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Review and Measurements of Topping NX4 DSD Dac and Portable Headphone Amplifier

Joined
Feb 12, 2019
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Create an impulse train, 100Hz @ -3dB and save it to a FLAC file:

Python:
import numpy as np
import soundfile as sf

data = np.zeros(44100)
data[::441] = np.sqrt(2)/2

track = np.tile(data, 500)
stereo = np.column_stack((track, track))
sf.write('100hz_3dB_impulse.flac', stereo, 44100, subtype='PCM_16')
Play the generated file through the NX4 in DAC-only mode and look at one of the output channels on an oscilloscope.
Looks linear-phase to me...

View attachment 22193
Very cool. Thanks for the work! I suspected LP because my Sony MDR-1A headphones sound bloated with mimimum phase filters on my ESS-based Oppo 205’s headphone amp (but sound great on LP filters); and, they do NOT sound bloated on the NX4 DSD. In fact, I’m loving the sound on all my Sony headphones with the NX4 DSD.

Thanks again for the impulse capture on your oscilloscope.
 
Joined
Feb 17, 2019
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Anybody having problem with their NX4DSD regarding the issue with PCM 768k? I discovered on both of my unit (early silver, probably rev 1 with pentalobe screw and rev 2 black with flat head screw, wrongly dismissed as my fault on 1st unit due to i dropped it before, when i got 2nd one then its not my fault :p ) that when you use the upscaling feature on your music player (I used Neutron Pro on my Android and HQPlayer on PC, pm me for exact settings), crank it up to the max PCM 768k (advertised by Topping as supported) after some playback time the NX4DSD would fail to produce sound and only output static/white noise. A reboot (turn off and on) would restore it back to normal. Also the sound is very noisy when input with 768k, dialed it back to 384k and lower then clean sound again. I think there is a bug on the XMOS chip, IDK.
I tested again today and the problems still persist. Can anybody knows Topping atleast report this to them? I dont have the contact.
 
Joined
Jan 25, 2019
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Create an impulse train, 100Hz @ -3dB and save it to a FLAC file:

Python:
import numpy as np
import soundfile as sf

data = np.zeros(44100)
data[::441] = np.sqrt(2)/2

track = np.tile(data, 500)
stereo = np.column_stack((track, track))
sf.write('100hz_3dB_impulse.flac', stereo, 44100, subtype='PCM_16')
Play the generated file through the NX4 in DAC-only mode and look at one of the output channels on an oscilloscope.
Looks linear-phase to me...

View attachment 22193
Nice! Thanks.. Sorry my incompetence, but what is more specifically: fast-roll off or slow-roll off?
 
Last edited:
Joined
Nov 27, 2018
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Is it true that if I use the unit while its charging it would degrade the battery? Thinking its a pretty solid desktop driver for me. I already got the unit with me and its amazeballs but I'm just scared to test out my theory
 

bravomail

Active Member
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Oct 19, 2018
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I had the issues with SMSL Idea (Sabaj Da2) playing upscaled files. Sound became "thread-like", or "lifeless". I promptly ditched the idea. Modern DACs do upscaling internally, so running your own upscaling is detrimental. I suggest you use "native" track sampling frequency with as less processing as possible in the way.
Also - try to do AB comparisons with upscaled and untouched recordings. I suspect that reported 768k PCM is for ads, not really tested or used.
Anybody having problem with their NX4DSD regarding the issue with PCM 768k.
 

bravomail

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I'm still surprised this gets Amir recommendation despite high freq roll-off. FX Audio X6 has similar roll-off and destroyed by every reviewer because of that.
 

Rollingsound514

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Does Windows 10 need a driver install for this to work properly? I won't throw anything at it more than 192 24 through Tidal app or Foobar.

Also, this won't be ON all the time but it will pretty much almost always have external power to it when it IS on, I'm commuting by car now and don't need this unit for the commute anymore and this unit is just gonna live on my desk at work...
 
