Files off pitch? Can’t figure it out.

I’ve been discussing this on headfi, but wanted to see what you guys might be able to add over here.  After purchasing a SONY zx-300 DAP, and returning it for a WM1A signature series DAP, I’m noticing a problem that I’m hoping can be attributed to my computer.  I’m really grasping at straws here but- here goes. 

What I’m noticing, is that both of these SONY players seem to play the tracks at a slightly higher pitch, nothing drastic, but totally noticeable to my ears, and it’s distracting. A casual listener may not notice this, especially if they aren’t familiar with the song. However, if you’ve heard a song tens of thousands of times over your lifetime, you get the notes and key of the song burned into your brain. All my other devices, which are loaded with the same files, mind you, all concur more or less, with one another- and sound like they should. If there is a slight difference in pitch, it’s negligible and small enough for the brain to gloss over.   It’s not until I got the Sony’s where my eyebrows raised when listening. For example middle C is not rendered as middle C, but a slightly higher key. It can make the song sound foreign because your brain is singing along and the then the SONY plays the song a little too high, similar to a turntable’s servo not locked in at 33 and 1/3 but more like 34 and 1/3. Now I can understand, that there may be some slight variations from machine to machine, as nothing is perfect, but the discrepancy with the Sony’s has been more than negligible. Clock issue? Firmware issue?  

It’s just strange, because nobody on headfi can replicate what I’m hearing, and frankly, I’m surprised nobody has noticed it, especially since many of them have seasoned ears.....reviewers etc. I doubt SONY would knowingly release a product that is off in pitch.  

maybe it has something to do with my MacBook, which I switched to high Sierra right before buying these DAPs but I haven’t nailed it. It isn’t a sampling error, as that would make it unlistenable, like chipmunks. I would be surprised if something is happening to the files during the transfer over to the player, but then I would expect the pitch variance to show on my other devices. I know this sounds odd, but it is definitely not imagined and I can double blind test this all day long and pick out the SONY. It’s just such a disappoint for an otherwise splendid machine. Anyone ever experience pitch differences in their digital gear like I’m describing?  Not major pitch discrepancies,  but slight,  annoying discrepancies that are just noticeable enough to take away the pleasure of listening?   Sorry for the long post, just trying to be thorough.