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Loxjie A30 Amplifier Review

amirm

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#1
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:

Loxjie A30 Amplifier review.jpg


I wish that they would highlight the volume in big letters though rather than the input:
Loxjie A30 Amplifier review Display.jpg


A customized remote control comes with as well as a rather massive "laptop" power supply:

Loxjie A30 Amplifier review Power Supply Bluetooth DAC.jpg


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:

Loxjie A30 Amplifier Measurements Analog Input.png


The noise floor is rather high. If we switch to digital input, that reduces substantially as well as distortion:
Loxjie A30 Amplifier Measurements Toslink Input.png


This is above average performance for any amplifier yet alone a "chip amp" in a small enclosure:

Best desktop budget amplifier.png


EDIT: Using the same volume level as digital and turning down the input way up, we get the same results as digital input:

Loxjie A30 Amplifier Measurements Analog Input High.png


Thinking the analog input is digitized, I was surprised that it had such a wide bandwidth:
Loxjie A30 Amplifier Frequency Response Measurements Analog Input.png


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:

Loxjie A30 Amplifier SNR Measurements Toslink Input.png


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:
Loxjie A30 Amplifier Crosstalk Measurements Toslink Input.png


Let's see what our power vs distortion curve looks like starting with 4 ohm load and analog input:

Loxjie A30 Amplifier Power into 4 ohm Measurements Analog Input.png


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:

Loxjie A30 Amplifier Power into 4 ohm Measurements Toslink Input.png


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:

Loxjie A30 Amplifier Max and Peak Power into 4 ohm Measurements Analog Input.png


Switching to 8 ohm we get:

Loxjie A30 Amplifier Power into 8 ohm Measurements Toslink Input.png


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:

Loxjie A30 Amplifier Headphone Output 300 ohm Measurements Analog Input.png


Loxjie A30 Amplifier Headphone Output 33 ohm Measurements Analog Input.png


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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sweetchaos

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pjug

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#6
Is it too late to see switching noise? Can this infineon technology really run without output filtering at these power levels or does this device have output filtering?
 

infinitesymphony

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#8
I'm on the lookout for a tiny speaker amp like this one, but it's a shame about the analog performance. Still hoping for something with Yamaha WXA-50 performance and Topping MX3 price. Wonder where the Topping PA3 would slot in.
 
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amirm

amirm

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bunkbail

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#12
Why on earth would you grab the PSB alphas? There are people who care about you Amir!
True dat. I was hoping he tried it with Wharfedale Diamonds instead, would make a nice combo for a budget PC setup.
 
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amirm

amirm

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Thread Starter #13
Why on earth would you grab the PSB alphas?
It was the first speaker I saw in a large stack next to me. Actually I saw my Revels first but out of abundance of caution, I did not want to subject them to testing just in case the amp distorted too much. :)
 

Cahudson42

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#15
Ok.. $160.. Maybe I am not seeing this correctly - when I see:
- a DAC performance easily matched by many dongles
- a poor (useless?) headphone amp
- better Lepy-type power amp

So - for $9 we can get a better performing Apple DAC and what seems a no-worse 30mw HP amp to boot;

For $150 what most likely is a better performing bt speaker Amp:
https://www.crutchfield.com/p_022RS202/Yamaha-R-S202.html

Seems an easy choice to me...
 

Matias

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#16
@amirm Could you please measure distortion over frequency to see if it is well behaved on high frequencies?
 
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amirm

amirm

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amirm

amirm

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Thread Starter #18
So - for $9 we can get a better performing Apple DAC and what seems a no-worse 30mw HP amp to boot;
There is no remote, or volume control on that dongle. And no display.
 
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amirm

amirm

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