Loxjie A30 Amplifier Review

[waKaka]

数字输入包括 USB、同轴和光纤 (S/PDIF)。根据一些人（包括我）的说法，USB 输入不如同轴和光纤输入。

many thanks sir

 

[BDWoody]

Digital inputs include USB, coaxial and optical (S/PDIF). According to some (including me), the USB input is inferior to the coaxial and optical inputs.

In what way?

 

[Zek]

I noticed that loxjie d30 has coaxial. Is it a digital input? Does the test result of d30 digital input include coaxial？

Did you mix up the A30 with the D30? This is a thread about the A30.

 

[davkj]

What are A30 users using to connect speakers to the tiny binding posts? Most bananas I've tried are too long or don't grip since the post is so short. Spades are tough since there is not much room around the sides of the posts. Just using bare wire? Any bananas that work? Thanks.

 

[lfallon86]

What are A30 users using to connect speakers to the tiny binding posts? Most bananas I've tried are too long or don't grip since the post is so short. Spades are tough since there is not much room around the sides of the posts. Just using bare wire? Any bananas that work? Thanks.

Using bananas over here & length was fine with these (https://www.amazon.com/dp/B0029XW5JA?ref=ppx_yo2ov_dt_b_product_details&th=1) ... it seems to fit "snugger" on the speaker side, but these bananas still fit securely in the a30 & aren't going anywhere.

 

[ClassicGuy]

Well, cable appeared in securely - but decided to take out / put back in to be sure .. Sure enough, I haven't had any cutouts since (had it playing for a few hours, including same content which was sporadically cutting out last night). Anyway, thank you sir - sometimes it's literally the ol' "have you tried unplugging & plugging back in?" solution lol.

Glad it worked for you. I believe I had a similar experience when I started using optical cables on a different device. It's not always obvious whether the cable is fully seated or not. Also, some cables come with covers on both ends that are meant to be taken off before usage.

 

[Dystophic]

In what way?

I assume you mean the USB contra Coax/SPDIF? Earlier in the thread, someone noted that the UBS input was routed through a Realtek chip rather than the superiour Sabre DAC used for coax / SPDIF. Another user tried to put a Douk Audio U2 between the computer and the Loxjie and noted a better sound. That made me curious and I tried to do the same, and I noted that - especially for music - the sound quality improved quite a bit, the best way to describe it is a larger sound stage and overall better sound. Whether this is placebo or actually measurable is not for me to decide!

 

[BDWoody]

I tried to do the same, and I noted that - especially for music - the sound quality improved quite a bit, the best way to describe it is a larger sound stage and overall better sound. Whether this is placebo or actually measurable is not for me to decide!

Who else is going to do it?

Here's a video that can help get you started:

 

[ClassicGuy]

I don't have good USB sources so haven't tried the USB connection in depth. I have been using both the optical and aux inputs, and personally I feel the optical is a bit better than the aux input for the Loxjie, even compensating for the volume difference.

 

[Dystophic]

I have been using both the optical and aux inputs

Aux (line in?) is analog, it bypasses the DAC in the Loxjie and only uses the amp - comparing aux and digital / optical makes little sense in that matter.

 

[antcollinet]

Aux (line in?) is analog, it bypasses the DAC in the Loxjie and only uses the amp - comparing aux and digital / optical makes little sense in that matter.

Worse - the loxjie is a digital amp - no dac as such. Digital signals are processed to drive the PWM to the speakers directly with no analogue signal created (except directly on the output speaker posts).

The analogue input must first be digitised with an ADC before it can be amplified.

Looks like I got this wrong. I must have mixed up the A30 with another amp somewhere. This one is not fully digital, sorry for the misinformation. (See post below by @The Capstan )

 

[ClassicGuy]

Worse - the loxjie is a digital amp - no dac as such. Digital signals are processed to drive the PWM to the speakers directly with no analogue signal created (except directly on the output speaker posts).

The analogue input must first be digitised with an ADC before it can be amplified.

Interesting. Yeah, what I was trying to say was that the aux input seems somewhat degraded, this would explain why.

 

[antcollinet]

Interesting. Yeah, what I was trying to say was that the aux input seems somewhat degraded, this would explain why.

Its also going to depend on the quality of the analogue source.

