Loxjie A30 Amplifier Review

[Steve.]

I do not see your problem. Do you not like USB? Converting USB to TOSLINK does not improve quality anywhere. It removes the host's ability to get feedback from the DAC. The iPad would not know what it was talking to is you ran to a switch.

It's that currently on the Loxjie A30 some of the posters above have seen that the USB input bypasses the ESS Sabre DAC and instead relies on the Realtek DAC which is currently a mystery.

Are you familiar with the XMOS USB chip? that's what's being used in the Douk Audio USB > Toslink converter. The idea here is that converter would help pass the data to the ESS chip in the Loxjie - it is very specific to this usecase. I really don't love the idea of doing it all but am looking into it.

 

[TheElementOfSurprise]

I do not see your problem. Do you not like USB? Converting USB to TOSLINK does not improve quality anywhere. It removes the host's ability to get feedback from the DAC. The iPad would not know what it was talking to is you ran to a switch.

DDCs can correct the timings from a noisy source, namely a PC with lots of other electronics nearby. Whether the improvement is audible is another debate:

 

[tvrgeek]

All I know about the XMOS chip is it is ubiquitous. Schiit says they can do better, but JDS says it is all implementation. I think some want to not be so reliant on dedicated sole source parts and are looking to FPLAs which are more generic.

I do not know the Loxie at all, but it does not make sense to me it would have two different DACs. Sounds expensive for no reason. I will say, the D30pro was an superb sounding unit. I only returned it for a driver compatibility issue. Listening to an Atom DAC+ right now. Impressed. It has only two inputs and of course, no volume control as it is a DAC, not DAC/pre.

 

[funkyblue]

I don't know what the issue is? It's a great all in one device that sounds amazing. I have mine connected to PC via USB and sometimes Bluetooth from my phone.

 

[tvrgeek]

DDCs can correct the timings from a noisy source, namely a PC with lots of other electronics nearby. Whether the improvement is audible is another debate:

Video does explain why to use USB and not Toslink. I do not know for sure if he is correct that PCM/Toslink is not re-clocked by the DAC in all boxes. That would explain why some measure different with different inputs, and some measure the same.

Now, I have on hand, a $16 cheap Chinese USB galvanic isolator and a Linear Tech high end instrumentation isolator I bought for my digital scope. I plan on benching them with my music server (low end all-in-one) and antique laptop to see if either has any issue and if any of that actually makes it into the output with any of my DACs. My first test with a Focusrite showed zero difference, so whatever it may be, it was below -130 so I don't care.

A curious note. The Atom came with a USB cable with a choke on it. Two turns. So they have some reason to think the cable shield can pick up some RF. I will use their cable. And that gives me something to compare, though I don't think my house is a very "noisey" environment. Some of the reviewers desks must be horrendous.

 

[Steve.]

Just want to level set here and say that the point of my earlier post is specific to the Loxjie A30's implementation of USB being potentially inferior than its Toslink input, as the USB input potentially does not use the Sabre DAC but an unknown DAC baked into the Realtek chip that handles the USB input. Appreciate everyone's thoughts on general USBness tho.

 

[JulienV]

Hi guys, if I connect for instance my laptop (Lenovo legion y540) via its coaxial 3,5mm Jack port to the Jack port of this amplifier, well this last one will receive an analog signal as my PC has an integrated DAC from what I've understood.
I guess if the DAC of the amp is better than the one of my computer, the amp's DAC will make the analog signal smoother/better, right?

Question am asking myself too is if using the USB port of my PC, so digital signal from what I read, with the micro one of the amp would sound better?
I've read different opinions in the forum about this and thought maybe someone did a technical analysis eventually

 

[aktiondan]

@Steve. based on the trace routing of the PCB, the ES9023 DAC is not used to decode anything coming off of USB. Which at first I too thought was crazy, because I thought they should have designed it that way. Note that when you select USB it simply reports CONNECTED instead of providing a sample rate. The sample rate is decoded in the ESS DAC and reports out the microprocessor (I think), so only devices that use that DAC report anything with respect to sample rates. Which in this case is Toslink, Coax and BT. Notice BT is also just fixed at 48kHz which is the sample rate between the QCC30xx and the DAC, not the sample rate of the BT transmission (so no matter what you select on your phone, the display doesn't change, this is probably why). I'm guessing if they had opted to run I2S to the DAC, it could have reported up to the full 384kHz, what the Realtek codec can sample at. Except wouldn't you know that the ES9023 can only handle sample rates up to 200 kHz! So that's most likely why they opted to use their own internal DAC, the ESS DAC would have actually handicapped the available sample rate provided by the Realtek codec. You win some you lose some I suppose.

