The M11+ has a ‘lot of’ “niggly things” a firmware (or three) may be required to sort out.
Fairly high up on my ‘pressing issues list’ is the “DSD conversion” output- seems to do ‘on the fly’ DSD CONVERSION out over the analogues 3.5mm/4.4mm, either amplified or ‘line out’ (makes sense); AND it will pass out via the COAX digital output. (all good, so far)
DSD conversion feature DOES NOT OUTPUT via the USB output.
This is fairly easy to test, as DSD tracks will output (as DSD) via the USB output, but DSD Conversion passes as PCM... (and not necessarily as DSD being ‘handled’ as PCM).
The only reason i raise this point is that no doubt the M15/M17 share this Operating System build, with tweaks as necessary (if any), and this might catch out some users.... (many more users ultimately to be found in the M15/M17 product branches if only due to the M11(+) being a ‘Limited’ run)
On a massive plus note; the DSD conversion is (really) quite good.
On the ‘den setup’ (home hifi) it is easy to tell apart the two playbacks (straight vs ‘converted to DSD’). Ten for ten I chose the DSD version due to (better) nuanced playback and ‘smooth’ air spaces; it sounded the more natural /authentic. Across four music genres; easily Blind A/B’d.
Usually DSD conversion equals me switching back and forth A LOT and the differences, typically subtle, get discerned over time; but with the FiiO it was evident, when using the included AKM4497s, the improvement the DSD conversion process brought. (all test tracks being redbook 16bit 44khz)
One of the main reasons I bought the M11+ was to be a transport, and knowing the DSD convert (on the fly) was a feature FiiO offered (and that it might make the player run warm), I even bought the ‘cooling case’ specifically for this purpose.
DSD convert does run the battery down faster, about equal to having an iFi Purifier on the USB cable (requires a little power).. It isn’t a heavy hitter on the battery like I was afraid it would be (the new DSD convert code on top of the newer ‘660’ processor is a dream come true).
It is a good enough feature that I use the player, like right now, feeding ‘line out’ from the balanced 4.4mm into the home hifi rig...
I’d put the DAC capability of the player, a step above home DACs from the last half decade, and right up their with some of the best.. (down two steps from a Denafrips, down a half step from a Chord Hugo/iFi Diablo etc)
I never expected the M11+ to ‘cut it’ so well..
A large part of the M11s success is it being ‘SUCH A BRILLIANT’ transport; and I am not sure how FiiO have engineered it; but the unit exhibits a low bass note improvement so solid that the home subs needed downscaling, and the extra bass is definitely in the digital read; it gets passed onto all down stream sources irrelevant the transport method (bluetooth/USB/COAX/line out etc). Vastly improves a few genres and helps perfect a range of recordings.
....with DSD (conversion) it is (sometimes)‘even better’..
<smiles>