This is a review and detailed audio measurements of the 9th generation Amazon Fire 7 headphone capability. It was kindly purchased new and dropped ship to me months and months ago! I see it going for US $50 right now but the owner paid just $30 for it! That is a remarkable price for a full function tablet. If it has good audio performance, it will be a great alternative to digital audio players (DAPs).
This is relative small tablet at 7 inch but then again, much larger than any DAP:
Aspect of price subsidy is abundant in constant nagging it does to sign up for various Amazon services. Even though we use Amazon shopping everyday and I don't have an ill opinion of the company, even I was annoyed with so much pushing. They slow down a machine that is already rather slow to operate.
My favorite media player -- Roon -- complained that resolution was too low and wanted to run full screen which I let it. There were a few second pauses at times trying to navigate my playlist and touching seemed to not work at times. Overall though, the large screen and familiar apps is far, far better than anything a DAP has to offer. The main issue then is audio performance so let's measure that.
Amazon Fire 7 Measurements: Audio
I started my testing with USB charging cable plugged into my usual source (the hub in my monitor which is fairly clean):
Output level is disappointing at just 0.8 volts and this is totally unloaded (i.e. measuring it like a DAC, not headphone amp). Overall noise was a concern as well so on a hunch, I disconnected the USB cable and situation much improved:
Clearly there is not much filtering going on with respect to noise over USB bus. I guess the Fire 7 will be my ideal target for testing of USB decrapifiers (filters) in the future!
Even at this improved level, we are talking worse performance than countless headphone dongles:
Let's load down the output with 300 ohm to simulate high impedance headphone:
Well, we have even less output. This puts the Fire 7 at the bottom of barrel with respect to available power:
We can already tell the output impedance is high since we saw the above voltage drop even with a light load. So naturally things get a lot worse with a 33 ohm load:
Notice the very high output impedance of 40 ohm which means the frequency response (tonality) of most headphones will change (for good or bad). Distortion has also picked up. Ranking is just as bad as before:
Bummer....
Amazon Fire 7 Listening Test
I played a few tracks from my headphone amplifier playlist with my Sennheiser HD-650 and results were like the measurements said. There is hardly any deep bass to speak of. Volume was barely enough at max setting. On anything recorded below max digital level, there was not enough volume. Overall experience would not be good unless you use a much more sensitive headphone/IEM.
Conclusions
It is an incredible time we are living in when so much technology can be had for just $50! Yes, even with all the advertising and subsidy, this kind of price is hard to fathom. Alas, either engineers didn't care or were not allowed (on cost or space) to include anything better than nearly worst of the worst DAC and headphone amplifier. Such a shame. What is there is good enough for youtube, audiobook listening and such but not for any serious music enjoyment.
Sadly, I can't recommend the Amazon Fire 7 for its built-in audio capabilities. Best to seek out a last generation LG phone or something for that purpose.
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As always, questions, comments, recommendations, etc. are welcome.
Appreciate any donations using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
This is relative small tablet at 7 inch but then again, much larger than any DAP:
Aspect of price subsidy is abundant in constant nagging it does to sign up for various Amazon services. Even though we use Amazon shopping everyday and I don't have an ill opinion of the company, even I was annoyed with so much pushing. They slow down a machine that is already rather slow to operate.
My favorite media player -- Roon -- complained that resolution was too low and wanted to run full screen which I let it. There were a few second pauses at times trying to navigate my playlist and touching seemed to not work at times. Overall though, the large screen and familiar apps is far, far better than anything a DAP has to offer. The main issue then is audio performance so let's measure that.
Amazon Fire 7 Measurements: Audio
I started my testing with USB charging cable plugged into my usual source (the hub in my monitor which is fairly clean):
Output level is disappointing at just 0.8 volts and this is totally unloaded (i.e. measuring it like a DAC, not headphone amp). Overall noise was a concern as well so on a hunch, I disconnected the USB cable and situation much improved:
Clearly there is not much filtering going on with respect to noise over USB bus. I guess the Fire 7 will be my ideal target for testing of USB decrapifiers (filters) in the future!
Even at this improved level, we are talking worse performance than countless headphone dongles:
Let's load down the output with 300 ohm to simulate high impedance headphone:
Well, we have even less output. This puts the Fire 7 at the bottom of barrel with respect to available power:
We can already tell the output impedance is high since we saw the above voltage drop even with a light load. So naturally things get a lot worse with a 33 ohm load:
Notice the very high output impedance of 40 ohm which means the frequency response (tonality) of most headphones will change (for good or bad). Distortion has also picked up. Ranking is just as bad as before:
Bummer....
Amazon Fire 7 Listening Test
I played a few tracks from my headphone amplifier playlist with my Sennheiser HD-650 and results were like the measurements said. There is hardly any deep bass to speak of. Volume was barely enough at max setting. On anything recorded below max digital level, there was not enough volume. Overall experience would not be good unless you use a much more sensitive headphone/IEM.
Conclusions
It is an incredible time we are living in when so much technology can be had for just $50! Yes, even with all the advertising and subsidy, this kind of price is hard to fathom. Alas, either engineers didn't care or were not allowed (on cost or space) to include anything better than nearly worst of the worst DAC and headphone amplifier. Such a shame. What is there is good enough for youtube, audiobook listening and such but not for any serious music enjoyment.
Sadly, I can't recommend the Amazon Fire 7 for its built-in audio capabilities. Best to seek out a last generation LG phone or something for that purpose.
------------
As always, questions, comments, recommendations, etc. are welcome.
Appreciate any donations using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
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