FiiO M11 Plus ESS

FiiO M11 Plus ESS

23 June 2022 0 By Petros Laskis

Effectively Superior Sound

Pros: + Reference sound with superb balance between technicalities and musicality
+ Transparent and crystal clear
+ Natural timbre and minimum digital glare
+ Excellent soundstage
+ Powerful amplifier
+ Great battery duration
+ Fast and responsive UI
+ Quite compact and not too heavy
+ Three headphone outputs
+ Dedicated balanced and single ended line outputs
+ Elegant and stylish
+ High quality protective case

Cons: – Not as powerful as the competition
– Not as compact and lightweight as some other models
– Information bar will not display gain and filter settings

The review sample was kindly provided free of charge in exchange for my honest and subjective evaluation, I only paid import fees and tax.
I haven’t received any monetary or any other kind of compensation and I don’t use affiliate links.
The retail price is $700 and you can buy it from here.

M11 Plus ESS

The M11 Plus ESS is the newest version of the much acclaimed M11 Plus LTD (https://www.head-fi.org/showcase/fiio-m11-plus-ltd.25171/review/26267/) which had dual AK4497 DAC chips and is now discontinued.
The chip shortage forced FiiO to replace it with ES9068AS DAC chip from ESS and thus the M11 Plus ESS was born without any further increase in the retail price.

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Technical highlights

The M11 Plus ESS features two ES9068AS DAC chips in a fully balanced configuration while low-pass filters have been replaced from OPA1662*2 to OPA927*2, carefully matching the new chipset.
Power output has been slightly increased to 660mWPC at 32Ω instead of 588mWPC for the AKM version.
Furthermore, the battery life of the new M11 Plus ESS is now improved from 11.5H on the AKM variant to 14H.

Audio data is passed through FiiO developed 4th generation FPGA which works together with two custom NDK femtosecond crystal oscillators.
The music player can handle virtually all existing file formats up to 32bit-768kHz in PCM, native DSD up to DSD512 and MQA decoding even in third party apps.
In USB-DAC mode is also an MQA 8x rendered.
The player supports FiiO’s “All to DSD” algorithm.

The M11 Plus ESS uses two of the same feed forward error correction THX AAA-78 modules in a fully balanced configuration.
Special care has been given to the power supply which features independent low dropout regulators for all critical parts of the circuit while many measures have been taken to ensure excellent temperature management.
The circuit has a modular design ensuring that all digital and analog sections are totally separated and shielded from each other.

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The unit is powered by a Qualcomm snapdragon 660 processor aided by 4GB of fast DDR5 ram and 64GB ROM, so it can handle multiple tasks and applications very smoothly like a flagship smartphone without lagging.
The operating system is customized Android 10 with official Play support while you can always switch to Pure Music mode.

The user experience is further enhanced thanks to the large 5.5″, high resolution (720*1440) screen which has vibrant colors with excellent viewing angles and visibility while it is fast and responsive.

Bluetooth connection

The M11 Plus ESS features a two way Bluetooth module.
Besides support for DLNA and AirPlay, newly added is the support for AAC codec for Bluetooth reception and transmission for iPhone owners.
Bluetooth transmission supports SBC/AAC/aptX/aptX HD/LDAC while reception is limited to SBC/AAC/LDAC.
Bluetooth pairing is done easily while connection is stable with a good working distance.
Sound quality is very good given the nature of the Bluetooth protocol and you can use the M11 Plus ESS as a source for your Bluetooth headphones.

Full technical specifications are available here.

Design and build quality

The ESS version measures exactly the same as the LTD at 136.6×75.7×17.6mm, weighing about 310g.
Size and weight are ideal for everyday carry and one handed use.
The chassis of the player is made from CNC machined aluminium featuring FiiO’s new hexagonal honeycomb design elements.
The back panel has a “diamond-cut” glass design that bounces light off in a mesmerizing way.
The M11 Plus ESS is very elegant and beautiful looking so I much prefer using it without the protection case.
Build quality is excellent and the unit comes with a screen protector pre-installed from the factory.
The only difference from the limited version is that the touch – sensitive side panel, which is used for controlling the volume, is now made from carbon fiber instead of smooth plastic.
The new material matches better with the overall appearance of the unit while it offers more controlled slide adjustment of the volume.

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I/O

At the bottom part of the unit there are located the three headphone outputs (4.4mm and 2.5mm balanced plus 3.5mm single ended) and the USB 3.0 type-C port.
The 4.4mm output can also be configured as a real balanced line out, bypassing the amplification stage, with fixed or variable level.
The same applies to the 3.5mm single ended output which can also be set as a coaxial digital output.
The high speed USB 3.0 port is used for fast file transfers, charging, connecting to any computer in a USB DAC mode or for using the M11 Plus ESS as a digital transport.
You can also hook an external USB OTG thumb drive.

