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Fiio Q5s Portable DAC & THX Headphone Amp Review

amirm

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#1
This is a review and detailed measurements of the portable Fiio Q5s USB DAC and optional THX headphone amplifier (AM3D). It was kindly sent to me by a member. Q5s by itself costs US $300 from Amazon including Prime shipping. The AM3D THX AAA module costs an extra US $150 on Amazon including Prime shipping.

As it happens, the company was also kind enough to send one to me last year which I had yet to review! So I got a chance to test that version as well but briefly.

The form factor of Q5s is similar to other pricier stand-alone DAC/Headphone amps with chunky metal box:

Fiio Q5s USB DAC Bluethooth Portable Headphone Amplifier THX Audio Review.jpg


There is a single micro USB connector at the bottom that provides both charging and also data connection to the PC. To use the THX module, you have to unscrew the standard one that comes with it ("AM3E") and plug in the THX one:

Fiio Q5s USB DAC Bluethooth Portable Headphone Amplifier THX Module Back Audio Review.jpg


The volume control uses an ADC which converts is value and that is used to then adjust the level on both channels. This provided perfect channel matching but made me concerned about the performance of the volume control chip used in the middle.

On top you have Line In and Line Out. On the bottom on the THX module you have the 3.5 mm unbalanced jack and 2.5mm balanced.

DAC Audio Measurements
I connected the Q5s using USB and Line out and fired our normal dashboard test and got this disappointing result:

Fiio Q5s USB DAC Bluethooth Portable Headphone Amplifier THX Audio Measurements.png


Look at the high spray of harmonic distortion to the right of our 1 kHz tone (the tall spike). I finished running all the DAC and headphone test which took two hours. I then went to graph the SINAD above in my spreadsheet and I see that I already had an entry for Q5s at SINAD of 100 db! What the heck?

I dig up the old unit with standard headphone amp and measure it and it too produces 90 dB SINAD. Frustration is starting to set in.

Aha! Maybe I used the headphone out. I plug the output cable into that and SINAD indeed shoots up to nearly 100 dB!

Fiio Q5s USB DAC Bluethooth Portable Headphone Amplifier Standard Audio Measurements.png


Back to the member unit with THX module it too measures well with headphone out:

Fiio Q5s USB DAC Bluethooth Portable Headphone Amplifier THX HP Out Audio Measurements.png


With the headphone amp output, Q5s squeezes into second tier of all DACs tested:

best portable headphone amp and dac.png


At this point I realize all the tests are invalidated and I have to spend two more hours testing them all. Instead of punching my fist into the monitor, I calmed myself and ran the IMD test again, only to see no improvement whatsoever!

Fiio Q5s USB DAC Bluethooth Portable Headphone Amplifier THX IMD Audio Measurements.png


Why is IMD "SINAD" so poor at just 78 dB? The mystery was solved later when I ran the THD+N versus frequency:

Fiio Q5s USB DAC Bluethooth Portable Headphone Amplifier  THD+N vs Frequency THX Audio Measure...png


Oh brother! Even getting rid of the effects of the poor DAC filter, there is a sharp rise in distortion as frequencies get lower. Dashboard SINAD is using a 1 kHz tone which doesn't see that. But IMD test tones do because it is the combination of 60 Hz and 7 kHz.

I fire up the analyzer at 20 Hz and get this horror show:

Fiio Q5s USB DAC Bluethooth Portable Headphone Amplifier THX FFT Audio Measurements.png


Our SINAD now is nearly half as much it was in the dashboard 1 kHz tone!

I ran a new test to show the issue in "time domain:"

Fiio Q5s USB DAC Bluethooth Portable Headphone Amplifier THX 20 Hz Residual Audio Measurements.png


The red sine wave is the 20 Hz tone. The blue one is the difference between it, and a pure 20 Hz sine wave, multiplied by 100 (otherwise the variations are too small to see). This is called the "residual" (null) signal. The highest variation is during negative swings of the power supply indicating poor capacity there.

Back to the DAC filter, this is what it looks like:

Fiio Q5s USB DAC Bluethooth Portable Headphone Amplifier THX Filter Audio Measurements.png


Gosh, here we go again catering to audiophile myths with such slow filters that allow a ton of ultrasonic junk to be produced by the DAC for no good reason. Worse yet, it causes the audible band to have an early droop:

Fiio Q5s USB DAC Bluethooth Portable Headphone Amplifier THX Frequency Response Audio Measurem...png


As is typical, the roll off starts at 10 khz and by 20 kHz we are down a whopping 4 dB! The younger audience that uses this likely had the hearing that goes up that high so will be cheated out of some of the highs in their music. Maybe they will confused that for fidelity.

