The He 5xx's are only 18ohms or so, but being planars, they need a lot of wattage to make them sound as they should. In fact I've seen where people drive them with the R3, but to get to a 'listenable' level, the volume is pumped up to around 80/100. And I think you'll be getting distortion as well.

I'll do it properly and go for a full Watt (4X the output of the R3). I'm just trying to work out if to go for a desktop amp or a 'portable' like the Xduoo XD-05 Plus. I just need to find out since the Hiby has its own operating system, not Apple or Android, whether this has any effect on its operation. I doubt it, but better to know for sure. Another bonus is you can change amp boards in it to change the sound signature.

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I have the same issue. It happened suddenly without any notice. Pls inform how to fix it. More on reddit.com

I recently got myself a FiiO M3K DAP as something in addition to my previous NW-A55 from Sony. Here are my thoughts so far: Sound: It's fine and neither better nor worse than the Sony as such. The power output is approximately similar and there are no issues with the sound on suitably easy to drive headphones or earphones. The tuning differs from the Sony. The Sony is quite coloured, which results in a very smooth and pleasant sound, whereas the M3K is brighter and although I would not call it neutral, it is definitely more neutral than the Walkman. This means that they sound a bit rougher, but it also does a lot to improve the mids, so it does sound good overall. However, the Walkman has 2 options for gain, whereas I have not found the FiiO to have anything like that. Similarly, the Sony has 2 options for roll-off, which the FiiO does not have either. The M3K also does not have any of the sound effects that the Sony has outside of the EQ and the EQ is just as limited as it's on the Sony. Software: I find it to be mostly fine. People have complained about the navigation, but I like it. I prefer the form factor of controls that are separate from the main display, so that is not a part that I mind. Besides that, the navigation seems to work fine. The scrolling thing could be a bit more precise, but I'm able to use it accurately, so it's fine. As far as the I goes, I think it works well enough for the controls. However, the text and stuff is a bit too small for my liking in some menus such as the list of music. Besides that, I don't have a problem with the UI. However, what is a bit of a problem is bugs. Well, one bug in specific. The player sometimes just stops being able to turn on the screen. The side controls still work and the music continues playing, but the screen does not turn on until I restart the player. This has happened multiple times during the few days for which I have had this player. In contrast, I have owned the Sony for almost 2 years now and have not noticed a single bug in that time. It's pretty clear that the quality of the Software used on the FiiO lacks polish, although it's not a dealbreaker for me. Buttons: It has volume, power and pause/play buttons on the left side. These work fine. There is also a front surface with touch sensitive areas for navigation, skipping tracks and whatnot. These are great when looking at the device, but means skipping tracks doesn't really work when the player is in my pocket. The Sony does have more buttons that make in-pocket music navigation better. There's also no hold switch like there is on the Sony, although the front controls do not work with the screen off, so things shouldn't get pressed too easily and my experience is that it's fine in this regard. Build: Body is metal with a glass front, so it feels quite rigid. It does come with a case, but it feels pretty awful, so I prefer using the player without it. The player is quite a bit smaller than the Walkman as well, which is nice. Conclusion: It's a great player for its price point with a great form factor imo. The sound is good and I have no complaints about the build. It could benefit from more side buttons, but it's totally usable as it is. The only real issue I had is that the software on the product is quite unreliable. More on reddit.com

I have 7th gen & a Fiio M3K and personally i would go with ipod if you have a large library and m3k if its smaller. The interface on the fiio is a little slow if you you are looking for something specific and ipods are really fast. Both players sound good, Fiio probably a little better and longer battery life. I also have all my files set up the way i like in itunes so i give ipod the edge in that area aswell. M3k will be more file based. More on reddit.com