Loxjie A30 Amplifier Review

[Gruesome]

Does anybody know whether the A30 displays clipping and error conditions in the display? The motherboard has test points that expose the power amplifier pins for these signals (right below the row of green 25V caps in the screenshot), so in principle one could add LEDs for them.

 

[Gruesome]

Question: just to confirm, the two negative speaker outputs of the A30 are NOT at ground level, right? So if I wanted to connect a stereo meter/measurement unit, like the Evor04 (https://www.audiosciencereview.com/...emote-digital-vu-spectrum-meter-review.44010/), to the speaker outputs, I would have to go through isolation transformers (and voltage dividers, to bring the 24V max down to about 2V)?
Update: Later confirmed by accident, when I forgot to put the transformer into the path; also confirmed that the A30 protection circuit is working.

 

[alaios]

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/

Two super noob questions. Article refers to 4 and 8 Ohms. Will work also with 6 Ohms speakers?
Does it also have a sub out?

 

[Zek]

Will work also with 6 Ohms speakers?

Yes, of course.

Does it also have a sub out?

Yes.

 

[Dwight]

is it possible to connect the pre out output of the front speakers of a HT amplifier to the RCA inputs of the loxjie?

 

[voodooless]

is it possible to connect the pre out output of the front speakers of a HT amplifier to the RCA inputs of the loxjie?

Yes, that should work just fine, just set the volume control to max. Note however that most AVRs will have more power.

 

[alaios]

So I bought it and I have confirmed that the power unit of the Loxjie really affects the performance of my powerline adapter
That probably means that the power unit emits a lot of noise to the powerline. Any idea what I can do and resolve the issue?

 

[Gruesome]

So I bought it and I have confirmed that the power unit of the Loxjie really affects the performance of my powerline adapter
That probably means that the power unit emits a lot of noise to the powerline. Any idea what I can do and resolve the issue?

An ethernet over powerline adapter?

 

[somebodyelse]

I assume it's ethernet over powerline - to the owner they emit 'signal' onto the powerline, but to nearby radio amateurs they can be quite an intrusive noise source. I suppose it could be something like X10 for home automation though. An inline mains filter to the Loxjie might help, but depending on how it's constructed and where on the 'network' it is it might remove the powerline signal too. The perils for abusing the mains as a data cable, although in some situations the choices are limited.

 

[Gruesome]

Put the A30 and the ethernet adapter onto mains circuits coming from different breakers. That's probably the best you can do. And I assume the ethernet over power works better if the two ethernet adapters are on the same breaker.

 

[BPM]

I have the Dynavoice version (ca802bt.. Here in Sweden can buy it in stores. Under the Loxjie-brand shipping from abroad is the only option) and I am having a hard time believing what I am hearing.. Toslink from TV to the amp that is hooked up to a pair of 3-way Audio Pro Blue Diamond. Big speakers with active 10” woofers under 55Hz but the 6,5” mids and the tweeters are an easy drive for the amp at 91dB/4ohms and it just rocks! Power, clarity, soundstage.. I have a 45m2 living room but this combo gives me all the volume I need and the quality of sound is better with the Dynavoice (Loxjie) than it was with my Onkyo 656 avr. Better clarity, more lifelike voices and a timing, rhytm, that just makes it more interesting to listen to music. The Onkyo suffered a failed hdmi-board and I bought this little thing to keep me going while deciding what new monster to drag home..and I’m glad I did. The Dynavoice will stay in my system.
It’s pretty amazing that this ammount of quality and performance can be had at this price regardless of size.

 

[funkyblue]

I am having a hard time believing what I am hearing.. Toslink from TV to the amp that is hooked up to a pair of 3-way Audio Pro Blue Diamond. Big speakers with active 10” woofers under 55Hz but the 6,5” mids and the tweeters are an easy drive for the amp at 91dB/4ohms and it just rocks! Power, clarity, soundstage.. I have a 45m2 living room but this combo gives me all the volume I need and the quality of sound is better with the Dynavoice (Loxjie)...

Greetings from Australia! I'm excited to share my experience with the Loxjie A30, a purchase I made after extensive research. Pairing the Loxjie A30 with a set of secondhand Q Acoustics 3010 Compact Bookshelf Speakers, I've connected them to my PC to enjoy my extensive FLAC collection through Foobar2000. Let me tell you, it has truly revolutionized my music-listening experience!

In 2003, I relied on an old AKAI stereo that eventually gave out. (Picture 1), Fortunately, I held onto the speakers and switched to a Lepai LP-2020A+ (Picture 2) and a Behringer UCA202 External USB Sound Card DAC (Picture 3), which served me faithfully for years. However, I must admit that upgrading to the Loxjie A30 was a decision I wish I had made much sooner! Pictures are provided to show a bit of history, so why not

 

[Gruesome]

Definitely! The excitement totally shines through.
What's with the pictures though? Are they meant to provide context (rest of your system that fits well with the A30), or contrast (successive upgrades culminating in the A30), or are they maybe for (visual) search engine optimization?

 

[funkyblue]

I added a bit more description. PC to Amp was harder back in the day

 

[Gruesome]

Dang, I thought the item in the third picture was a Walkman! I guess the next (final?) stage after TL;DR is TL;DETTTCLAP (didn't even take time to carefully look at pictures).

 

[krips]

I have one of these on the way, but I see now it has an "analog" and "digital" SINAD. I have a JDS atom dac that I was planning on using instead of the built in one, but if I am understanding this correctly it would somehow perform worse? I'm confused.

 

[Laserjock]

I have one of these on the way, but I see now it has an "analog" and "digital" SINAD. I have a JDS atom dac that I was planning on using instead of the built in one, but if I am understanding this correctly it would somehow perform worse? I'm confused.

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

Check the edit

 

[Ismapics]

2.5 Update
The Loxjie A30 continues to shine. It is at my computer desk, fed by my Mac Mini. I can tell you that it pumps good enough volume for near and mid field listening. Connected to a Sub and Elacs 6.2. Can't complain.

 

[mARCELOCM]

Modded Loxjie A30



I’ve changed the coupling capacitors from my unit, it shipped originaly with 22uf 35v Muse capacitors between the NJW1194 and MA12070, i put metal film polyester 1uf, that config puts the unit in low gain mode.

The Next was the output coupling capacitor, ir shipped with 3300uf eletrolytics, i ordered some solid types with 1000uf, the maximum capacitie i found on internet, but datasheet recommends 470uf, so its enough, the fact with this is it has much faster transient response and quicker charge and discharge habilitie so more fidelitie on speakers

The final result was awesome on ears, i cant believe how good the change was, feels like im wearing headphones now.

For who wanna try this mod, believe me, you Will not be disapointed .

 

[Laserjock]

Modded Loxjie A30



I’ve changed the coupling capacitors from my unit, it shipped originaly with 22uf 35v Muse capacitors between the NJW1194 and MA12070, i put metal film polyester 1uf, that config puts the unit in low gain mode.

The Next was the output coupling capacitor, ir shipped with 3300uf eletrolytics, i ordered some solid types with 1000uf, the maximum capacitie i found on internet, but datasheet recommends 470uf, so its enough, the fact with this is it has much faster transient response and quicker charge and discharge habilitie so more fidelitie on speakers

The final result was awesome on ears, i cant believe how good the change was, feels like im wearing headphones now.

For who wanna try this mod, believe me, you Will not be disapointed .

Send it for for test to @amirm