Fosi Audio SK02 DAC & HP Amp Review

[restorer-john]

This is as ideal of a design as one can imagine for a compact dac and headphone amplifier.

You cannot be serious! "ideal of a design" for what? It's an absolute horror-show of design and you know it.

Nothing is aligned to anything. It's hilarious to look at. I'd be ashamed to have something like that on my desk or in my house- it makes me laugh actually. The TOSLINK connector is sideways (you do know how the connector is designed don't you?). The input panel is a disaster. WTF is PO? and the "BAL" and "PO" are offset.

Stop giving these people a free ride because they send you chit to test. It's destroying your credibility. One small step away from Andrew Robinson...

 

[MacClintock]

Nice little device that measures ok, but why not spending just a little more to get more power and otherwise almost SOTA, like for the Topping DX3Pro+ or the Sabaj A10D or the latest JDS Atom stack?

 

[Doodski]

Pitchin' for some free chit are we? Haha.

Hehehe.

 

[burkm]

Just wondering, why the max balanced output as tested by @amirm is only half of what Fosi Audio claimes for the SK02 ?

 

[Bicep]

Nice little device that measures ok, but why not spending just a little more to get more power and otherwise almost SOTA, like for the Topping DX3Pro+ or the Sabaj A10D or the latest JDS Atom stack?

The difference in price is quite substantial with 2-3x the cost. I'd rather spend $100-200 extra on headphones if the devices work similar enough.

 

[mc.god]

Nice little device that measures ok, but why not spending just a little more to get more power and otherwise almost SOTA, like for the Topping DX3Pro+ or the Sabaj A10D or the latest JDS Atom stack?

They are in different category since you mentioned all AC powered devices while SK-02 is usb powered, so output power can't obviously be comparable, and all priced about double, that I don't consider "a little more" in relative terms.
I see SK-02 as a competitor of Topping DX-1 and SMSL D12, both usb powered and similarly priced. Both show better sinad and jitter but much less power and doesn't have optical input, D12 having basic BT, in the end each having it's collocation and sense depending on your needs.

 

[Walter]

@amirm could you please post the 50mV sound to noise ratio?

 

[Walter]

You cannot be serious! "ideal of a design" for what? It's an absolute horror-show of design and you know it.

Nothing is aligned to anything. It's hilarious to look at. I'd be ashamed to have something like that on my desk or in my house- it makes me laugh actually. The TOSLINK connector is sideways (you do know how the connector is designed don't you?). The input panel is a disaster. WTF is PO? and the "BAL" and "PO" are offset.

Stop giving these people a free ride because they send you chit to test. It's destroying your credibility. One small step away from Andrew Robinson...

I am guessing that aligning the inputs and and outputs would have required the unit to be slightly larger, but that is just a guess. if not, or if we are talking less than 1cm or something, then I certainly agree that it should have been done. As someone with very mild OCD, this would irritate me to look at, but it would not be a deal breaker. It would definitely make the unit appear to be of higher quality.

 

[Walter]

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

I'm thinking the same thing! (But my desk is a converted folding table, so I'd only be cutting plywood and some laminate. I'd never do it to a quality desk. Anything above Ikea level, no way.)

 

[polmuaddib]

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).

Thanks for taking the time to explain, but I am afraid I still don't get it.
Isn't Fosi Sk02 48 Hz sample rate distortion over 0.1 % around 7 KHz? While Bricasti 48 Hz distortion is 0.003 % around the same 7 Khz. Both graphs show 20 to 20000 Hz.
And ok, while 192 KHz (You wrote 92 KHz, and I assumed you just misspelled) performance of Fosi is better then Bricasti, by a small margin, under 500 Hz, but it is still worse over 1000 Hz.

But I just used Bricasti as an example, because the review is recent. My point is that You showed, in your countless measurements that there is absolutely no correlation between price and performance, or simply put a cheapest DAC can outperform the most expensive DAC.
And thanks to that, we can now choose to pay more or less for equipment, fully aware of it's measured performance.

And if Bricasti and Fossi had exactly the same performance, they should be rated the same, absolutely not considering the price. Why Bricasti is insanely overpriced is another matter.

 

[JRG123]

Finally! Someone thought about this! I mean, is it that hard to implement something so basic yet essential?

