 

[GD Fan]

Unit already arrived in the mail today. Nicely packaged, and the DS2 feels very sturdy and well made. Fit of the connectors feel precise. Gets a little warm during use but not by much.

So far battery draw from my Samsung S23 seems fairly low.

Very happy with the purchase.

Edit: silly typo

 

[mc.god]

When watching youtube on my laptop through Tanchjim Space with Truthear Zero Blue, the comfortable volume level for me is -45 dB. Measured with E1DA ADCiso, I don't see any difference between software and hardware volume:

View attachment 394630
View attachment 394631

Just for a comparison: is OS system volume normally working or do you have to use application software volume? I'm asking because Sonata BHD doesn't enable OS system volume (both in windows and linux), it is always maxed out no matter how you move the slider, and only controls you have are the physical buttons on the unit or software volume of the app playing sound, but I don't know if all dongles with volume buttons behave like this.

 

[danadam]

Thanks for the measurements! Just to clarify I'm understanding correctly:
Top Graph - DAC/Dongle on max volume and laptop dialed down to -45dB
Bottom Graph - Laptop on max volume and DAC/Dongle dialed down to -45dB
Correct?

Yes.

is OS system volume normally working or do you have to use application software volume?

Yes, OS volume is working. I used alsamixer.

 

[mc.god]

Yes, OS volume is working. I used alsamixer.

Thank you, so different implementation of the Savitech bridge.
Just to end the comparison, in alsamixer i have this as default:

that is synchronized with graphical OS volume slider (pipewire) and have no effect until you get down to around 10/100, then it start to attenuate at very few big steps until muting at 0/100.

If i press F6 i can select directly the dongle:

And here the slider has absolutely no effect until suddenly muting a 0/100.

At first i was puzzled, since accustomed to previous dongles without volume buttons and only controls at OS level, but honestly now I like more this way, since I know that i have to rely solely on physical buttons and can't make mistake.

 

[Bicep]

Thank you, so different implementation of the Savitech bridge.
Just to end the comparison, in alsamixer i have this as default:

View attachment 394670

that is synchronized with graphical OS volume slider (pipewire) and have no effect until you get down to around 10/100, then it start to attenuate at very few big steps until muting at 0/100.

If i press F6 i can select directly the dongle:

View attachment 394671

And here the slider has absolutely no effect until suddenly muting a 0/100.

At first i was puzzled, since accustomed to previous dongles without volume buttons and only controls at OS level, but honestly now I like more this way, since I know that i have to rely solely on physical buttons and can't make mistake.

This seems like a hassle if one swaps between using it for headphones and an amp though. Accidental blasting 100% volume into IEMs is no fun if one doesnt want to correct volume through the dac itself.

 

[AdrianusG]

I use an Android phone running USB Audio Player Pro, and the LED color is changing as per the manual specs.

Okay, i see.
So it is an android problem, not a big deal, i'll keep using Poweramp anyways as it gives me a lot great settings to play with, and no, the LED's color doesn't affect SQ

 

[mc.god]

This seems like a hassle if one swaps between using it for headphones and an amp though. Accidental blasting 100% volume into IEMs is no fun if one doesnt want to correct volume through the dac itself.

Yes, I agree it can be problematic in some use cases, that's why i wanted to check if DS2 behave the same or not.

 

[renaudrenaud]

Working with PopOs.

 

[Eddie]

It's SA9312, made by Savitech.

View attachment 393365

Where did you get the image from? I checked Fosi's website https://fosiaudio.com/products/fosi-audio-ds2-2024-dac-headphone-amplifier but did not find any information about the USB bridge.
I also checked Savitech's website https://www.savitech.co/usb-products and the only USB bridges they offer are SA9123L Pro and SA9302L. Is SA9312 a discontinued product?

 

[Eddie]

Picked up my DS2 today. Haven't used it much, but initial impressions are quite positive. Setup was plug-and-play, and all sample rates from 44100–384000 fs work without issues. A sample change rate results in a fade-out + fade-in — no clicks or pops. Also tried DSD64 with foobar2000 in exclusive mode, works flawlessly. The sound is clear and neutral, and the DS2 drives my headphones without issue.

Edit: found one issue. When skipping through a track in exclusive mode, there is a discontinuity — it fades out and in, just like a sample rate change. This is true even when using SoundKeeper. Normal shared mode is fine. Will perform more tests tomorrow.

A question about that issue:
By "exclusive mode" do you mean Windows 10's WASAPI exclusive mode? If so, does it also fade in if you start playback? And does it fade out if you stop playback? To me that would be just as ugly as clicks and pops. Is this only with foobar2000 or with other software, too?

 

[GeekyBastard]

Where did you get the image from? I checked Fosi's website https://fosiaudio.com/products/fosi-audio-ds2-2024-dac-headphone-amplifier but did not find any information about the USB bridge.
I also checked Savitech's website https://www.savitech.co/usb-products and the only USB bridges they offer are SA9123L Pro and SA9302L. Is SA9312 a discontinued product?

Fosi Audio's official Taobao(Tmall) Store in China.

 

[mc.god]

I also checked Savitech's website https://www.savitech.co/usb-products and the only USB bridges they offer are SA9123L Pro and SA9302L. Is SA9312 a discontinued product?

For end users trying to get clear information about savitech products can be dark hole, I never understood if the info on official site are outdated or lacking, if 9312 is discontinued or not, but at the end of the day the only thing that really matters to us is that the drivers are working with the dongle.
Info about 9312 can be found here
https://www.pawpaw.cn/media/documents/2022-12/SA9312L_V10_201709041.pdf