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amirm

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Does Windows 10 need a driver install for this to work properly? I won't throw anything at it more than 192 24 through Tidal app or Foobar.
As I noted in the review, no:

For subjective listening I used the USB class driver in Windows 10 creators edition using Roon player for bit-exact playback.
 

HGNBB

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Nov 15, 2018
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Would this be a better setup than a chord mojo if using with HD800S, AEON Flow, LCD-x, Empire ears phantom/Campfire Audio Andromeda ?
 
Joined
Nov 19, 2018
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Hi guys, I recently purchased the NX4 DSD for desktop usage, I used it for a few hours connected to my PC via micro usb on the DAC port of the NX4 DSD but now it no longer turns on. It will only charge from the USB charge port. I'm assuming I will need to now have two micro usb cables connected simultaneously to use this properly as a stationary desktop headphone amp?

EDIT: Ok, so it definitely needs two usb cables to be connected simultaneously to keep it "charged" to be used as a desktop headphone amp. It's an awesome little amp/dac. Even the bass boost is very good, it doesn't sound distorted like some.

A little tip if anyone wants to use this on their desktop, just gets some 10lbs or 5lbs heavy duty velcro strips and mount it directly under your desk, this allows you to easily turn the volume nob without having to lift up the dac to adjust the volume, it holds it extremely well.
 
Last edited:
Joined
Nov 27, 2018
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Hi guys, I recently purchased the NX4 DSD for desktop usage, I used it for a few hours connected to my PC via micro usb on the DAC port of the NX4 DSD but now it no longer turns on. It will only charge from the USB charge port. I'm assuming I will need to now have two micro usb cables connected simultaneously to use this properly as a stationary desktop headphone amp?

EDIT: Ok, so it definitely needs two usb cables to be connected simultaneously to keep it "charged" to be used as a desktop headphone amp. It's an awesome little amp/dac. Even the bass boost is very good, it doesn't sound distorted like some.

A little tip if anyone wants to use this on their desktop, just gets some 10lbs or 5lbs heavy duty velcro strips and mount it directly under your desk, this allows you to easily turn the volume nob without having to lift up the dac to adjust the volume, it holds it extremely well.
good to know. Could you say if you have notice some battery failures or degradation , because on massdrop JUST ONE person said that using it like this would degrade the battery life.So I took it with a grain of salt.
 
Joined
Feb 28, 2019
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What kind of cable do I need to get audio from my laptop to Topping NX4? I guess the mini USB-to USB used for charging won't cut, do I need one with a headphone jack?
 
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What kind of cable do I need to get audio from my laptop to Topping NX4? I guess the mini USB-to USB used for charging won't cut, do I need one with a headphone jack?
You will need a mico USB to go from the dac port to your PC. So Micro-USB A to Male USB A
 
Joined
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good to know. Could you say if you have notice some battery failures or degradation , because on massdrop JUST ONE person said that using it like this would degrade the battery life.So I took it with a grain of salt.
Good question, I don't have the tools to measure the battery life though.
 
Joined
Feb 28, 2019
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You need a USB to Micro USB cable.
I tried that but the audio still comes out of the laptop speakers, there is no option to switch to headphones. I think its still not fully charged, maybe that is why? The power button turns off when I take the mini usb cable from the charging port.
 

MrC

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I tried that but the audio still comes out of the laptop speakers, there is no option to switch to headphones. I think its still not fully charged, maybe that is why? The power button turns off when I take the mini usb cable from the charging port.
We are talking about the NX4 DSD?

If so, there are two micro usb ports on the back, one is for charging and the other for connection to PC (or phone, tablet etc.) labelled "DAC".

Once your PC is connected to the NX4 via the usb cable, turn on the unit and it should auto install, if you are running Windows 10. If you are running Windows 7 then you will probably need to download the drivers from the Topping website.

Once it is installed, you can choose the NX4 DSD as the primary output.
 
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