But the story is not on the right. It is on the left! What is that notch? At first I thought the analyzer was loosing data but it was not. Zooming in we clearly see the issue:

Fiio Q5s USB DAC Bluethooth Portable Headphone Amplifier THX Frequency Response Zoomed bug Aud...png


I tested the above on my other Q5s and it had the same problem with line out. Thankfully this is one test that improved with headphone out without this problem with either output module.

Why did they put this in there? It can't be an accident. Was there some audible noise there and they decided to filter it out or something? Blood is starting to boil big time by this point.

I had run the 32-tone test signal simulating "music" and got this poor output:

Fiio Q5s USB DAC Bluethooth Portable Headphone Amplifier THX Multitone Audio Measurements.png


I thought no problem, I just switch to headphone output and the problem would be gone. No it was not! The output was identical out of the "THX" module! That power supply/low frequency issue is causing severe problem with this test.

Not everything is bad news. Dynamic Range is fine:
Fiio Q5s USB DAC Bluethooth Portable Headphone Amplifier THX Dynamic range Audio Measurements.png


As is jitter:

Fiio Q5s USB DAC Bluethooth Portable Headphone Amplifier THX jitter Audio Measurements.png


Linearity is perfect:
Fiio Q5s USB DAC Bluethooth Portable Headphone Amplifier THX Linearity Audio Measurements.png


Headphone Amplifier Tests
Here is our 3.5mm headphone output dashboard using the THX AAA module:

Fiio Q5s USB DAC Bluethooth Portable Headphone Amplifier THX HP Audio Measurements.png


77 dB SINAD? How can this be? A THX module with this kind of performance? And this is in low gain with output not going much past 1.1 volt -- something a dongle can do better.

Switching to balanced output improves things:

Fiio Q5s USB DAC Bluethooth Portable Headphone Amplifier THX HP Balanced Audio Measurements.png


But still nothing impressive.

Signal to noise ratio is worse than using the DAC:
Fiio Q5s USB DAC Bluethooth Portable Headphone Amplifier THX HP Dynamic Range Audio Measurements.png


Lowest noise portable headphone amplifier 2020.png


The low output voltage kills any prospects of good power delivery into 300 ohm load:

Fiio Q5s USB DAC Bluethooth Portable Headphone Amplifier THX HP Power at 300 Audio Measurements.png


At max gain and allowing for the distortion to rise we only have 18 milliwatts. If I measure at the knee of the curve as I usually do, power will drop to just 3 or 4 milliwatts!

I compared this to the standard module in high gain:

Fiio Q5s USB DAC Bluethooth Portable Headphone Amplifier THX HP Power at 300 AM3E Standard Aud...png


The noise level is a bit higher but both suffer identically from distortion and produce the exact same power.

Switching to 300 ohm gives us more power but still nothing that great:

Fiio Q5s USB DAC Bluethooth Portable Headphone Amplifier THX HP Power at 33 Audio Measurements.png


Fortunately balanced output does deliver more power:

Fiio Q5s USB DAC Bluethooth Portable Headphone Amplifier THX HP Power at 300 Balanced HP Audio...png


But with lots of distortion again.

I tested the frequency response and as I noted earlier, it doesn't have that notch:
Fiio Q5s USB DAC Bluethooth Portable Headphone Amplifier THX HP Frequency Response Audio Measu...png


Listening Tests
Please have some common sense. In the mood I am at the end of the above measurements puts me in no mood to listen to this device...

Conclusions
This was a painful review. So many variations to test. So many odd results. Two different devices. Two different amps. Three different outputs. Two different inputs. Maybe there is some explanation for the odd results that I am seeing but frankly, I don't have the patience to dig in more to find out. I see the words "THX" on a headphone amp and I expect world class performance. How did these measurements qualify for THX logo? What explains simple failures in frequency response of the line out?

I should say the company is very nice and cordial to deal with. But ultimately I have to go by what I have in front of me. Sadly it is not a functional product in my view. Yes, it produces sound. Yes, most people won't hear these issues but you are paying for great performance and you deserve to get it.

Needless to say, I can't recommend the Q5s with or without THX amplifier module.

-----------
As always, questions, comments, recommendations, etc. are welcome.

The panthers are asking for "fall" clothing. I keep telling them that is two months away but they don't listen. They say all the sales are now. With so many of them, no way I can afford to get them all new outfits. So please help me by donating what you can using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
 

YSC

Active Member
Joined
Dec 31, 2019
Messages
263
Likes
97
#5
This is a review and detailed measurements of the portable Fiio Q5s USB DAC and optional THX headphone amplifier (AM3D). It was kindly sent to me by a member. Q5s by itself costs US $300 from Amazon including Prime shipping. The AM3D THX AAA module costs an extra US $150 on Amazon including Prime shipping.