 

[ClassicGuy]

Its also going to depend on the quality of the analogue source.

Yes. The reason I brought it up is that my other amps don't have the same issue when fed the same analog source.

 

[Laserjock]

The edit for analog input shows same performance if analog input volume is increased?

The chart hasn’t been updated though. Wondering how this would effect using this as a speaker amp for analog TV input vs optical ?

 

[Hotwetrat]

Looking for a headphone amp for my new AKG K371 and as any decent amp seems to cost around the same I might just go for this for an all in one solution (I currently have the Topping E30 DAC)

Does this thing still hold up 2 years later or has tech past it by?

Cheers.

EDIT confusion struck me - this is not a 'headphone' amp

 

[The Capstan]

Worse - the loxjie is a digital amp - no dac as such. Digital signals are processed to drive the PWM to the speakers directly with no analogue signal created (except directly on the output speaker posts).

The analogue input must first be digitised with an ADC before it can be amplified.

Sorry, but your statement is incorrect.
Among class-d amps there are FDA (full digital amplifiers) and amplifiers with analog input. The Infineon chip used in the A30 belongs to this latter category.Please have a look to the datasheet here:

https://www.infineon.com/dgdl/Infineon-MA12070-DS-v01_00-EN.pdf?fileId=5546d46264a8de7e0164b750002861a5

Please note Infineon has a FDA chip variant but this is not the type in use in the A30.

So the path for usb is: USB Interface chip (I think Realtek), ESS 9023 DAC, NJW1194 volume/tone control (analogue), MA12070 Class D amp.
In case of AUX in the signal is passed straight to the NJW1194. The benefit of this input is just the ability to use a better performing DAC/USB interface (like XMOS).

for sake of clarity.
Ale.

 

[antcollinet]

Sorry, but your statement is incorrect.
Among class-d amps there are FDA (full digital amplifiers) and amplifiers with analog input. The Infineon chip used in the A30 belongs to this latter category.Please have a look to the datasheet here:

https://www.infineon.com/dgdl/Infineon-MA12070-DS-v01_00-EN.pdf?fileId=5546d46264a8de7e0164b750002861a5

Please note Infineon has a FDA chip variant but this is not the type in use in the A30.

So the path for usb is: USB Interface chip (I think Realtek), ESS 9023 DAC, NJW1194 volume/tone control (analogue), MA12070 Class D amp.
In case of AUX in the signal is passed straight to the NJW1194. The benefit of this input is just the ability to use a better performing DAC/USB interface (like XMOS).

for sake of clarity.
Ale.

Ouch - thanks for the correction, I'll amend my post.

 

[Brightly]

Hi, just an update, I found that optical input works so will be using this for now and I will try to contact Loxjie to see if they know of a fix.

Did you work anything out with Loxjie? The same issue cropped up on my Win 10 machine after a year of use, for some reason.

 

[May Kasahara]

Sorry, but your statement is incorrect.

So the path for usb is: USB Interface chip (I think Realtek), ESS 9023 DAC, NJW1194 volume/tone control (analogue), MA12070 Class D amp.
In case of AUX in the signal is passed straight to the NJW1194. The benefit of this input is just the ability to use a better performing DAC/USB interface (like XMOS).

for sake of clarity.
Ale.

Sorry, but this correction also needs another correction.

In the USB signal path the Sabre ESS9023 DAC is NOT involved. The USB input is the only one that does not pass through the ESS9023.

Loxjie A30 Amplifier Review

Thanks a lot for your answers, I just bought another one!

www.audiosciencereview.com

"...The ES9023 DAC takes on digital-to-audio conversion for the Coax, Toslink and Bluetooth signals. But not the USB. Bummer. The internal DAC and "Headphone Amplifier" of the Realtek ALC4050 drive the NJW1194 volume controller directly. Even though the device supports I2S and could have been fed to the ES9023, it looks like we are left with whatever proprietary DAC exists inside the Realtek part, which probably isn't all that great. It's supposed to support 32-bit/384kHz but yet the DAC poops out at a 100 dBA SNR. Not a big deal, if you want better USB support, you can always get a USB-Toslink adapter and run that into the A30 to take advantage of the ESS DAC. But that's the only way if you're keen on USB audio."