Fosi Audio DS2 Portable DAC & Amp Review

[jkim]

Saw a neat noise thrick that I never saw before.
This is stepped 997 Hz measurments from -5dBFS input down to -50dB input.
From loud to quiet
L + R, R inverted out, by the way.
View attachment 442936
So at -50dBFS the noise goes down.
The other way round, from quiet to loud, the noise raises gradually from -25dBFS
dBr and dBFS
View attachment 442938View attachment 442939
So its a hysteresis with the noise. If it is set by loud it will not reset from that value until less than -50dBFS is input for some (to me) unknown time.

This is a good find. It is a technique for increasing dynamic range, also used in ESS DAC chips. But Cirrus Logic's implementation seems to be different. I will also post what I measured in my JM20 Max review thread.

 

[torgeirs]

Yes, and noise going to lower volumes is dictated by the noise at the start volume. So going from let's say -20 dBFS, the noise will be lower.
Lent your exellent informative picture

 

[Krazy8]

Hello again! After some monitoring of the IEM market, I’ve settled on the Truthear Hexa. Do you think they’ll pair well with the Fosi Audio DS2?

 

[Deeluik]

Just bought the DS2 with a usb-c splitter for charging while listening. Also bought the Truthear GATE and it combines well. Also tried this with my AKG K702 also enough power to drive this one. For playing DSD on my iOS device I found I had to turn off hearing protection in iOS. Then the led went blue Thanks ASR for saving my money

 

[Blank Verse]

Hello again! After some monitoring of the IEM market, I’ve settled on the Truthear Hexa. Do you think they’ll pair well with the Fosi Audio DS2?

The DS2 is just slightly warm, but pretty neutral. It should be a good match for your Hexa. Nowadays there are no huge differences in sound signature among different DAC chips. I also have the DS1 (which has an ESS chip) and it is only slightly brighter than the DS2. Apparently ESS toned down their chip sound signatures compared to how they once used to be. My LG V20, which is almost 10 years old and has ESS DAC chips sounds somewhat brighter than the DS1. Even then, the difference is not abysmal.

 

[Blank Verse]

Just bought the DS2 with a usb-c splitter for charging while listening. Also bought the Truthear GATE and it combines well. Also tried this with my AKG K702 also enough power to drive this one. For playing DSD on my iOS device I found I had to turn off hearing protection in iOS. Then the led went blue Thanks ASR for saving my money

I have been thinking about getting one of those USB-C splitter cables, but going through the different Amazon options it is hard to decide. Which one did you get?

 

[Robbo99999]

The DS2 is just slightly warm, but pretty neutral. It should be a good match for your Hexa. Nowadays there are no huge differences in sound signature among different DAC chips. I also have the DS1 (which has an ESS chip) and it is only slightly brighter than the DS2. Apparently ESS toned down their chip sound signatures compared to how they once used to be. My LG V20, which is almost 10 years old and has ESS DAC chips sounds somewhat brighter than the DS1. Even then, the difference is not abysmal.

I'm sure you can't describe DS2 as "slightly warm", it's a transparent DAC/amp, it doesn't colour the sound at all - which is how it should be. Just saying this for the benefit of the new member you were talking to.

 

[danadam]

I'm sure you can't describe DS2 as "slightly warm", it's a transparent DAC/amp,

I only scanned the posts and until I read yours, I thought he meant the actual temperature

 

[Robbo99999]

I only scanned the posts and until I read yours, I thought he meant the actual temperature

Well at least this part of the thread hasn't been sent to the "can DACS have sound signature" thread yet!

 

[Blank Verse]

I'm sure you can't describe DS2 as "slightly warm", it's a transparent DAC/amp, it doesn't colour the sound at all - which is how it should be. Just saying this for the benefit of the new member you were talking to.

I have both the Fosi DS1 and the DS2, and they don't sound the same. To my ears, the DS2 sounds warmer. Why do you think that it is transparent? How do you actually measure transparency? In any case, the DS1 and the DS2 don't even measure the same, so both can't be transparent. Are you implying the DS2 is transparent but the DS1 isn't?

