Fosi Audio SK02 DAC & HP Amp Review

[Bicep]

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.

Yeah as a low income student I do need to "haggle over the last dime" if I want to get the best value per dollar quality wise.

 

[kemmler3D]

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 think that's pretty strong criticism for an opinion on design that mostly amounts to a matter of taste.

For example, take the $10K Bricasti DAC reviewed recently that Amir liked the look of. I think it looks like cheap '90s 3rd rate studio gear. What I'm here for is mostly the measurements, the opinions I will take or leave as it suits me...

 

[MacClintock]

Yeah as a low income student I do need to "haggle over the last dime" if I want to get the best value per dollar quality wise.

Ok, but still, buying cheap is buying twice, as the saying goes. When you are based in the US, I would recommend to save one month more and get the Atom Amp and DAC 2. These are well measuring, nicely designed and have excellent customer's service, as I hear. What advantage lies in a USB-powered device that has to be used on a desk anyways?

 

[amirm]

What is the use case?

Small, light, plug it in and get far more power than you get out of laptop or a dongle. Yet, it has excellent volume control and displays. Even for desktop use the fact that it doesn't need an AC adapter is a plus.

For that, you do give up some performance. Pay 2X more and you will indeed get more.

 

[MacClintock]

Small, light, plug it in and get far more power than you get out of laptop or a dongle. Yet, it has excellent volume control and displays. Even for desktop use the fact that it doesn't need an AC adapter is a plus.

I still don't manage to convince myself that the USB power is an advantage. If I can power my laptop I power it with, I can also power a DAC/amp. And with that size it is definitely not meant to be carried around, so the comparision with a dongle is not appropriate.

For that, you do give up some performance. Pay 2X more and you will indeed get more.

It is always important to know what is the base value, yes it is 2x or 100% more expensive than the DX3Pro+ or the Atom 2 combo, but it is just $100. Like you used to say, 1-2 times eating out with the family or 2-3 times fastfood.

 

[kemmler3D]

I still don't manage to convince myself that the USB power is an advantage.

Fewer cords is fewer cords...

 

[NeoZs99]

Nice. I was about to purchase the previous version. It seems it has lost the Bass and Treble knobs, but as long it measures better overall..

 

[DLS79]

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...

Typical!

 

[Doodski]

Typical!

LoL... It is a USD $99 device. It's good value for the money. I see the imperfections too although I don't expect perfection for $99 plus and it delivers so much for the price. So I think I agree with you.

 

[MacClintock]

Fewer cords is fewer cords...

Ok , I don’t need a power cable. But this also has as a consequence that I cannot use it as a standalone device, it must be fed by my laptop. This is a crucial drawback. If I just want to stream from my cellphone, what do I do? Sucking out the power from my phone (if even possible) ?

 

[Mikig]

This is a crucial drawback. If I just want to stream from my cellphone, what do I do? Sucking out the power from my phone (if even possible) ?

I'm using this Y cable for a USB device. On one side I have power, I use a very normal 5V power bank and on the other the phone.

 

[kemmler3D]

But this also has as a consequence that I cannot use it as a standalone device, it must be fed by my laptop. This is a crucial drawback. If I just want to stream from my cellphone, what do I do? Sucking out the power from my phone (if even possible) ?

It depends on the specific design and whether it will run without a USB data connection at all, but there are plenty of USB power adapters and even battery packs if you really wanted to use it on the go. Some phones will indeed power devices like this, too.

For low voltage / wattage devices USB power is becoming common even when it's not used for data. For example my GoPro uses a USB-powered battery charger, but it doesn't do anything with the USB except power.

Just look at USB as just another small DC power connector and you may feel much better about the whole thing.

 

[pseudoid]

Thank you for the review and thank you for the bonus 'listening' test… especially since I had read some false complaints (elsewhere) that ASR is all about numbers and nothing but numbers.

Fosi Audio SK02 Headphone Amplifier Measurements
We have surprising amount of power for a USB powered device:

I am wondering what the USB-C (5V) power input requirements are for supplied current? FOSI specifications (post#2) lacks this 'number'.
I am fully OCD about visible cables and SK02 DAC makes it almost impossible to hide the connections it requires (less HP cable).

Pitchin' for some free chit are we? Haha.

I had previously suggested to give-away such manufacturer-offered DUTs to a (random?) ASR member … still would like to hear your feelings about this suggestion.
[imo >> @Doodski deserves this DUT.]

 

[Doodski]

I had previously suggested to give-away such manufacturer-offered DUTs to a (random?) ASR member … still would like to hear your feelings about this suggestion.
[imo >> @Doodski deserves this DUT.]

Chuckle, chuckle... I have everything I need audio wise @ this time...gg* Give it to somebody that's just starting out, poor and maybe a student etc.

 

[pseudoid]

Chuckle, chuckle... I have everything I need audio wise @ this time...gg* Give it to somebody that's just starting out, poor and maybe a student etc.

Okay then, we can both agree that @Bicep deserves it more:

Yeah as a low income student I do need to "haggle over the last dime" if I want to get the best value per dollar quality wise.

 

[jhaider]

Like the design but the functionality is several years obsolete.

Something like this but with software licensed from Qudelix for modern functionality would be a useful addition to the marketplace. Someone at some point needs to fill the giant lacuna between the two worthwhile products in the headphone DAC-amp space - Qudelix 5K and RME ADI-2.

 

[amirm]

I am wondering what the USB-C (5V) power input requirements are for supplied current?

From memory, standard 2.0 spec for USB is 0.5 amps at 5 volts. This is 2.5 watts and should be enough to power SK02. So I don't think it needs anything special. I powered it from the hub in my monitor which is what I always use for testing.

 

[DLS79]

From memory, standard 2.0 spec for USB is 0.5 amps at 5 volts.

You are correct, that is the maximum allowed under the USB 2.0 specification.

 

[hex168]

What would be the effect of the 4 ohm output impedance on HE400SE headphones (25 ohm impedance, very low but also entirely flat)?

 

[Bruce Morgen]

Nice. I was about to purchase the previous version. It seems it has lost the Bass and Treble knobs, but as long it measures better overall..

It's an entirely different device -- the SK01 is a preamp/EQ/headphone amp box (no DAC) that's battery powered (with only charging via its USB C receptacle), the SK02 is a DAC/headphone amp (no EQ) box that's powered via USB. The form factor is pretty much all the two devices have in common.