This is a review and detailed measurements of the multifunction Loxjie A30 power (speaker and headphone) amplifier with integrated USB DAC and Bluetooth input. It was kindly sent to me by a member and costs US $159 plus $7 shipping on Amazon.
The A30 sports a high resolution and high contrast LCD display which I liked:
I wish that they would highlight the volume in big letters though rather than the input:
A customized remote control comes with as well as a rather massive "laptop" power supply:
The A30 was nice to use and look at.
The A30 is based on Infineon MERUS™ MA12070P Digital filter-less Class-D Audio Amplifier which is a departure from many other desktop amplifiers we have tested. So it will be interesting to see how it performs.
Loxjie A30 Measurements: Amplifier
Because we have both analog inputs and digital, we need to look at the performance of both. Here is analog:
The noise floor is rather high. If we switch to digital input, that reduces substantially as well as distortion:
This is above average performance for any amplifier yet alone a "chip amp" in a small enclosure:
EDIT: Using the same volume level as digital and turning down the input way up, we get the same results as digital input:
Thinking the analog input is digitized, I was surprised that it had such a wide bandwidth:
So not sure what is causing the much degraded performance with analog. The wide bandwidth is also unusual in class D amplifiers which roll off quickly to get rid of switching noise. Eliminating the use of output filter helps to widen the bandwidth quite a bit.
Using Toslink input, we see very good signal to noise ratio as we would predict:
Many high performance amps struggle to clear the 16 bit hurdle at 16 bits but the A3 gets there with ease.
Crosstalk using digital input is superb:
Let's see what our power vs distortion curve looks like starting with 4 ohm load and analog input:
We get an honest 40 watts with both channels driven which is very nice for a tiny, very cool running amp. Noise though varies up and down so let's switch to digital input again:
Notice how the A30 is tracking the performance of "high-end" Arcam AVR10!
Due to use of regulated switching power supply and strict protection circuit, there was not more power to be had in burst or higher distortion:
Switching to 8 ohm we get:
Once again noise and distortion are under control until we run out of power.
Loxjie A30 Measurement: Headphone Amplifier
Let's cut the chase and measure power vs distortion at 300 ohm and 33 ohm:
Very poor. If you need to hear sound you can use it otherwise, you should get a proper high performance headphone amplifier.
Loxjie A30 Listening Tests
I decided to test the A30 in a typical desktop setup. So I grabbed the PSB Alpha P5 (84 dB sensitivity) and connected it to the A30. I was most impressed with power ability and lack of distortion! There was incredible bass and ability to drive the P5 hard. And loud. I could get ample loudness while staying below 50 on the volume control. Playing my deep bass tracks however caused distortion to show up above 50 (mild crackling). But really, that was quite hard and we are talking using just one speaker here.
Overall experience below limit was absolutely audiophile with no excuses to be made.
Conclusions
The performance of desktop power amplifiers has been disappointing. Often the power is very low and distortion and noise quite high. Until now, I have not had any that I would recommend strongly. Well all that changed with the Loxjie A30. This is an attractive, solid performance with excellent measured and subjective sound quality. Inclusion of a USB DAC and Coax/Toslink input eliminates the need for a DAC for less clutter. It can easily replace a sound bar (using Toslink input from TV) and make for a great secondary system. 40 watts into 4 ohm with very low distortion and noise is plenty good for desktop use.
Testing the Loxjie A30 put a smile on my face and landed it happily on my recommended list. You are getting restaurant quality meal at fast food prices.
------------
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/
The A30 sports a high resolution and high contrast LCD display which I liked:
I wish that they would highlight the volume in big letters though rather than the input:
A customized remote control comes with as well as a rather massive "laptop" power supply:
The A30 was nice to use and look at.
The A30 is based on Infineon MERUS™ MA12070P Digital filter-less Class-D Audio Amplifier which is a departure from many other desktop amplifiers we have tested. So it will be interesting to see how it performs.
Loxjie A30 Measurements: Amplifier
Because we have both analog inputs and digital, we need to look at the performance of both. Here is analog:
The noise floor is rather high. If we switch to digital input, that reduces substantially as well as distortion:
This is above average performance for any amplifier yet alone a "chip amp" in a small enclosure:
EDIT: Using the same volume level as digital and turning down the input way up, we get the same results as digital input:
Thinking the analog input is digitized, I was surprised that it had such a wide bandwidth:
So not sure what is causing the much degraded performance with analog. The wide bandwidth is also unusual in class D amplifiers which roll off quickly to get rid of switching noise. Eliminating the use of output filter helps to widen the bandwidth quite a bit.
Using Toslink input, we see very good signal to noise ratio as we would predict:
Many high performance amps struggle to clear the 16 bit hurdle at 16 bits but the A3 gets there with ease.
Crosstalk using digital input is superb:
Let's see what our power vs distortion curve looks like starting with 4 ohm load and analog input:
We get an honest 40 watts with both channels driven which is very nice for a tiny, very cool running amp. Noise though varies up and down so let's switch to digital input again:
Notice how the A30 is tracking the performance of "high-end" Arcam AVR10!
Due to use of regulated switching power supply and strict protection circuit, there was not more power to be had in burst or higher distortion:
Switching to 8 ohm we get:
Once again noise and distortion are under control until we run out of power.
Loxjie A30 Measurement: Headphone Amplifier
Let's cut the chase and measure power vs distortion at 300 ohm and 33 ohm:
Very poor. If you need to hear sound you can use it otherwise, you should get a proper high performance headphone amplifier.
Loxjie A30 Listening Tests
I decided to test the A30 in a typical desktop setup. So I grabbed the PSB Alpha P5 (84 dB sensitivity) and connected it to the A30. I was most impressed with power ability and lack of distortion! There was incredible bass and ability to drive the P5 hard. And loud. I could get ample loudness while staying below 50 on the volume control. Playing my deep bass tracks however caused distortion to show up above 50 (mild crackling). But really, that was quite hard and we are talking using just one speaker here.
Overall experience below limit was absolutely audiophile with no excuses to be made.
Conclusions
The performance of desktop power amplifiers has been disappointing. Often the power is very low and distortion and noise quite high. Until now, I have not had any that I would recommend strongly. Well all that changed with the Loxjie A30. This is an attractive, solid performance with excellent measured and subjective sound quality. Inclusion of a USB DAC and Coax/Toslink input eliminates the need for a DAC for less clutter. It can easily replace a sound bar (using Toslink input from TV) and make for a great secondary system. 40 watts into 4 ohm with very low distortion and noise is plenty good for desktop use.
Testing the Loxjie A30 put a smile on my face and landed it happily on my recommended list. You are getting restaurant quality meal at fast food prices.
------------
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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