Andy, thank you for the reply and all the efforts!
I'm still about to dig some information on folder-to-folder playback support by other DAPs.
Meanwhile, there is one thing, that ails me-such a great number of OP AMPs used in the DAP. Maybe, it's because of the 13 OP AMPS in Cayin N6, which is considered an unlucky number in some cultures
I, personally think, that in the majority of cases the fewer the elements (the simpler the design) the better. There are some people, including my father, who's a process automation engineer with a rich experience and who goes in audio for a hobby, which deem the use of OP AMPs detrimental for the sound (I mean the subjective part of it, or the sound signature-the thing we all strive to adapt to our liking or to find the most personally preferable one, not the measurements). They think so because the OP AMPs generate negative feedbacks, thus suffocating the "sound". Of course, OPAMPs use is essential, even indispensable for the mobile solutions and the manufacturers base their design on their experience and tests results, still...
Surely, Cayin N6 has a unique design with so many OPAMPs, which are more than twice as many as "only" 6 OPAMPs in my ibasso DX90, but are they really necessary?
Nowadays, so many products boast dual DACs (as Hifiman HM-901, Cayin N6, ibasso DX 90, etc) and many OPAMPs. James FiiO, the FiiO manager and,obviously, a public relations man, written in the FiiO X7 (upcoming FiiO flagship DAP) thread that they are about to use
up to 7 (the final number is undecided yet) crystal oscillators (Cayin N6 has three) in X7 design
!
It seems everyone is obsessed with quantity and not the quality these days. Anyways, my post is offtop and expresses only my opinion