I have got my device. A modest, neat device.
The impression right out of the box is that this device is at least much better than the Fiio K9 Pro and Singxer SA-1 bundle.
Only Kennerton Thekk is at hand now - but it sounds very good with this source.
Precisely, distinctly, harmoniously. With a good scene.
I am very glad that I bought a Serenade
The difference in sound compared to the K9 Pro + Singxer SA-1 bundle is audible even on small (office) iLoud Micro Monitor speakers - noticeably better resolution, deeper and more precise bass, and everything related to vocals is just fine.
The treble is quite neat. Not to say that they are muted, but slightly "tidied up".
The controls are simple and intuitive.
Of the minuses, low-resistance IEMs (Snowy A7, Shanling me800) frankly hiss with this device.
That's where the Ifi IEMatch adapter came in handy, which is fine.
Especially on the bass - I have never heard such basses from my Shanling me800.
Strangely enough, there is not much heating noticeable.
30 minutes of use - the case is slightly warm.
It was written that Serenade is more suitable for dynamic headphones than for gliders, but Kennerton Thekk planar headphones sound very good on Serenade.
On the Singxer SDA6 + Aune S17 Pro bundle, they sounded pretty flawed - flat and not very interesting.
And even more so for bundle of Fiio K9 Pro and Singxer SA-1.
And with a Serenade, it is quite complete.
I thought about replacing them with something - but no, they will still serve very well.