Fosi Audio SK02 DAC & HP Amp Review

[gvl]

If headphone outputs were on the top panel I’d be tempted to cut a rectangular hole in my desk for a flush installation

 

[polmuaddib]

I've seen much better performing DACs receiving the headless panther because of the price. Can't understand why the price makes this one a great DAC. A cheap DAC I agree, but then I've seen cheaper dongle dacs performing better here.

I agree.
There is a lot of distortion rise when sampled at 48 khz, which is often output sample rate for PCs, which makes this device underpefrormer.
If we are judging on performance alone, disregarding the price, then this device can not be recommended, right?

When Amir reviewed Bricasti, which showed similar SINAD but much better THD vs frequency at 48 KHz, there was a heated discussion about how overpriced it was.

I am just saying that the price information should be for information only and not a factor that is considered in performance evaluation.

 

[daniboun]

Here a 15 % limited coupon : FASKMKT15

Fosi Audio SK02 Desktop DAC/Headphone Amp

The SK02 employs a minimalist and stylish design language. Despite its small size, it boasts mighty features. It supports DSD256 and PCM 32bit/384kHz high-resolution decoding, along with 3.5mm single-ended and 4.4mm balanced headphone outputs.

fosiaudio.com

 

[JSmith]

And here is a dedicated 15% discount promo code for all ASR members: FASKASR15

Here a 15 % limited coupon : FASKMKT15

I hear there is some kind of coupon on offer?


JSmith

 

[amirm]

When Amir reviewed Bricasti, which showed similar SINAD but much better THD vs frequency at 48 KHz, there was a heated discussion about how overpriced it was.

I was specific that for the cost, its wideband THD is too high:

The distortion there is in audible band because the Bricasti has excellent filters. The SK02's issue is ultrasonic noise. If you take that away (due to filter), then it actually beats the Bricasti!

Notice how SK02 goes below our reference in dashed line (< 500 Hz) whereas Bricasti is above ("92" kHz line).

 

[shuppatsu]

Do you get the same performance with the 3.5mm auxiliary output? Does the volume knob control volume to the aux out? Does it output concurrently with the headphone out?

 

[amirm]

I didn't test Aux out. Usually it is the same as HP out but with higher impedance (which won't make a difference in measurements).

 

[raif71]

If headphone outputs were on the top panel I’d be tempted to cut a rectangular hole in my desk for a flush installation

If you are seriously contemplating on doing that, the sk02 hp out can easily be connected to an adapter like below and its female out can jut out from the hole in your desk

 

[Jeromeof]

I didn't test Aux out. Usually it is the same as HP out but with higher impedance (which won't make a difference in measurements).

Does plugging in a headphone mute the aux output?

 

[Fosi Audio]

The AUX out is a compound port in that it supports both 3.5mm aux and optical out.

 

[PlasticDoc]

The product has a simple and effective interface that aligns with principles 4."product understandable" and 6. "honest design" of Dieter Rams' 10 principles of Good Design.

In this price range, it may have been more feasible to use a DAC such as the AKM AK4493S instead of the ESS ES9038 to control the IMD and the high frequency filtering. Alternatively, the use of an ES9039 chip would have been even better. However, considering the price point, it is understandable that cost constraints rather than technical expertise may have been the limiting factor.

The orange knob is becoming a brand image that Fosi should not ignore.

 

[Doodski]

The AUX out is a compound port in that it supports both 3.5mm aux and optical out.

I am impressed that you Fosi Audio are represented here in ASR. To have you here like this is going to pay off in time. I have 24 professional years experience in audio gear. 9 years working as a sales person selling it and 15 years as a electronic technician fixing it and I know what happens when a sales representative attends to matters personally and cares about the product. This Fosi Audio SK02 is a nice piece and you are making it nicer by being here.

 

[Mathijs Kok]

I am impressed that you Fosi Audio are represented here in ASR. To have you here like this is going to pay off in time. I have 24 professional years experience in audio gear. 9 years working as a sales person selling it and 15 years as a electronic technician fixing it and I know what happens when a sales representative attends to matters personally and cares about the product. This Fosi Audio SK02 is a nice piece and you are making it nicer by being here.

You are so right. That's the kind of behavior that makes me buy Fosi. Good hardware combined with a human touch.

 

[mc.god]

In this price range, it may have been more feasible to use a DAC such as the AKM AK4493S instead of the ESS ES9038 to control the IMD and the high frequency filtering. Alternatively, the use of an ES9039 chip would have been even better. However, considering the price point, it is understandable that cost constraints rather than technical expertise may have been the limiting factor.

Just my speculation, but could it be that with 9039 out, the 9038 is now obtainable at highly discounted price?

 

[Bicep]

Do the volume knob change the volume of the 3.5 port on the back? I'm curious how this would work with the v3. Can I leave the v3 connected at all time? Does inserting a 3.5/4.5 in the front mute the back port? Currently using an apple dongle for a dac and I'm mostly listening to the speakers or IEMs, but it seems like I get enough volume on my fidelio x2 even through the dongle.

Also, how important is the high pass filter really? Seems like most sounds generated by a source would include a bunch of ultrasonic noise. Could one use peace apo to just EQ it down to nothing?

 

[JeremyFife]

Thanks for another interesting review.
That's a cute little device that measures nicely, looks good.

One comment did catch my eye regarding the ESS hump "I put most of the blame for this on ESS for not issuing a bulletin on how to fix this, leaving every company to have to fix it themselves."
Is that fair these days? Even I have heard about the issue (I couldn't fix it, but I'd know it needed fixing). Does seem slightly remiss of Fosi not to have dealt with this better.
I don't think it detracts from actual performance, but that and a few other niggles (e.g. filters) stop this from being top rank for me.

 

[Saponetto]

Oh, damn.
Don't need it at all, but I like so much its form factor.
Thanks @amirm for getting me on the damnation path! hehe!

 

[PlasticDoc]

Just my speculation, but could it be that with 9039 out, the 9038 is now obtainable at highly discounted price?

Below are some key points that may be of interest:

The ES9038Q2M costs around 18€ and the ES9039Q2M costs around 16€ (due to the release of the ES9039Pro which costs 85€). Naturally, some manufacturers can obtain lower prices.

The ES9039Q2M is the soul of the SMSL D-6s DAC+BT (arguably the state of the art in its class of product and price range).

The AK4493S powers the SMSL SU-1 (unfortunately without a remote control) and many other designs like SMSL SANSKRIT 10Th MKIII, TOPPING E30 II LITE, etc.

The ES9038 chip and its IMD hump is old (if it were a human being it would be about 70 years old). While some manufacturers have been able to mitigate it, there is no reason (not even economic) to continue using it in devices that aspire to above-average performance.

 

[restorer-john]

I am impressed that you Fosi Audio are represented here in ASR. To have you here like this is going to pay off in time. I have 24 professional years experience in audio gear. 9 years working as a sales person selling it and 15 years as a electronic technician fixing it and I know what happens when a sales representative attends to matters personally and cares about the product. This Fosi Audio SK02 is a nice piece and you are making it nicer by being here.

Pitchin' for some free chit are we? Haha.

 

[fordiebianco]

Excellent little gadget and performance absolutely in line with price point, so voted fine. Thanks @amirm and @Fosi Audio .