Nice new features, although I haven't tried them yet.
But I have one issue since firmware 1.21 (the introduction of the alphabetic search function): The Resume function doesn't work anymore. I only get it working again with firmware 1.20 or older. Does nobody else experience that? It would be less of a problem if deep sleep mode would also work with attached charger.
Sadly nobody has responded, but apparently it's an individual problem of my unit.
Some news from the
Resume front. I had the idea of reformatting the SD cards. This also in view of the fact that they haven't been formatted by the X5 II itself, but by a Windows tool called HPUSBDisk. Until firmware1.21 I didn't experience any problem from that. But I thought: who knows! So I took the cards out and began to copy the content on the computer HDD for recopying it later, after formatting. In the meantime I used an identical Samsung card with 128 GB and with the same formatting method, but different content, for slot 1 (slot 2 empty). To my surprise the Resume function was working. With one exception: In the mode «last position» it only worked when the song wasn't paused at its beginning; 1 s was sufficient to make it work.
Then I inserted two SanDisk cards (from the X5 [1]) – also with 128 GB and formatted with HPUSBDisk – with virtually identical content as the problematic ones, and they showed the same behavior; all I had to do was to avoid pausing the song at its beginning or to chose the «last song» mode. So far, so good. After the copying of the SD card intended for reformatting was finished, out of curiosity I inserted both problematic Samsung cards again. What was that?! The Resume function was working now! With said restriction. I haven't changed anything on them. And the player used the same (refreshed) database as ever. (BTW, clearing and refreshing the database were things I tried before without success).
Now I wonder what the cause of this mysterious behavior is/was. And can aynone test if your own X5 II shows the same malfunction with the song paused at its begining when set to «last position»?
Some thoughts to the new filter choice. I don't agree that the ringing of a conventional steep antialiasing («reconstruction») filter be inaudible. Since it has a frequency of 20 or 21 kHz, it may appear logical. But this filter resonance only is limited to the filter's cut-off frequency if the filter has a Q factor of ∞. Everything below will result in a spreading of the resonance around the center frequency – the lower the Q factor, the wider the spreading. At least that's my understanding.
It gets confirmed by the fact that different ringing characteristics sound different. On the Corda Symphony (DAC/amp combo) you have the choice between various low-pass filter characteristics. Two of them with virtually the same frequency response. One of them shows symmetrical ringing, the other manages to largely avoid pre-ringing, in exchange post-ringing is slightly increased. It's not even a matter of better or worse, but they do sound significantly different. (It's not night and day, but clear enough.)
So there's nothing wrong with the «slow down» filter except for the early high-frequency roll-off – which is definitely audible as such to my ears. In turn the «steep drop» filter offers more extended high-frequency response, but also a colder sounding treble (as I hear it). To my ears the «slow down» filter also offers better texturing and a more natural sound. Actually I was never a fan of «slow down» filters on earlier occasions – so I preferred the Theta Pro basic II treble to the Wadia X30 treble and the two sharper filters on the Symphony to the softer versions. But with the X5 II's headphone out and the Shure SE846 I seem to prefer it now. This although you wouldn't think the SE846 benefit from an early treble roll-off.
So thanks to FiiO for this fascinating feature!