Review and Measurements of Topping DX3Pro DAC and Headphone Amp

[noel_fs]

As you can work in Chinese, there is something you could do that would be rather useful if you can explain it to Topping. On the remote for my Topping DX7s there is (IMHO) an obvious error of logic that should be changed but I fear that it will need someone fluent in Chinese to explain. Here we go....

Buttons such as FIR (filter selection) and AUTO (auto power ON/OFF) serve as both interrogation [tell me what mode am I currently using?] and change (by pressing the button again). Problem is, the first press changes the state and it is necessary to press the button – five further times in the case of FIR – to get back to where you want to be. Logically, the first press should be just interrogation. After a couple of seconds, the display should return to its default state and NOTHING should have changed. It is only a second press – before the display returns to its default state – that should cause the function to change.

Another logical fault is the ease with which DAC mode can be selected. This is the mode in which the volume control is bypassed and the unattenuated DAC output level is sent to the power amp. This has the potential to be harmful (and possibly, dangerous to hearing). The selection of that mode really needs a safeguard involving a second press of a different button ( to safeguard against accidentally double-pressing a single button).

If you could explain the above to Topping, you would be doing their business, and us, a great favor

I would say that only with the first press should be an interrogation and the second change the function, at least on some of the features like Filters, probably topping can do it

@TP-wang

 

[Pluto]

I would say that only with the first press should be an interrogation and the second change the function

Is this not what I suggested, or do you read it as something different?

Provided the second press occurs before the display reverts to default, it should be treated as change.

In other words, a press taking place when the screen is at its default means interrogate.
A press taking place while the interrogation result is being displayed means change.

 

[slazyel]

Hi guys,

I'm newbie at this, so sorry if it's a stupid question but how can i use it as both amp + dac for a 3.5mm headphone?
In the Manual it looks it just work as either a Dac or a Amp, but not both together. Is there a way to make it happen? I bought it just because it was a dac + amp combo, if i have to choose one of them, either dac or amp, i think i will have to send it back :/

 

[Cidious]

Cidious, how did you manage to remove PCB ? Did you give your front panel down ?

Like you said before. Get a long hex key 2mm and 20cm I got myself. And remove the two screws on the side inside of the front panel. Then you can flip it down and remove the four screws to detach the display. Which then you can pull out with the board from the back or front all as you please. Just get that tall 2mm inbus/hex key.

 

[yue]

I would say that only with the first press should be an interrogation and the second change the function, at least on some of the features like Filters, probably topping can do it

@TP-wang

His name is tp-Wong, not wang.

 

[Stonetown]

Hi guys,

I'm newbie at this, so sorry if it's a stupid question but how can i use it as both amp + dac for a 3.5mm headphone?
In the Manual it looks it just work as either a Dac or a Amp, but not both together. Is there a way to make it happen? I bought it just because it was a dac + amp combo, if i have to choose one of them, either dac or amp, i think i will have to send it back :/

Press center button on the remote and the head phone symbol flashes. However volume control is active on both the phones and the line out connectors. If we want the DAC stay at fixed level at the line out connectors, while adjusting the head phones level, I don't know.. That would be good also, but not so important for me.

 

[slazyel]

Press center button on the remote and the head phone symbol flashes. However volume control is active on both the phones and the line out connectors. If we want the DAC stay at fixed level at the line out connectors, while adjusting the head phones level, I don't know.. That would be good also, but not so important for me.

So, when the headphone symbol is flashing it means it's using both Dac and Amp for the headphones?

 

[bleachershane]

So, when the headphone symbol is flashing it means it's using both Dac and Amp for the headphones?

It means the headphones are volume controlled and the line output is also volume controlled as opposed to fixed line level out.

What is it you mean when you say "how can i use it as both amp + dac for a 3.5mm headphone?"

 

[slazyel]

It means the headphones are volume controlled and the line output is also volume controlled as opposed to fixed line level out.

What is it you mean when you say "how can i use it as both amp + dac for a 3.5mm headphone?"

Oh ok. About what i mean: I want to know if it can work as both a digital to analog converter and still being able to amp my headphones. And if so, how can i make it work like that? For example, when i set to DAC with the remote, there's no sound, only when i set it to usb. Does that mean when it's setted to USB and headphone symbol showing on the screen that only the amp is working?

Forgive me if i said something stupid but i'm really a newbie at the audiophile world =p

 

[finneybear]

I plan to:
1. Use a transformer output instead of an op amp.
2. Replacing the TPS54331 with the TPS54332 (1 MHz instead of 570 kHz) Or simply abandon Step-Down in the DAC's power supply.
3. