FiiOM11 Plus Music Player MP3/MP4 High Resolution Audio Player (ESS)

I've had the Fiio M9 for 4 years now, so basically this review of the Fiio M11 Plus will be a comparison with that old workhorse. The first thing I noticed was how humongous this DAP was. Reading about how big it is doesn't quite prepare you. It's big and heavy, too big to fit comfortably in most pants pockets, unless they're cargo pants.My purchase came with a nice leather case and charging cord, but was missing the microsd card slot tool and some other cord I can't remember. I had to wait a few days for my 1 terabyte microsd card to arrive before trying to use it. Once I'd copied about 13000 music files onto the microsd card, I was impressed by how quickly I was able to build the music library. It took less than 20 minutes and I was expecting at least an hour.Like the M9, the M11 Plus uses an Android operating system so I was able to easily navigate my way around. It's quicker and more responsive than the M9. The sliding volume control is a far too sensitive so I quickly deactivated it.The bigger screen allows for better images of album art, and I was able to adjust the font size to my liking. The music sounds great, at least as good as the M9. The base is definitely punchier and with headphones there is a better soundstage.While this DAP can play for up to 14 hours (vs 8-10 for the M9), it takes some 3 hours to charge it from 15% to 100%, whereas the M9 could fully charge in less than an hour. And when using it to drive a car stereo system or bookshelf speakers, the charging rate slows to a crawl.I'll be using this at home with my living room stereo system or my headphones, but when on the go (travelling, driving, walking, flying), I'll stick to the more convenient and almost as great sounding M9.Jul 5 Update:It's been a couple of months of fairly heavy use so here's an update.I will start with the good. Using the Fiio Music app, there's a special lab feature where you can replace the equalizer panel "with a parametric EQ panel so that you can adjust the frequency bands manually." I did this and boy did the sound improve! The bass became livelier. My M9 couldn't match the sound that I got, no matter how I adjusted its equalizer.Now the bad. Sometimes, during the first 10 seconds of a song, there's a point where there's a stutter in the music (as if the song was ripped from a skippy CD). If I'm listening casually I don't notice it, but if I'm actively listening, it's noticeable and annoying. When I restart the song, it plays fine without the stutter. I'd say it happens 40% of the time. Not acceptable for a device that costs several hundred dollars.July 14 Update:So yesterday I decided to upgrade the Fiio Music app on my M11 Plus ESS from version 3.1.5 to 3.1.7, with the hope that the momentary stutter in the first few seconds of a song would go away. And lo-and-behold, it seems to have done the trick (knock on wood). For now I'll upgrade my review to a 5.And since I was in a happy mood after that, I decided what the heck let me upgrade the Fiio Music app on my M9 to the same version 3.1.7. It worked, and now the M9 has the same parametric equalizer that improved the sound. So now the M9 and M11 sound pretty much the same to my ears. But the M9 works a little slower with the new app, and uses power a little faster.

In 2021, I purchased the FiiO M11 Pro to replace my aging Astell&Kern AK380. As much as I enjoyed the AK380, the M11 Pro is all around the better digital audio player and substantially less expensive. I recently purchased the M11 Plus, ESS version. I pondered getting the LTD version but decided to get the ESS version for the better specs and thinking that the DAC chips would make little if any difference in the sound quality. I don't regret that decision because I love the sound of the M11 Plus ESS. The sound of my earbuds (wired and wireless) seem to be a little better on the M11 Plus compared to the M11 Pro. Not a leap forward but a noticeable improvement. Especially for the Jabra Elite 85t and 7 Pro that use the AAC codec. The M11 Pro does not support AAC but the M11 Plus does and it makes a significant difference. It breaths life into the 85t and 7 Pro. The aptX and LDAC codecs are supported by both the Pro and Plus but the Sennheiser MTW2 and Sony XM4 sound slightly better with the Plus. It could be that I'm interpreting the slight difference in sound between the AKM and ESS DAC chips as better for the ESS. I also evaluated the sound quality with the Shure SE846 and Westone W60 and was impressed by what I heard. Of course, sound quality is entirely subjective and you may not feel the same. I can only say that, to me, the M11 Pro, which uses AKM AK4497 chips, sounds sweeter (smoother) and somewhat laid-back while the M11 Plus, which uses ESS Saber ES9068AS chips, sound clearer and more aggressive. Your preference will determine which you should buy. However, the LTD version is in short supply due to limited availability of the AK4497 DAC chips.All the players I've previously owned used Burr-Brown, Cirrus Logic or AKM DAC chips. The M11 Plus is the first player I've owned that uses an ESS Sabre DAC chip and I'm really enjoying it. The M11 Plus ESS is an exceptionally good player at this price point. I can't imagine what the M17 sounds like. However, after hearing the M11 Plus, I have no desire to audition the M17. I'm happy with the M11 Plus.My only "less than positive" comments are in regard to its size, weight and interface. The M11 Plus is larger and heavier than the M11 Pro. The Pro felt comfortable in my hand while the Plus feels a little awkward and heavy. The larger screen is nice but not really necessary. I would have liked the Plus better if it were similar in size and weight to the Pro. The touch volume slider is too sensitive and I often change the volume without intending to. It's also placed right where my thumb rests when I hold the player in my left hand. That was not working for me so I disabled the volume touch slider in the setup options and use just the rocker function of the volume switch to make changes. The screen interface is also different so there is a small learning curve involved if you upgrade from the Pro to the Plus. Not a disaster but a little inconvenient if you plan to use both like I do.I rate the M11 Plus ESS at 4.5 stars rounded up to 5. It is the best digital audio player I have owned at any price point.