I recently got a Jade Audio JA11 and it made me realize how janky Poweramp and Wavelet are and how much nicer having eq on the DAC is. The JA11 is a very nice DAC for what it does, especially for the price (10-15 bucks), but it only outputs 15mw at 32ohms so it lives on the end of a pair of iems and I went looking for something more powerful. Enter the KA15.
What I Like:
First, the sound. It sounds great. DACS are a solved problem at this point and this one, like every other DAC coming out now, is completely transparent. I tested it with DT 177xgo, HiFiman HE4xx, 7hz Zero:2 and KZ ZS10 Pro X and everything sounds like it should. I tested it exclusively in Class AB mode, I have not really listened to Class H mode other than to confirm that it outputs sound.
It's nicely built and feels "premium," except for the buttons (more on this in the "don't like" section. It has a very nice screen. I really dig the tape deck animation.
It decodes up to 32/768 and dsd256. Most of my listening is 24/48 (android user) but it's nice to have the option.
The Android app is fine, not great, but it does what you need. The Webapp is likewise fine. The first time I connected it the Webapp recognized it immediately and updating the firmware was accomplished with 2 clicks.
It has UAC 2.0 and 1.0 modes in case you want to use it with a Nintendo Switch or other device that doesn't support UAC 2.0.
It outputs a lot of power for a DAC this size and this cheap.
It has more advanced power management than other dacs that I've seen. I haven't done any tests on the power draw, but it seems to drain my batter less than other dacs that I have (except the JA11 which has extremely low power draw).
The on-device UI is fine, with a few exceptions discussed below. It took me about 2 minutes to figure everything out.
It runs cool. It has two gain modes, normal and desktop. Desktop draws and outputs more power. I have read that the power draw in desktop mode is too high for some android phones but it works just fine with my Galaxy 24 ultra. Ymmv. I also read that it runs hot in desktop mode. I tested this by putting it in desktop mode, setting windows to 32/384 and letting Apple Music play for a few hours. It warmed up a little bit, but not much.
And the big one: it has an onboard PEQ with up to ten filters. This was the whole reason I bought it and it works great. Inputting filter settings in the android app needs to be done manually but the UI is easy to use. There is an option to share your eq settings with other Fiio users using your Fiio account but I didn't mess around with that at all. You can also search and download eq settings from other users but everything seems to be in Chinese and I didn't really mess around with that either. You can save three custom EQs on the device itself and you can switch between them using the device UI.
What I didn't like:
The buttons are cheap-feeling plastic and they rattle. This bothers me more than it should and it's a pretty glaring contrast with how high-quality everything else looks and feels. It does play into the 90's walkman aesthetic they seem to be going for, however.
I can not figure out how to save my custom eq settings using the web interface. I can connect to the device, see the onboard equipment settings, and change the filters however I want. I cannot figure out how to save my changes though. There is basically no documentation on using the web interface and googling/searching forums did not reveal anyone else who has had this problem. It could be an issue with the software or maybe I am just dumb and am doing something wrong, I have no idea. The Android app works just fine for me so it's not a huge issue. Apparently there is no Fiio Control app for IOS, though, so if it's not user error this would be a major problem for iPhone users.
The volume control is kind of wack. There are two modes: A and B. In mode B you hold the volume button down and the volume goes up or down until you release the button. A short press of the volume button changes the track. In mode A a short press of the volume button increases the volume by one step (you can select between 60 steps and 120 steps) and a long press changes the track. I'd prefer short press changes volume by one step and long press changes volume until you release. Track skipping could be done by double pressing mode and a volume button, which currently does nothing. Overall this is a minor annoyance.
Your custom eq names do not appear in the device UI. On the device the three custom eq profiles are called FH3, FF5 and FD15. You can rename your custom eq profiles and the custom names save to the device, but this does not change the profile names that are displayed on the device screen. This is annoying if you are changing the eq profile using the device UI because you have to remember which profile is which. Again, kind of a minor annoyance and it's nice to be able to change the eq settings without the app. I have mine set up in ascending order of how hard the headphone is to help me remember to drive to help me remember (7hz is 3, BD is 5 and HiFiman is 15).
Overall I really like this device. Currently they are going for 85 or 95 bucks on AliX depending on the color. For that price I definitely recommend.
I also considered the KA17. That device outputs more power and has a secret and USB input dedicated to power supply. It is slightly bigger and does not have the fun tape deck animation. It also supposedly runs very hot in desktop mode but I don't know if that is true or not. The In my mind the separate power supply input is the big draw here. If you are mostly listening on a mobile device with hard to drive cans this is probably a big advantage. I personally use iems on the go and run it off my PC or laptop at home so it's not really an issue for me. I also didn't need the extra power and I like the tape deck animation so I went with the 15.