As it happens, the company was also kind enough to send one to me last year which I had yet to review! So I got a chance to test that version as well but briefly.

The form factor of Q5s is similar to other pricier stand-alone DAC/Headphone amps with chunky metal box:

View attachment 76539

There is a single micro USB connector at the bottom that provides both charging and also data connection to the PC. To use the THX module, you have to unscrew the standard one that comes with it ("AM3E") and plug in the THX one:

View attachment 76540

The volume control uses an ADC which converts is value and that is used to then adjust the level on both channels. This provided perfect channel matching but made me concerned about the performance of the volume control chip used in the middle.

On top you have Line In and Line Out. On the bottom on the THX module you have the 3.5 mm unbalanced jack and 2.5mm balanced.

DAC Audio Measurements
I connected the Q5s using USB and Line out and fired our normal dashboard test and got this disappointing result:

View attachment 76541

Look at the high spray of harmonic distortion to the right of our 1 kHz tone (the tall spike). I finished running all the DAC and headphone test which took two hours. I then went to graph the SINAD above in my spreadsheet and I see that I already had an entry for Q5s at SINAD of 100 db! What the heck?

I dig up the old unit with standard headphone amp and measure it and it too produces 90 dB SINAD. Frustration is starting to set in.

Aha! Maybe I used the headphone out. I plug the output cable into that and SINAD indeed shoots up to nearly 100 dB!

View attachment 76542

Back to the member unit with THX module it too measures well with headphone out:

View attachment 76544

With the headphone amp output, Q5s squeezes into second tier of all DACs tested:

View attachment 76545

At this point I realize all the tests are invalidated and I have to spend two more hours testing them all. Instead of punching my fist into the monitor, I calmed myself and ran the IMD test again, only to see no improvement whatsoever!

View attachment 76547

Why is IMD "SINAD" so poor at just 78 dB? The mystery was solved later when I ran the THD+N versus frequency:

View attachment 76548

Oh brother! Even getting rid of the effects of the poor DAC filter, there is a sharp rise in distortion as frequencies get lower. Dashboard SINAD is using a 1 kHz tone which doesn't see that. But IMD test tones do because it is the combination of 60 Hz and 7 kHz.

I fire up the analyzer at 20 Hz and get this horror show:

View attachment 76549

Our SINAD now is nearly half as much it was in the dashboard 1 kHz tone!

I ran a new test to show the issue in "time domain:"

View attachment 76550

The red sine wave is the 20 Hz tone. The blue one is the difference between it, and a pure 20 Hz sine wave, multiplied by 100 (otherwise the variations are too small to see). This is called the "residual" (null) signal. The highest variation is during negative swings of the power supply indicating poor capacity there.

Back to the DAC filter, this is what it looks like:

View attachment 76551

Gosh, here we go again catering to audiophile myths with such slow filters that allow a ton of ultrasonic junk to be produced by the DAC for no good reason. Worse yet, it causes the audible band to have an early droop:

View attachment 76552

As is typical, the roll off starts at 10 khz and by 20 kHz we are down a whopping 4 dB! The younger audience that uses this likely had the hearing that goes up that high so will be cheated out of some of the highs in their music. Maybe they will confused that for fidelity.

But the story is not on the right. It is on the left! What is that notch? At first I thought the analyzer was loosing data but it was not. Zooming in we clearly see the issue:

View attachment 76553

I tested the above on my other Q5s and it had the same problem with line out. Thankfully this is one test that improved with headphone out without this problem with either output module.

Why did they put this in there? It can't be an accident. Was there some audible noise there and they decided to filter it out or something? Blood is starting to boil big time by this point.

I had run the 32-tone test signal simulating "music" and got this poor output:

View attachment 76554

I thought no problem, I just switch to headphone output and the problem would be gone. No it was not! The output was identical out of the "THX" module! That power supply/low frequency issue is causing severe problem with this test.

Not everything is bad news. Dynamic Range is fine:
View attachment 76555

As is jitter:

View attachment 76557

Linearity is perfect:
View attachment 76556

Headphone Amplifier Tests
Here is our 3.5mm headphone output dashboard using the THX AAA module:

View attachment 76558

77 dB SINAD? How can this be? A THX module with this kind of performance? And this is in low gain with output not going much past 1.1 volt -- something a dongle can do better.

Switching to balanced output improves things:

View attachment 76559

But still nothing impressive.

