Review: F.Audio KS01 – Brilliant For Price

Attention! It has many hardware or firmware problems!

Disclaimer:

The F.Audio KS01 Dac was bought with my own money, I will try to be as objective as possible and being a common audio enthusiast I will use simple words in this review.

I’ve chosen to give this one a try because of its crazy low price and very little information about it.

Since I have a very restricted budget, the existence of so cheap products intrigues myself.

From my point of view Dacs sound very similar to each other, or at least they shouldn’t take away or add anything to the sound, but also this time some small differences are easily noticeable.

I’m going to compare it with cheap dongles I own with similar prices.

F.Audio KS01 Packaging:

The F.Audio KS01 comes in a decent carton package, with just the front brand and nothing else. 

Once opened inside, we find the dac embedded, below we find the accessories:

– Type C to type C cable 

– Type C to USB A cable

Quite impressed to find 2 nice braided cables but surprised to not find anything else! Manual? Warranty card? No information about manufacturer or customer service.

F.Audio KS01 Tech Specs:

• ES9038Q2M + ES9603Q Amp
• PCM 768kHz/32bit and DSD512 
• 3.5mm SE: 2Vrms – 280mw
• OLED display 
• Signal to Noise Ratio (SNR): 118db
• Distortion: 0.0015%
• Price around 35-50 USD

F.Audio KS01 First impressions:

The KS01 seems and feels quite cheap but well built with a zinc alloy frame. Actually it is really light weight and seems like an empty enclosure.

Seeing a display at this price is quite crazy! It shows the brand name on the boot, the volume level and information about the quality of the track.

The black faces are probably made of thin plastic or tempered glass that retains a lot of fingerprints.

The buttons have good pressure feedback, similar to some phones volume adjusters.

They work on Android and OSX without any issue but how they work depends on the firmware you are using and also the device which is connected. It’s a strange DAC with more firmwares than information!

F.Audio KS01 Firmwares:

Yes this F.Audio KS01 got more firmwares than information! After some searching I was able to find the folder containing the drivers and firmwares.

There are 3 versions:

• V19 (older not tested)
• V20 (160 volume levels, independent volume on OSX and Android, you can change also tracks from it with fast double click)
• V22 (with 2 different version for buttons functionality)

When it comes you will find just 128 volume levels (I suppose it is the V19 firmware).

I’ve firstly tried the V22 but it seems there are just 140 volume levels and some weird buttons function, so now I’m on the V20 that seems really better and with 160 volume steps.

Here you can find the firmwares and see what changes between them.  I forgot to tell you that the instructions are in Chinese so you’ll have to translate it.

• Update 31/03/24

New firmware came out and I updated the folder. Attention, there are several bugs with inverted channels. The most stable always seems to be the V20. Perhaps there are different batches and therefore different compatibilities with the latest firmware. I recommend you try them carefully one by one.

KS01 Firmwares Folder

F.Audio KS01 Power:

I don’t know if the tech specs of the F.Audio KS01 are right but for sure this dongle got some power!

Maybe 280mw are too much for that amp section but it still really good! For this crazy price is a monster!

Also on high volume the DAC is still cold! It also seems to consume very little battery!  Just luck or was there an optimization?

Its power is fine for that hungry beast of the KZ PR2.

Really low hiss or background noises also with super sensitive iems like Hidizs MS3.

I tested it with:

• KZ PR2 need 70% volume
• Blon Z300 in 3.5mm just less than 50% volume
• Whizzer He10 and HE01 need less than 50% volume
• Hidizs MS3 and MS5 both needs 45% volume
• Philips X2HR needs like 65% volume to shine

F.Audio KS01 Sound Signature:

I keep reading that ESS chips are warm and dark but actually both Hidizs XO and KS01 have some extra touch on the treble area.

The sound is more refined than a Cirrus and also more neutral.

The soundstage seems to be slightly wider, good layering and bass are not boosted.

This thing sounds amazing for the price and probably is really hard to find anything better. 

It is cheaper than the Jcally JM60 that doesn’t even have a screen and a removable cable!

This F.Audio KS01 price/quality ratio is insane.

Fast Comparison:

vs Jcally Jm10

Jm10 got some warmer sound and slightly improved bass. Both of them are powerful but actually the KS01 is way better. Firmware updates, 2 cables, Display and control buttons for the same price.

vs Hidizs XO 

Both are ESS equipped with that extra touch on the trebles. They’re both extremely good and also extremely different. The Hidizs XO seems slightly more detailed but the KS01 seems more natural.

vs TP20

Cirrus Logic is definitely warmer than the KS01. Here you can definitely hear the flagship chip. The KS01 emphasizes the treble slightly while the other emphasizes the bass. Also the soundstage seems better.

The TP20, however, with its balanced output has much more power and is suitable for use with even harder headphones to drive.

vs Creative SFXi

The Creative DAC probably has the same power. You can find this one at 50USD and still one of my favorite 3.5SE! More support (firmware updates + Apps). His sound is warmer than the KS01.

The KS01 is probably as good as the Creative in terms of sound quality.

Who do I recommend this DAC to?

If you are a beginner or on a budget, maybe changing/updating the firmware with Chinese instructions is not ideal, but if you are practical it could be an excellent dac from which to start this hobby.

Also If you don’t need a balanced output this could be a great option for your pockets. If you search for similar chip setup the price is way higher. The possibility to change firmware makes this suitable for more devices and customers.

Is it durable? I can’t tell you but actually I didn’t have any dead Dac in my collection. Having obsessive care for my products I’m not the most suitable subject if this DAC is durable.

3/5

Pros:

• Good Build Quality
• OLED display 
• Flagship chips
• Slightly bright sound (ESS)
• Removable cable
• Different Firmwares 
• Functional buttons for volume adjustment and play, pause and change song (depending on the firmware)
• Strong power
• Zinc alloy frame
• Super light

Cons:

• Front and back design are exactly the same
• Black plastic love fingerprints 
• No balanced output
• Seems a little bit cheap 
• Messy informations
• Really hard to find Firmwares
• Many issue reported from users (be careful)

Where to buy:

https://a.aliexpress.com/_EQE3rtv (Where I took mine)

https://a.aliexpress.com/_EGiV90P (Cheaper)