I personally wouldn't stress the specs on the Realtek DAC, it's not like the ESS DAC is state of the art here. Maybe it's better? Not much out there online about it. I attempted to measure something meaningful on the USB side of things but was unsuccessful. If you're willing to trust your ears, you could try the USB->Toslink->Sabre route and report if you can hear any differences. Or if you have the means to measure it. I'd be curious as well. My computer has S/PDIF out (via a Realtek ALC892 codec), which is what I am currently using but sadly am running Win8 so USB doesn't work with the A30, so I can't compare them directly/easily.

 

[chunky_lafunga]

I ran into a very troubling issue with my A30 yesterday:

I received a brand new A30 and connected it to my laptop via USB.

I decided to play Spotify on my laptop through connected headphones, to 'break them in' (at 30 volume) and walked away from my computer into living room. After about 20-30 mins, I could hear a very high pitch whine - I couldn't figure out what it was, thought it was my washing machine cycle filling up with water (it makes a similar sound when you can hear it from the living room).

After a while I got up as the sound was continuing. Walked into my study where my laptop is and lo and behold, my headphones were blasting this terrible white/brown noise (and at 30 volume)! I immediately switched output to speaker and the same noise was being output through my speakers. I quickly closed Spotify wondering what the hell that noise was! Surely I thought it would have damaged my headphones - it was that loud and that bad.

I went straight to Youtube (on the laptop, with headphones still connected to A3o) to test of the issue was the source - and the terrible sound continued even on Youtube.

Next I cycled through the different inputs (Optical, BT, AUX etc) until I got back to USB. played music again and now it was perfectly fine and back to normal.

Has anyone experienced this? This is EXTREMELY shocking to me. If I had those headphones on my ears, I no doubt would have busted my eardrums - the sound was that intense and piercing that I could hear it 30ft away in my living room. I messaged Loxjie on AliExp and he said this:

"Hello, we have received your feedback that white noise may be caused by:
1. It may be a device compatibility problem, just restart
2. Because the bit rate of the played song is too high, it exceeds the decoding capacity of A30. Don't play songs over 384khz."

But the thing is, I was playing through Spotify with audio quality set to 'Very High", which I understand is only 320kbps. Or am I not understanding correctly? How many khz does 320kbps convert to? Sorry for the dumb questions. Just very annoyed at what just happened.

@kniff @ctakim I read through this thread and noticed you both had somewhat similar issues. Did you ever figure out the problem?

 

[The Capstan]

I ran into a very troubling issue with my A30 yesterday:

How many khz does 320kbps convert to? Sorry for the dumb questions. Just very annoyed at what just happened.

@kniff @ctakim I read through this thread and noticed you both had somewhat similar issues. Did you ever figure out the problem?

320kbps has nothing to do with sampling rate. This is the bit rate of the compressed stream. The BT interface in the A30 converts at a fixed 48KHz *sample* rate.
I am using my A30 connected via optical input (chain is MacMini with Daphile installed -> optical to Behringer DEQ2496 for room correction -> optical to Loxjie A30 -> output to KEF LS50 + Dynaudio Sub (via Loxjie sub output).

In more than one year time I have never run in a similar issue.

It looks more a compatibility issue with your USB laptop interface. What laptop/OS are you using? Have you the latest usb drivers installed?

my 2 cents.
alessandro

 

[chunky_lafunga]

320kbps has nothing to do with sampling rate. This is the bit rate of the compressed stream. The BT interface in the A30 converts at a fixed 48KHz *sample* rate.
I am using my A30 connected via optical input (chain is MacMini with Daphile installed -> optical to Behringer DEQ2496 for room correction -> optical to Loxjie A30 -> output to KEF LS50 + Dynaudio Sub (via Loxjie sub output).

In more than one year time I have never run in a similar issue.

It looks more a compatibility issue with your USB laptop interface. What laptop/OS are you using? Have you the latest usb drivers installed?

my 2 cents.
alessandro

Lenovo Thinkpad T480 (Windows 10) --(Thunderbolt 4 cable)--> Caldigit TS3plus Thunderbolt 3 dock --(USB)--> Loxjie A30 --(12awg speaker cable)--> Neumi BS5

The above is exactly how I used my Topping MX3. So all I've done is swap out the MX3 with the A30 (and corresponding power adaptor).

Should I try optical between the Caldigit dock and the A30? Something like this - https://www.amazon.sg/gp/product/B01NAUN6YB/ref=ox_sc_act_title_1?smid=ARPIJN329XQ0D&psc=1?

