I compared the sound quality of the F28 ito the eversolo DMP A6 connected to the topping PA5 ii with KEF LS50 speakers. While connected to the balanced input, the DMP 6 has a clearer and more effortless sound compared to the F28. Despite this, the F28 still produces a beautiful sound.
The device is well constructed and its main advantage is that it can be controlled remotely via Bluetooth using the HyBi app.
It can also use a 512 GB SD card, making it stand out from many other players in the price range.
It operates on a simple operating system that is similar to the one of SMSL DP5. However, unlike the DP5, it allows you to adjust the filter settings (although it doesn't seem to make a difference) and has an EQ. The internal storage capacity allows for a maximum of 20,000 songs, whereas the SMSL DP5 can hold 30,000 songs and the eversolo can handle much more.
Even if songs have not been added to the library, you can still find them in their folder, also using the HiBy APP. This works an the internal SD card or an attached USB SSD.
The operating system is very simple and the screen is not really hi-res. The navigation between screens is mainly done by swiping left and right, although this can be glitchy at times. The HiBy app (on a smartphone) serves as a main control interface.
The golden knob on the device functions only as a volume control. When just touched a volume control window pops up with a slider on the screen allowing for instant adjustments. However, the sensitivity of the volume slider can lead to accidental changes in volume which I find a huge oversight of the developers.
One of the main menu options is "Scan Music," which rebuilds the database without confirmation. Canceling the scan will only show artists/albums that have been added, all other songs are removed from te list of albums/artists. Despite this, users can still play songs from the folder structure and add them to playlists. Playlists are separate from the database but can also be managed in the HiBy app. Surprisingly this also works when the F28 is already connected to a bluetooth speaker (activate the HyBi link after connection to the speaker). The sound quality over bluetooth is excellent after you have activated aptX in the settings.
Because of the inconsistent touch navigation, I do not suggest using this as a mobile player at the moment with Firmware 2.1. However, with some improvements to the user interface, it has the potential to be an ideal device. By the way, it also plays music when the USB charger is plugged in.
It appears to be a great choice for stationary purposes given the price. Unfortunately the UI glitches and the the volume knob are really a nuisance.