This is a review and detailed measurements of the JCALLY JM20 USB-C headphone adapter (DAC and Amp). It is on kind loan from a member and is on sale for US $24.
Not much to say about the construction so let's get into measurements. Speaking of that, I finally have a fix for this class of device that allows me to perform full set of measurements like a desktop DAC.
JCALLY JM20 Measurements
Let's start with max volume driving 600 ohm load:
The CS43131 implementation here delivers excellent, desktop-class performance:
Noise performance is impressive:
Distortion is kept at a minimum as well:
I am used to seeing spurious tones in our jitter test but no sign of one here:
Linearity is also excellent except for a bit of deviation as levels get higher:
Standard filter is used:
Wideband distortion+noise vs frequency shows elevated response:
This is due to the DAC pushing the noise from audible band into ultrasonic above 50 kHz. Hence the reason when I limit bandwidth to half as much (green/brown lines), we get the excellent response we expect. Here is the spectrum showing the same:
The 2 volt maximum output (as seen in dashboard) is better than devices that produce half as much, but can't keep up with those with balanced, 4 volt out:
Good current ability means better response into 32 ohm:
Conclusions
[Excellent] desktop class DAC performance with a good enough headphone output for $24. Really, what else would you be asking for?
I am happy to recommend the JCALLY JM20 headphone adapter.
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As always, questions, comments, recommendations, etc. are welcome.
Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
Not much to say about the construction so let's get into measurements. Speaking of that, I finally have a fix for this class of device that allows me to perform full set of measurements like a desktop DAC.
JCALLY JM20 Measurements
Let's start with max volume driving 600 ohm load:
The CS43131 implementation here delivers excellent, desktop-class performance:
Noise performance is impressive:
Distortion is kept at a minimum as well:
I am used to seeing spurious tones in our jitter test but no sign of one here:
Linearity is also excellent except for a bit of deviation as levels get higher:
Standard filter is used:
Wideband distortion+noise vs frequency shows elevated response:
This is due to the DAC pushing the noise from audible band into ultrasonic above 50 kHz. Hence the reason when I limit bandwidth to half as much (green/brown lines), we get the excellent response we expect. Here is the spectrum showing the same:
The 2 volt maximum output (as seen in dashboard) is better than devices that produce half as much, but can't keep up with those with balanced, 4 volt out:
Good current ability means better response into 32 ohm:
Conclusions
[Excellent] desktop class DAC performance with a good enough headphone output for $24. Really, what else would you be asking for?
I am happy to recommend the JCALLY JM20 headphone adapter.
------------
As always, questions, comments, recommendations, etc. are welcome.
Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
Last edited:
……and shame to the ones on the right of the ranking chart.
