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Review and Measurements of Topping DX3Pro DAC and Headphone Amp

bleachershane

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2 different clicks - relay on and relay off inside unit. If it is impossible to fix it with firmware or drivers, it may be just replace this relay to noiseless one...
And is the unit clicking when you're just playing back a track but not doing anything such as going to browser Windows, etc?
 

Klenfo

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So when these clicks occur, say when you're using the seek bar, does the audio continue to play as you would expect? And is the unit clicking when you're just playing back a track but not doing anything such as going to browser Windows, etc?
Clicks do not affect to playback as far as I can see and with installed topping drivers there are no clicks with seek bar
During playback no clicks, after start and after stop only.
 

Bigsy

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Again, for me it only clicks after about 10 seconds of no output and will click again when something plays a sound. Play/pause seek etc all work fine if something continues to output, even just having something paused in another app or something will fix it. If the output is stopped it will take about 10 to 20 seconds for the problem to start. Topping driver makes no difference.

I would consider it fixed it it only clicked on actual rate changes, I understand software can't make a mechanical switch stop making a noise.
 
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wooptoo

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This might be a silly question but: does this unit accept analog input via the two coax inputs? (thus using it as an amp only?)
Thanks guys.
 
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i am just guessing the device dont want to play silence and instead of that relay disconnects some part of dac and turn it on when has input, have you tried turning off auto standby? (or i understand that function incorrectly)
 

Yuno

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i am just guessing the device dont want to play silence and instead of that relay disconnects some part of dac and turn it on when has input, have you tried turning off auto standby? (or i understand that function incorrectly)

Auto standby does nothing in regard to audio. It just turns off unit when input is no longer active (as in, you suspend or close PC)

I already explained what is happening and I'm 99% confident this is the case after lots of testing.
USB is needlessly resampling any input it receives. Normal (sane) behavior should be that resampling is done when sample of audio changes. You don't need to resample from 44.1 to 44.1 if DAC is already operating in 44.1, however you do need to resample 44.1 to 192 if input changes to 192. This is exactly what can be observed with toslink connection, switch from WASAPI mode foobar to youtube = click because 44.1 to 192. Switch from one 44.1 song to another 44.1 song in WASAPI foobar = no click because no resampling done.

USB and TOSLINK is not operating the same on this unit, which is pretty clear indication that something is very wrong.
By the way I wonder if improved perfomance of USB vs spdif observed in tests is somehow related to this.
 
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amirm

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Did you test your unit without using some form of exclusive mode?
I use ASIO interface on it using ASIO4ALL as I do all DACs. I just did some tests using S/PDIF and the linearity is better there. So there may be some issue related to ASIO4ALL wrapper.
 

bleachershane

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Auto standby does nothing in regard to audio. It just turns off unit when input is no longer active (as in, you suspend or close PC)

I already explained what is happening and I'm 99% confident this is the case after lots of testing.
USB is needlessly resampling any input it receives. Normal (sane) behavior should be that resampling is done when sample of audio changes. You don't need to resample from 44.1 to 44.1 if DAC is already operating in 44.1, however you do need to resample 44.1 to 192 if input changes to 192. This is exactly what can be observed with toslink connection, switch from WASAPI mode foobar to youtube = click because 44.1 to 192. Switch from one 44.1 song to another 44.1 song in WASAPI foobar = no click because no resampling done.

USB and TOSLINK is not operating the same on this unit, which is pretty clear indication that something is very wrong.
By the way I wonder if improved perfomance of USB vs spdif observed in tests is somehow related to this.
I don't think the word 'resampling' is the right to use here, which is why I was getting confused about the exact nature of the issues owners have talked about here.

Resampling in audio terms means conversion of one sample rate to another either by software or hardware methods: "Resampling or the more specific terms upsampling or downsampling usually mean sample rate conversion only. Low-quality resampling algorithms, whether upsampling or downsampling, can introduce artifacts which are clearly audible in the resampled audio file."

Now, I'm not certain exactly what's going on here with this issue, but it sounds like the DAC is unnecessarily re-initialising each time it receives data or there is a break in the data (seek, pause, etc). As someone else said, ideally the only time this change of sample rate 'click' should occur is when audio data is received that has a different sample rate to the last data sent to the DAC.

This could be caused by the hardware, the software, the way the hardware and software are interfacing with each other and if there is any other interruptions to the data stream from other drivers/software. It's all guesswork at this stage as 1) I haven't received my DX3 Pro yet and 2) I'm not a software engineer.

Anyone with this issue should be contacting Topping so that they work on a fix as soon as possible.
 
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amirm

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How much better?
I didn't save it but it had a more classical jagged edges at lower levels than USB. Seems like there is something of dithering/bit conversion going on which I can't yet explain.
 

NDRQ

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I didn't save it but it had a more classical jagged edges at lower levels than USB. Seems like there is something of dithering/bit conversion going on which I can't yet explain.

So better linearity from spdif, but lots of jitter and noise, so cant usable.
As i remember u said that the spdif and toslink input is bad.
 
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NDRQ

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And here is Toslink versus USB:

View attachment 16810

Seems to be worse than S/PDIF.

So USB is your best bet.

And here is Toslink versus USB:

View attachment 16810

Seems to be worse than S/PDIF.

So USB is your best bet.


Yes, i failed to remember correctly, you didnt said exactly that the other inputs are bad. But anyway itt looks worse.
You said that the linearity is effected by the the noise, but then why the noisiser spdif linearity is better?
An how is that 15 bit usb linearity effect the performance, when does it count?

I think about buying this thing, but now im a little bit confused.
 
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amirm

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Btw u said that the linearity is bad because the noise, but then why the noisiser spdif linearity is better?
My instrumentation can only use ASIO interface which is usually transparent but it may be not be in this case. As I said, I will keep investigating. For now, there is absolutely no fidelity issues for CD/streaming playback.
 

Haotify

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after 2 days of using, the unit die on me

1)Power indicator lighted up,
2)Able to access to menu by pressing the knob to change parameter,

However when i press the power on button, the power indicator will just blink and nothing appear.
 
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sghk

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Just wanted to chime in and add that my unit is also exhibiting the clicking behavior. Tried no Topping drivers and with drivers, resetting the unit, exclusive mode on/off to no avail. Switching between programs (Youtube, games, Spotify) seems to be the culprit in my case.
 

Bigsy

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I'm starting to wonder if there is anyone without problems?

If someone has a correctly working unit what is the device revision reported by the topping driver (in sys tray)?

Mine says v1.03
 
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