EDIT:

I found a spore Toslink Optical and plugged it in. Question, should I be changing any of these settings on my Windows 10 laptop now that I'm using optical?

(48 khz is what it was set at by default)

(2 channel, 24 bit, 48 kHz is what it was set at by default)

 

[Hapo]

...I was discouraged to see the A30 is now $259.99...is it worth the extra $100...???...

...I want something very compact and clean to drive a set of Energy 2.1e's...

...I had been running them on a Dayton APA150 but am using that amp to run my new ELAC UniFi 2.0's...

...I really liked that amp until I logged on here and read amirm's review...LoL...

...how would such an amp run the inefficient ELAC speakers...???...the APA 150 drives them to acceptable levels and then some...

...I was all in @ $160 but @ $260 it gives me pause...I could have another APA 150 for less than that...

 

[funkyblue]

I'd get this instead: Topping DX3 Pro+

$199

TOPPING DX3 Pro+ ES9038Q2M Desktop DAC & Headphone Amplifier

Product Highlights: Four output modes: Headphone Amp, Headphone Amp+Line out, DAC, and Pre-amplifier. QCC5125 chipset, supports LDACIAAC/SBCIAPTXIAPTX LL/APTX HD protocol 2nd generation 8 core XMOS XU208, USB input supports up to PCM32bit768kHz and DSD512 native Optimized NFCA circuit, with...

shenzhenaudio.com

 

[Laserjock]

I'd get this instead: Topping DX3 Pro+

$199

TOPPING DX3 Pro+ ES9038Q2M Desktop DAC & Headphone Amplifier

Product Highlights: Four output modes: Headphone Amp, Headphone Amp+Line out, DAC, and Pre-amplifier. QCC5125 chipset, supports LDACIAAC/SBCIAPTXIAPTX LL/APTX HD protocol 2nd generation 8 core XMOS XU208, USB input supports up to PCM32bit768kHz and DSD512 native Optimized NFCA circuit, with...

shenzhenaudio.com

Not a speaker amplifier?

 

[funkyblue]

Not a speaker amplifier?

Ohh I thought it was? Is it not similar to the Loxjie A30?

 

[Laserjock]

Ohh I thought it was? Is it not similar to the Loxjie A30?

No, it’s a DAC/HP Amp

 

[Hapo]

...now I see the 'A30 @ $185.99 @ Amazon but I also see the Aiyima D 03 @ $159.99 so I am still conflicted ...

 

[chunky_lafunga]

Lenovo Thinkpad T480 (Windows 10) --(Thunderbolt 4 cable)--> Caldigit TS3plus Thunderbolt 3 dock --(USB)--> Loxjie A30 --(12awg speaker cable)--> Neumi BS5

The above is exactly how I used my Topping MX3. So all I've done is swap out the MX3 with the A30 (and corresponding power adaptor).

Should I try optical between the Caldigit dock and the A30? Something like this - https://www.amazon.sg/gp/product/B01NAUN6YB/ref=ox_sc_act_title_1?smid=ARPIJN329XQ0D&psc=1?

EDIT:

I found a spore Toslink Optical and plugged it in. Question, should I be changing any of these settings on my Windows 10 laptop now that I'm using optical?

View attachment 178167
(48 khz is what it was set at by default)


View attachment 178168
(2 channel, 24 bit, 48 kHz is what it was set at by default)

Forgot to mention; when switching input from USB to Optical on the remote (I have both connected right now for easy switching), there is a volume increase when switching over to the Optical input. I would say 2db. Is that expected behaviour?

 

[Waloshin]

At the beginning of this song the Loxjie A30 can barley hear the rain I need to be at 25 to hear.

I am sure on my previous amp I could hear this even at a low volume.

 

[antcollinet]

Hi guys, if I connect for instance my laptop (Lenovo legion y540) via its coaxial 3,5mm Jack port to the Jack port of this amplifier, well this last one will receive an analog signal as my PC has an integrated DAC from what I've understood.
I guess if the DAC of the amp is better than the one of my computer, the amp's DAC will make the analog signal smoother/better, right?

Question am asking myself too is if using the USB port of my PC, so digital signal from what I read, with the micro one of the amp would sound better?
I've read different opinions in the forum about this and thought maybe someone did a technical analysis eventually

No, if you put an analogue input into the amp, the dac in the amp is not needed or used. (DAC is digital to analogue converter)

You will get better results driving the amp from a digital source - such as the USB output of your computer. Whether you are able to hear the difference is another matter.