 

[amirm]

Thanks for taking the time to explain, but I am afraid I still don't get it.
Isn't Fosi Sk02 48 Hz sample rate distortion over 0.1 % around 7 KHz? While Bricasti 48 Hz distortion is 0.003 % around the same 7 Khz. Both graphs show 20 to 20000 Hz.
And ok, while 192 KHz (You wrote 92 KHz, and I assumed you just misspelled) performance of Fosi is better then Bricasti, by a small margin, under 500 Hz, but it is still worse over 1000 Hz.

That is what I explained in my post. The reason 48 kHz has skyrocketing curve is because of ultrasonic noise due to the filter choice in SK02. Not because of in-band distortion which is the issue with Bricasti. The left side of the graph takes that away and shows the audible band distortion is lower in SK02 than Bricasti. "92" by the way should have said 96 kHz. I was using Toslink which won't go higher. If you are using USB, and upsample to 192 kHz, the whole curve would flatten out much better.

 

[amirm]

You cannot be serious! "ideal of a design" for what? It's an absolute horror-show of design and you know it.

The "design" is what you see on top. The back side is not visible to you. And the front doesn't bother me, nor is that very visible. On top, it blows away countless other products in looks and usability.

 

[Robbo99999]

It's all OK for this product, I voted it Fine. Balanced & price seem amazing, but the slightly less than perfect measurements combined with what I view as a bit of an unusual form factor somewhere between a desktop product and a dongle makes it a bit less attractive & confused. I'd rather use a dongle for mobile use, and then something solid for desktop, and I'd probably choose something with slightly better measurements for desktop (just because you can for ultimate surety of transparency), and I'd be willing to pay just a bit more for that usage scenario which widens the competition to better measuring devices. It remains though that Balanced DAC/Headphone Amp for $99 is exceedingly good value!

 

[Kevinfc]

If only I had an interest in being tethered into a wired headphone….

 

[Bruce Morgen]

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

Designing in a supplanted IC is risky unless the manufacturer has committed to continued availability.

 

[Bruce Morgen]

The SK01 (which I own, FWIW) and the SK02 may share a basic -- and yes, somewhat odd -- form factor, but if they're intended to be used together I find it strange that both devices have/are headphone amps. So, if you need the tone/loudness feature, you'd need to use the SK01's headphone amp, which sort of demotes the SK02 into what amounts to a good $100 USD DAC device if/when the two are used together.

 

[Daviede]

Thanks for taking the time to explain, but I am afraid I still don't get it.
Isn't Fosi Sk02 48 Hz sample rate distortion over 0.1 % around 7 KHz? While Bricasti 48 Hz distortion is 0.003 % around the same 7 Khz. Both graphs show 20 to 20000 Hz.
And ok, while 192 KHz (You wrote 92 KHz, and I assumed you just misspelled) performance of Fosi is better then Bricasti, by a small margin, under 500 Hz, but it is still worse over 1000 Hz.

But I just used Bricasti as an example, because the review is recent. My point is that You showed, in your countless measurements that there is absolutely no correlation between price and performance, or simply put a cheapest DAC can outperform the most expensive DAC.
And thanks to that, we can now choose to pay more or less for equipment, fully aware of it's measured performance.

And if Bricasti and Fossi had exactly the same performance, they should be rated the same, absolutely not considering the price. Why Bricasti is insanely overpriced is another matter.

I think ratings need to consider comprehensive factors such as product performance, price, service, and many other aspects. Is it really meaningful to get the same score for something worth $100 and $10000.

 

[MacClintock]

They are in different category since you mentioned all AC powered devices while SK-02 is usb powered, so output power can't obviously be comparable, and all priced about double, that I don't consider "a little more" in relative terms.
I see SK-02 as a competitor of Topping DX-1 and SMSL D12, both usb powered and similarly priced. Both show better sinad and jitter but much less power and doesn't have optical input, D12 having basic BT, in the end each having it's collocation and sense depending on your needs.

Ok, but I don't get it. What is the use case? To use it in your office besides your laptop, I suppose. So you will have a plug. What do I benefit from using an USB-driven device? It is too large to use it on the go, so I really don't see what it serves for. And honestly, if you pay $100 for a mediocre measuring DAC/headphone amp combo with little power or $200 for an almost SOTA one with power for 95% of all headphones around, this is a no-brainer.

 

[MacClintock]

The difference in price is quite substantial with 2-3x the cost. I'd rather spend $100-200 extra on headphones if the devices work similar enough.

ASR made SOTA hifi gear very much attainable. But do you really have to haggle over the last dime? Come on, the Topping DX3Pro+ costs $200 and is better than many $5000 devices 5-10 years ago.