The DS2 is a nice DAC, but I find myself using the DS1 almost all of the time because it has a higher power output, and to my ears, with the IEMs and headphones I use, it sounds more neutral (less warm). It is hard to ignore what your ears are telling you. An additional annoyance of the DS2 is the audio cutouts when the audio stream is interrupted and resumes. Very annoying, though it is still a fine sounding DAC. The only thing the DS1 does worse than the DS2 is power consumption, as it is much more power hungry and it warms up (this time I am talking about temperature) quite easily.

 

[Blank Verse]

Well at least this part of the thread hasn't been sent to the "can DACS have sound signature" thread yet!

All DACs have sound signature, of course. That is what the A part of the acronym stands for.

 

[Robbo99999]

I have both the Fosi DS1 and the DS2, and they don't sound the same. To my ears, the DS2 sounds warmer. Why do you think that it is transparent? How do you actually measure transparency? In any case, the DS1 and the DS2 don't even measure the same, so both can't be transparent. Are you implying the DS2 is transparent but the DS1 isn't?

The DS2 is a nice DAC, but I find myself using the DS1 almost all of the time because it has a higher power output, and to my ears, with the IEMs and headphones I use, it sounds more neutral (less warm). It is hard to ignore what your ears are telling you. An additional annoyance of the DS2 is the audio cutouts when the audio stream is interrupted and resumes. Very annoying, though it is still a fine sounding DAC. The only thing the DS1 does worse than the DS2 is power consumption, as it is much more power hungry and it warms up (this time I am talking about temperature) quite easily.

You've been around ASR long enough to know what the arguments are. (I was replying to you mainly to give perspective to the new guy you were talking to).

 

[Blank Verse]

You've been around ASR long enough to know what the arguments are. (I was replying to you mainly to give perspective to the guy you were talking to).

But the DS2 doesn't even measure the same as the DS1, so I guess science backs me up on this one.

 

[Robbo99999]

But the DS2 doesn't even measure the same as the DS1, so I guess science backs me up on this one.

Lol, I'm stopping now, this is not the thread for this age old discussion that has been had many many many times here on ASR.

 

[Blank Verse]

Lol, I'm stopping now, this is not the thread for this age old discussion that has been had many many many times here on ASR.

I was responding to @Krazy8 based on my experience, since I own both the DS1 and the DS2 and I am familiar with their "sound signatures". The concept of transparency is fine. It is a theoretical goal for a DAC, but these devices are not perfect. Their implementations can impart a sound signature. The DS2 is definitely warmer, and that is why I think it will be a good match for the Truthear Hexa.

 

[Fdr186]

You absolutely can. Just be careful about software volume control.

Hello, I have a follow-up question. I wanted to use the DS2 as minimalisti dac to connect PC to headphone amplificar, single ended, via a Y-split 3.5 to RCA.
I was in the producer marketplace and just to err on the safe side I asked there if it could have been done. The answer was “No”. Befuddled.
Am I missing something, or is it really so @Fosi Audio, anyone?

 

[mc.god]

Hello, I have a follow-up question. I wanted to use the DS1 as minimalisti dac to connect PC to headphone amplificar, single ended, via a Y-split 3.5 to RCA.
I was in the producer marketplace and just to err on the safe side I asked there if it would have been done. The answer was “No”. Befuddled.
Am I missing something, or is it really so @Fosi Audio, anyone?

You'd better post this in the DS1 thread, anyway there is no reason why it cannot be done. When talking about 3.5 mm single ended output, any dongle can be used as a pure dac feeding an external amp with a splitter cable as you said.

 

[Fdr186]

You'd better post this in the DS1 thread, anyway there is no reason why it cannot be done. When talking about 3.5 mm single ended output, any dongle can be used as a pure dac feeding an external amp with a splitter cable as you said.

It’s the right thread, sorry, typo, corrected
Thanks for your input anyways, that was exactly my understanding before receiving that answer

 

[Noricha]

I bought one for my partner's HD599se. After comparing it with my Sabaj A10h and a Topping D10s, I saw no reason to clutter up my desk so much. So I bought a second one for myself.
I find it incredible that such good performance can be achieved in such a compact size.

 

[audiomike]

Hello I've got a question are they releasing revised Fosi DS2? Because on ali shop I found a seller with both versions named DS2-2024 and the new one DS2-2025. Does anyone have more info about this?

edit found this pic and also there is new color variant https://fosiaudio.com/pages/dac-headphone-amplifier-ds2