Fiio JM21 DAP USB DAC Performance

[ShinMolina]

I just received my Fiio JM21 this week, and I'm quite pleased with it. This is my first DAP running Android and I didn't know if I would like the experience or not. It works very well, the device is responsive and has enough output power to drive everything I have from Truthear Hexa to HD600 and Fostex T50RP Mk3. The device seemed to shut down once without pressing anything while playing music. This has only happened once a couple of days ago. Apart from that, everything seems to work properly.

As I saw in Fiio's website, the performance of the JM21 seems decent, achieving about 0.001-0.002% or 94-100dB THD+N. I hooked the JM21 to my Topping E2X2 Pro, which has some decent ADC, performance and looked at the spectrum of a pure 1kHz tone played from the DAP.

When the JM21 is working as a standalone DAP, the noise and distortion look pretty low, corroborating the specifications given by Fiio. But when you use the JM21 as a DAC or even connect a USB cable to the unit, the performance decreases significantly as the noise floor increases.

I currently don't have any USB isolator or anything like that to remove any possible ground loops that could affect the performance I'm measuring, since the standalone performance looks great. Would like your opinion on this matter or if I could do anything to get a more accurate result.

 

[ShinMolina]

Here are some pictures I forgot to add about the setup I used for the measurements.

 

[ppunter2015]

I think it looks very nice. I am looking for a new DAP as the battery of my shanling m6 pro is dying out. Thinking about this one for my next buy.

 

[monkeyboy]

I'm curious about this unit as well...I'm currently using an LG phone, but the battery is going and it's 50:50 that you break it changing the battery...I'm thinking about a Pixel with GrapheneOS, but you'd need a dongle, which I think would end up destroying the USB port...and I don't use any of the phone functions. But it seems like none of the DAPs are a performant as a phone dongle combination....

 

[ShinMolina]

This one doesn't compete in performance with the best dongles out there, but it measures well enough at a first glance and I can't find any differences in sound quality when compared to my E1DA 9038S G3 dongle.

I'm pretty happy with it. It has some minor bugs and in the latest firmware update the next and previous track physical buttons don't function as they should. But Fiio seems to be resolving the bugs and has done so for other previous devices.

 

[Zoide]

This one doesn't compete in performance with the best dongles out there

In what sense?

 

[ShinMolina]

In what sense?

When being used as a DAC connected to a PC. I feel that many dongles offer better measured specs for much less. Although, the things I measured, like THD, noise, IMD, and others, show that the JM21 should be indistinguishable from other dongle DACs.

I’ve now switched to an M21 and have noticed a significant audio delay when using it as a DAC. This is a known issue with some of Fiio's products. Some users have been able to minimize the delay by adjusting buffer size and sample rate, but I haven’t been able to eliminate it completely.

In my opinion, and as the device stands now, without any foreseeable updates to resolve these issues, I don’t recommend the JM21/M21 as a DAC. I didn’t purchase it for that use specifically, but it would’ve been a nice bonus if it worked properly.

 

[Somafunk]

In my opinion, and as the device stands now, without any foreseeable updates to resolve these issues, I don’t recommend the JM21/M21 as a DAC. I didn’t purchase it for that use specifically, but it would’ve been a nice bonus if it worked properly.

That’s the story with just about every Fiio product, excellent design, excellent features, excellent price, utterly piss poor U.I. and software/firmware implementation with very poor updates that do little to fix long term issues.

I’d like to buy a Fiio dap, or something like the cool looking BTR17 Bluetooth dac/amp as an alternative device compared to my Qudelix 5K but absolutely no chance of that happening until Fiio stop releasing new products every week and spend the money on a proper software development team

 

[Zoide]

That’s the story with just about every Fiio product, excellent design, excellent features, excellent price, utterly piss poor U.I. and software/firmware implementation with very poor updates that do little to fix long term issues.

I’d like to buy a Fiio dap, or something like the cool looking BTR17 Bluetooth dac/amp as an alternative device compared to my Qudelix 5K but absolutely no chance of that happening until Fiio stop releasing new products every week and spend the money on a proper software development team

Oh man, I just bought a BTR17 and am waiting for a 4.4mm cable to try it with my DCA E3 ... Wish me luck!

 

[Somafunk]

Oh man, I just bought a BTR17 and am waiting for a 4.4mm cable to try it with my DCA E3 ... Wish me luck!

, I’d like to try one if my 5K broke but I have an iPhone with aac so not much point in fancy BTR17 Bluetooth capabilities and the poor Fiio iOS app puts me off.

Quedelix must be working on an improved 5K as it’s 5+years old, better buttons, perhaps a screen etc

 

[ShinMolina]

To be honest, I was quite happy with my Fiio BTR15. I've owned almost every Bluetooth DAC in the BTR series since it launched, and in my opinion, the BTR15 was even better than the BTR7.

No latency, solid microphone, no signal loss, great sound quality... The BTR7 occasionally had some audio clicks and pops, but the BTR15 was flawless, its only real drawback was limited output power.

I’m not sure why I sold them and ended up with the M21. I wanted to free up my phone from storing music files, but my overall experience hasn’t improved, it has just changed.

 

[Somafunk]

I’m not sure why I sold them and ended up with the M21. I wanted to free up my phone from storing music files, but my overall experience hasn’t improved, it has just changed.