Signal to noise ratio is worse than using the DAC:
View attachment 76560

View attachment 76561

The low output voltage kills any prospects of good power delivery into 300 ohm load:

View attachment 76562

At max gain and allowing for the distortion to rise we only have 18 milliwatts. If I measure at the knee of the curve as I usually do, power will drop to just 3 or 4 milliwatts!

I compared this to the standard module in high gain:

View attachment 76563

The noise level is a bit higher but both suffer identically from distortion and produce the exact same power.

Switching to 300 ohm gives us more power but still nothing that great:

View attachment 76564

Fortunately balanced output does deliver more power:

View attachment 76565

But with lots of distortion again.

I tested the frequency response and as I noted earlier, it doesn't have that notch:
View attachment 76566

Listening Tests
Please have some common sense. In the mood I am at the end of the above measurements puts me in no mood to listen to this device...

Conclusions
This was a painful review. So many variations to test. So many odd results. Two different devices. Two different amps. Three different outputs. Two different inputs. Maybe there is some explanation for the odd results that I am seeing but frankly, I don't have the patience to dig in more to find out. I see the words "THX" on a headphone amp and I expect world class performance. How did these measurements qualify for THX logo? What explains simple failures in frequency response of the line out?

I should say the company is very nice and cordial to deal with. But ultimately I have to go by what I have in front of me. Sadly it is not a functional product in my view. Yes, it produces sound. Yes, most people won't hear these issues but you are paying for great performance and you deserve to get it.

Needless to say, I can't recommend the Q5s with or without THX amplifier module.

-----------
As always, questions, comments, recommendations, etc. are welcome.

The panthers are asking for "fall" clothing. I keep telling them that is two months away but they don't listen. They say all the sales are now. With so many of them, no way I can afford to get them all new outfits. So please help me by donating what you can using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
That is poor performance for a company used to produce great budget dap... ok maybe now I can be happier with my Sony zx300, will get this with even worse performance and need my phone as source if I didn’t buy the Sony
 

A Surfer

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#6
Yikes, I get that the major issues seen here aren't audible, which might explain why I have generally enjoyed the Q5s/AM3D combination using the 4.4mm balanced input, but you would really expect/demand better engineering from FiiO. This is indeed a disappointment, but I am extremely glad that I sent the Q5s and AM3D to ASR to be measured.

Subjectively it does sound nice with my Edition X V2 and the Pioneer SE Monitor 5 that I have used with the balanced out, but that is still no excuse for results like this. FiiO, seriously, you should do much better work than this. Thank you to Amir for the disproportionately hard work that he had to put into this review. Now we know.
 

Maxicut

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#9
Terrible results for the dollars. Jitter is pretty good though, so it probably sounds OK to listen to
 

Robbo99999

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#13
Wow, better question to ask is...what is right about this device!? I'm struggling to answer that, and for the princely sum of $450 you get to own one, joy! Well that's the good thing about these reviews, especially for things like DACS that normally measure acceptably and therefore generally thought to be one of the least important things in the audio chain..... it's good to find the lemons for proper avoidance!
 
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#14
I have the older model, Q5, I thought it sounds quite good. Once I thought of upgrade to Q5s, now I feel lucky did not do the upgrade.
 

A Surfer

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Joined
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Messages
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#15
I have the older model, Q5, I thought it sounds quite good. Once I thought of upgrade to Q5s, now I feel lucky did not do the upgrade.
This was my Q5s reviewed here, and I still have the original Q5 as well. I suspect both would measure very much the same and while it may be surprising given the results, subjectively they both sound decent actually. I do agree that based on these results it would be very difficult to justify the money that is being asked by FiiO for this combination. Quite surprising, but that is exactly the reason I sent it in for review. Sometimes you need to shake the tree to see what falls out.

Hopefully FiiO responds to the professional critique much the way Schiit did with the Modius and improve their engineering standards.
 

Veri

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#16

F1308

Active Member
Joined
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#17
So when I see a Hi-Res AUDIO sticker on a product, it means Hi- Res files will be reproduced, but the quality of the sound is not guaranteed at all.
Planning for an ASR sticker is a must from now on...!!!!
Please, do.
 

Maxicut

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Joined
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#19
Umm. Jitter isn't exactly the end-all measurement. In fact, if there were one thing I'd say is hard to say that to be very audible, it's jitter sidebands.
http://www.sereneaudio.com/blog/what-does-jitter-sound-like try it for yourself. Unless there's something truly funky going on, it's generally OK.
True, but it's the most important thing in making a digital file sound analogue to your ears. Anyway, no argument from me
 
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