Loxjie A30 Amplifier Review

[kandamrgam]

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:

View attachment 93584

I wish that they would highlight the volume in big letters though rather than the input:
View attachment 93585

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

View attachment 93586

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:

View attachment 93588

The noise floor is rather high. If we switch to digital input, that reduces substantially as well as distortion:
View attachment 93589

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

View attachment 93590

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

View attachment 93648

Thinking the analog input is digitized, I was surprised that it had such a wide bandwidth:
View attachment 93591

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:

View attachment 93592

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:
View attachment 93593

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

View attachment 93594

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:

View attachment 93595

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:

View attachment 93596

Switching to 8 ohm we get:

View attachment 93597

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:

View attachment 93598

View attachment 93599

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/

A30 seem to be using MA12070, not MA12070P as this post suggests. Or they changed recently. See the internal shot: https://ae01.alicdn.com/kf/Hdaf0433b8faf4284abb00fc7c5ced70e7.jpg

MA12070P receives digital input and MA12070 receives analog input.

 

[eou4]

I solved the problem of occasional sound cutouts when connected to the optical output of my LG TV.
The external HDMI input no longer has the problem, but when watching TV with an antenna, the sound still occasionally cuts out (though much improved).
Here's the solution: Detach the DAC's MCLK pin from the PCB and connect a 50MHz oscillator to it.
This requires soldering skills and requires connecting the digital power supply to the oscillator. Each A30 has a slightly different circuit, so you'll need to find it yourself. The easiest location is probably a capacitor on a nearby chip or the power supply of the Bluetooth module.

 

[ThsM]

Quick question on how to interpret that statement of the review, "The noise floor is rather high. If we switch to digital input, that reduces substantially as well as distortion:"

Do I get this correctly, that I should rather use the digital input, in my case USB, to connect the A30 to my laptop/PC, than connecting my Topping E30's analog out? As the ranking on the graph is also much better with the digital input. But the Conclusions does not state that one should rather use digital inputs.

TLDR
Should I rather connect my A30 via USB/SPIDIF to my Laptop/PC, or would a DAC like the Topping E30 improve the sound quality.

 

[somebodyelse]

Quick question on how to interpret that statement of the review, "The noise floor is rather high. If we switch to digital input, that reduces substantially as well as distortion:"

Do I get this correctly, that I should rather use the digital input, in my case USB, to connect the A30 to my laptop/PC, than connecting my Topping E30's analog out? As the ranking on the graph is also much better with the digital input. But the Conclusions does not state that one should rather use digital inputs.

TLDR
Should I rather connect my A30 via USB/SPIDIF to my Laptop/PC, or would a DAC like the Topping E30 improve the sound quality.

You missed this bit further down:

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

So the difference was caused by the volume level not the source, and it won't make a significant difference which you use as the input because the internal DAC isn't the weak link.

 

[ThsM]

You missed this bit further down:

So the difference was caused by the volume level not the source, and it won't make a significant difference which you use as the input because the internal DAC isn't the weak link.

Thank you very much for the clarification.

Btw. how does the A30 fare in terms of sound quality compared to the newer amps discussed/hyped(?) here recently. Like Douk Audio A5, Fosi ZA3 or the very new Aiyima A20. Would these newer amps get me a noticeable upgrade in sound quality (like detail retrieval or clarity) in a desktop setup with something like the Q Acoustics 3010c or Klipsch RP 500 MK2.

 

[Ismapics]

Thank you very much for the clarification.

Btw. how does the A30 fare in terms of sound quality compared to the newer amps discussed/hyped(?) here recently. Like Douk Audio A5, Fosi ZA3 or the very new Aiyima A20. Would these newer amps get me a noticeable upgrade in sound quality (like detail retrieval or clarity) in a desktop setup with something like the Q Acoustics 3010c or Klipsch RP 500 MK2.

I have one of the early copies, maybe second production batch. Connected through USB so far I have no complaints other than when I recently upgraded my speakers, the amp struggles to make volume. Still sounds good, its just that the Elac DBR-62 need much more power to make volume I need once in a while.

 

[antcollinet]

Btw. how does the A30 fare in terms of sound quality compared to the newer amps discussed/hyped(?) here recently.

Unlikely that you will hear a difference - if you can reach the volume you want without clipping.

 

[ThsM]

Unlikely that you will hear a difference - if you can reach the volume you want without clipping.

For my small room, desktop setup, the volume was/is no issue.

Sonically and feature wise, there is no actual need for a new amp. I just read all that praise for these new amps and it felt I am missing out that great sound they seem to produce.

 

[redscreen]

Hello.
I just bought this LOXJIE A30 and now need to connect it to my PC via USB.
Do I need a USB 2 or USB 3 cable ?
And what is the maximum length ?

Also the bluetooth doesn't work with me TV Philips 58PUS8545, what to do ?

Thank you.

 

[Timcognito]

Hello.
I just bought this LOXJIE A30 and now need to connect it to my PC via USB.
Do I need a USB 2 or USB 3 cable ?
And what is the maximum length ?

Also the bluetooth doesn't work with me TV Philips 58PUS8545, what to do ?

Thank you.

USB cable can be very long get the latest. Bought this for my son a few years ago. From memory, most issues were resolved by using the menus in the software. You have enable everything every time you use it with those menus but once you do it a couple times its second nature with the remote.

LOXJIE-A30-Manual.pdf

drive.google.com

 

[redscreen]

USB cable can be very long get the latest

LOXJIE-A30-Manual.pdf

drive.google.com

Thanks for your reply and the manual.
I need ~10 meters, so it's great if that's not a problem.
I've already read the manual, but it doesn't mention whether I need a USB 2 or USB 3 cable.
So I'll buy a 10-meter USB 2 cable.

 

[voodooless]

I need ~10 meters, so it's great if that's not a problem.

That is potentially a problem. USB 2.0 is speced upto 5 meters, so anything above can be hit and miss.

If you really want to use a longer cable, use one of those active cables that use fiber(or similar) to transport the data. Those are significantly more expensive, though.

 

[somebodyelse]

That is potentially a problem. USB 2.0 is speced upto 5 meters, so anything above can be hit and miss.

If you really want to use a longer cable, use one of those active cables that use fiber(or similar) to transport the data. Those are significantly more expensive, though.

Or use a hub between 2 decent 5m cables