Perhaps an “alternative” could be this Tempotec V1 dap below, I ordered one last week for £55 due to pre-buy discount deals as it seems to do everything that the BTR17 does plus it runs the Hiby software that is used on the R1/R3 so it has fully fledged Dap capability in a smaller size than the BTR17….oh….it also has Tidal/Qobuz capabilities. It's just been shipped so I’ll see if it was worth it when it arrives next week, for the initial price of £55 I doubt I’ll be complaining.

Headphone Reviews and Discussion - Head-Fi.org

www.head-fi.org

https://www.aliexpress.com/item/1005009209242733.html?spm=a2g0o.order_detail.order_detail_item.3.6ad9f19cPa5Ajd

 

[Lifter59]

I had the JM21 and subsequently sold it due to the firmware issues. While I have similar firmware issues with several other Fiio DAP's I took a calculated risk and bought the M21. While it's a bit moree expensive than the JM21, I think it's a far more functional device and vastly more capable. I can also say that there have been minimal issues with functionality/firmware issues and I am quite happy with it. If you can swing the additional $, I think you will be much happier with it.

 

[bishop44]

Perhaps an “alternative” could be this Tempotec V1 dap below, I ordered one last week for £55 due to pre-buy discount deals as it seems to do everything that the BTR17 does plus it runs the Hiby software that is used on the R1/R3 so it has fully fledged Dap capability in a smaller size than the BTR17….oh….it also has Tidal/Qobuz capabilities. It's just been shipped so I’ll see if it was worth it when it arrives next week, for the initial price of £55 I doubt I’ll be complaining.

Headphone Reviews and Discussion - Head-Fi.org

www.head-fi.org

https://www.aliexpress.com/item/1005009209242733.html?spm=a2g0o.order_detail.order_detail_item.3.6ad9f19cPa5Ajd

@Somafunk Did you receive the Tempotec? What are your thoughts?

 

[Somafunk]

@Somafunk Did you receive the Tempotec? What are your thoughts?

To begin with it worked fine then it began to suffer issues which was rather weird?

Bluetooth dropped out for no reason
Streaming from tidal causes the unit to freeze then reboot.
Whilst playing through an album it will jump randomly throughout the track listing
Randomly reboots when skipping tracks/changing volume

New Firmware was finally released last week but not available for over the air/wifi update so I downloaded to micro sd card and updated firmware on the player

Factory reset, sd card firmware loaded/updated, switch off then on, insert sd card loaded with music, update music data base, switch off then on.

Seems to be working now, no tidal crashing which is a bonus, Bluetooth still dodgy as if I venture to another room it can occasionaly cut out but I use an iPhone, perhaps aac is the issue?, or perhaps my 7yr old iPhone XS is the issue?.

All in all for £55 I can't complain as some dongles cost more, music playback/dap functionality in a tiny unit not much larger than a packet of chewing gum is handy, can power all my iems/sennheiser HD490 without any issues, battery life is 10hours or so.

Screen is small, button placement could do with some work but those are minor foibles.

 

[bishop44]

To begin with it worked fine then it began to suffer issues which was rather weird?

Bluetooth dropped out for no reason
Streaming from tidal causes the unit to freeze then reboot.
Whilst playing through an album it will jump randomly throughout the track listing
Randomly reboots when skipping tracks/changing volume

New Firmware was finally released last week but not available for over the air/wifi update so I downloaded to micro sd card and updated firmware on the player

Factory reset, sd card firmware loaded/updated, switch off then on, insert sd card loaded with music, update music data base, switch off then on.

Seems to be working now, no tidal crashing which is a bonus, Bluetooth still dodgy as if I venture to another room it can occasionaly cut out but I use an iPhone, perhaps aac is the issue?, or perhaps my 7yr old iPhone XS is the issue?.

All in all for £55 I can't complain as some dongles cost more, music playback/dap functionality in a tiny unit not much larger than a packet of chewing gum is handy, can power all my iems/sennheiser HD490 without any issues, battery life is 10hours or so.

Screen is small, button placement could do with some work but those are minor foibles.

Thanks for the info. I think I'll put this on ice and see how they get on with the firmware. Cracking price though!

 

[ShadDynasty]

I'd like to add that with my unit, the 3.5mm output sounds substantially better than the 4.4 BAL. Any possible reason for this?

 

[ShadDynasty]

There is an "All To DSD" feature on the JM21 that converts all audio to DSD64 (even 48k family to DSD64 x 44.1). I've done some comparisons between that and normal DAC operations. My filter settings are on linear phase fast roll-off.

My testing equipment is the Audient Evo 4 interface capturing at 24-bit/88.2kHz. I connect the DAP to my interface via the 3.5mm jack into a 1/4" converter and into the instrument input on the interface. The gain is set to low with volume at 120 to match the ballpark of my use case (IEMs). Here are my results.

First, let's take a look at the filter at 44.1kHz without DSD upsampling (I use white noise):

Ignore the blue, that's the other unused channel.

And here is the same exact thing but with All To DSD on:

Looks worse.

I also conducted two impulse response tests at 44.1kHz with and without All To DSD. The impulse response itself is quite unremarkable but what is interesting is the elevated noise of the DSD upsampled signal. To show you the noise, the signal amplitude view is magnified. Take a look.

Without DSD up:

With DSD up:

Yikes.


And now, two more filter measurements, but this time at 48kHz with and without All To DSD.

Without DSD up:

With DSD up:

Not as bad as the 44.1kHz example, but native is still better.

Anyways, my conclusion is that the "All To DSD" feature is garbage.

 

[Nango]

Only 6h play time when listening from Wifi streaming on Iems..... Bad!!