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User interface

Aside from the touch screen, controlling the unit is done with the aid of several physical buttons and the sliding touch panel which is located at the left side of the chassis.
The sliding touch panel working principle can be customized through the OS.
Highly customizable is also the unique and very useful shortcut button that is located underneath the touch panel.
It can be set to perform a specific, single press action, like one click to switch between the low pass filters.
The ON/OFF button has embedded a multicolor LED that can be set as what to display.
At the right side of the chassis you will find the three classic buttons for controlling play/pause, previous and next track, the hold switch and the micro SD card slot.

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User experience

As noted above using the M11 Plus ESS is a straightforward, smooth and hassle free experience.
The player is fast and responsive, WiFi reception is excellent and you can download all your favorite applications, multitask or switch to Pure Music mode which further maximizes sound performance by killing all unnecessary tasks.
The unit can be used one handed, it is compact enough to fit in a larger pocket, it doesn’t get too hot and it has great battery duration which I roughly measured at about 11-12 hours of streaming music from the balanced output.
There are three gain settings while you can choose between five different working modes (Android, Pure Music, Bluetooth reception, USB DAC and AirPlay) from the drop down menu.
WiFi music transport is also available and the player supports all Android 10 features like gesture controls, dark theme etc.

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Software omissions

There are only a couple of minor issues, the same as with the M11 Plus LTD or the M17 that FiiO are taking too long to fix.
First of all, you cannot select the low pass filter from the drop down menu and you have to open the full settings menu in order to do so.
Then, the top information bar will not display the gain and filter settings at a glance, so you have to rely on your memory to remember your selection.
And while this is not much of an issue for the digital filter, it sure is for the gain setting.
And a serious one, because you can accidentally blow a sensitive earphone or damage your hearing when you frequently switch from full sized headphones to sensitive IEMs that require different gain settings.
This is something that ought to be fixed immediately.

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Accessories

The M11 Plus ESS comes with a glass screen protector pre-installed from the factory.
A premium leather case of the highest quality is included to help you protect the player from accidental drops.
The case has a lid with a secure clip so there is no risk for the player to accidentally slip outside it.
The unit doesn’t get hot even with the case applied.
You also get a coaxial adapter and a USB 3.0 cable for charging and connecting to a PC.

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Associated gear

As per usual practice, the M11 Plus ESS was burned for more than 150 hours before critical listening.
I have used most of my regular headphones and IEMs like the Focal Clear Mg, HiFiMan Arya V3, Sennheiser HD8XX, Meze Liric, FiiO FDX and Unique Melody MEXT among others.
The balanced output is superior both for the slightly better sound quality and the extra power but the single ended output is also good.
I have briefly tested the “All to DSD function” without performing any detailed listening comparisons as I am not fond of further digital processing.

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Power output

The FiiO M11 Plus ESS is powerful enough to smoothly run all the normal headphones without even reaching its upper power limits.
Dynamic range is excellent and the M11 Plus ESS can become very impactful when the music commands for large dynamic swings.
As an example the Focal Clear Mg was already loud enough and thunderous at roughly 75 of 120 volume steps, at high gain from the balanced output.
It is not as powerful as some of the competition, like the iBasso DX240, but as long as you don’t have any super difficult to drive headphones, then you are not going to run out of power.
At the same time the noise floor is literally inaudible making the M11 Plus ESS an excellent companion for your super sensitive IEMs.

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Listening impressions

Exceptionally balanced is the key word for describing the M11 Plus ESS sound performance.
Balanced in the way that equilibrates the excellent technicalities with the deep musical expression without favoring one part at the expense of the other.
Absolutely linear frequency response with great extension, ultimate transparency and precision but without sounding analytical, artificial, rough, boring or bright.
The sound delivery is very mature, this is a player to boot from the beginning and start listening to your favorite music without the need to worry about careful headphone matching or genre selection at least as long as you respect the demand for high quality raw material due to the exposing and unforgiving nature.
Feed it with some well recorded music to discover that the player is headphone agnostic, it is as enjoyable with the Focal Clear Mg as well as with the HiFiMan Arya V3 and with all kinds of music.
The sound is cohesive and homogeneous, from the deep and imposing low end to the lush, smooth and finely articulated mid range, all the way up to the vividly energetic treble which is by no way harsh or fatiguing.
The player is balanced in all of its parameters, slightly warmish as not to sound cold, full bodied but not too visceral, crystal clear but not ice glassy, fast but not hasty, detailed and resolving but not analytical, layered and precise but not detached, live and sparkling but not too enthusiastic.
Digital glare is kept on the bare minimum while timbre is sufficiently natural with an almost lifelike, organic texture.
Acoustic instruments and human voices are reproduced quite close to reality while the M11 Plus ESS is equally at home with synthesized electronic music.
You don’t need to listen to something complicated, just a solo instrument like the magnificent lute is enough to get a glimpse of the highly musical and harmoniously intense sound performance.

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I kept listening to my favorite music for hours and honestly I wasn’t able to spot anything bothering or distracting.
Of course I can see some users wanting a slightly more technical player like the M17 and some others searching for better liquidity or lushness like that offered by the DX300.
But the really great achievement with the M11 Plus ESS is that it is positioned just right in the middle, offering an amazingly well blended sound performance that is difficult not to please, no matter the headphone used or your music tastes.
Soundstaging is exceptional for a portable player, with the right headphone the M11 Plus ESS will reward you with a three dimensional and holographic soundscape, well sculptured images, exemplary positioning accuracy and deep communication of the hall ambience.
A great example was listening to the following recording of Monteverdi’s opera “Il Ritorno d’ Ulisse in Patria ” where with the aid of the HiFiMan Arya V3, I was literally transported into the wonderful Château de versailles, watching and listening to the performers.

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Selected comparisons


vs iBasso DX240/Stock AMP ($949)

The iBasso DX240 is undeniably the most portable and pocket friendly high end player in the market.
Measuring just 124×71.5×19.4mm and weighing a mere 240g is slightly more compact and lightweight than the M11 Plus ESS making for the perfect commuting companion but miniaturizing costs $250 more.
Additionally it has a smaller 5″ screen and misses a 4.4mm balanced headphone and line output.
The key structural difference between the two players is that the DX240 supports the interchangeable AMP-card modular system that gives you the opportunity to further customize the sound to your liking.
I am not going into detailed technical and software comparison, both players are fast, responsive and user friendly but the DX240 has the edge when it comes to one handed use.
Sound-wise are quite close, they share more or less the same sound signature with some minor differences.
The DX240 is slightly more technical, bass is more tight and controlled with better separation and a touch more dynamic but it loses some of its weight when compared to the M11 Plus ESS.
On the other hand, M11 Plus ESS is more suave in the mids and the treble with a slower note decay where the DX240 is drier and thinner.
The DX240 is bolder in its presentation, a little more aggressive and faster with better separation and space between the lines but not that much as to sound detached.
Soundstage is wider on the DX240 with increased positioning accuracy but not as holographic and layered as in the M11 Plus ESS.
Swapping to the AMP8 MK2 and the DX240 becomes more analogue sounding, it gains in body weight, soundstage dimensionality and timbre texture while it retains the excellent technicalities.
But the M11 Plus ESS strikes the golden ratio between these two amplifier modules and while it is not further customizable it doesn’t really matter because it sounds very balanced without the further need to adjust something.
Both players are a gem and as always you are called to carefully judge your personal needs and then decide which player suits you the best.

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vs FiiO M11 Plus LTD

Identical physical appearance and user experience with some variations regarding the overall sound presentation.
Differences are subtle but they do exist giving each player some unique characteristics.
Both have a linear frequency response while they are transparent with the same great technical performance.
The M11 Plus LTD is a touch more relaxed in contrast to the bolder and more enthusiastic ESS version.
The mid range on the LTD is just slightly more lush and warmer with a fuller texture but not as firm and finely sculptured as in the ESS.
The same goes for the treble which is a touch slower in the decay, not as sharp and accurate but it sounds just a bit more relaxed and natural.
Bass is on the same, masterclass, level for both players while the ESS version has the minor edge on overall clarity and detail retrieval.
The biggest difference is in the soundstage where in the ESS is definitely more expanded in the width, it offers better positioning accuracy, deeper layering and above all a greater communication of the recording ambience.
And now the answer to the million dollar question: I own the M11 Plus LTD, should I buy the ESS version?
Well, honestly I wouldn’t, the LTD is an excellent sounding player but I don’t consider it neither as an upgrade nor as a downgrade.
Both are among the best digital audio players in the market, more alike than different, just another flavor of the same great recipe.
And for all fans of FiiO house sound who haven’t made it to buy the LTD version, don’t worry, just go grab the ESS and be wholly satisfied.

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In the end

A suitable acronym for the ESS version of FiiO’s M11 Plus would read something like “Effectively Superior Sound”.
Balanced to the bone, the M11 Plus ESS is a player that offers instant listening satisfaction just from the beginning without the need to worry about headphone matching or music selection.
With excellent sound performance and technicalities, superb build quality, compact size, good battery duration and hussle free user experience, the M11 Plus ESS is one of the best players in the market that you can go and buy without having a second thought.

Test playlist

Copyright – Petros Laskis 2022.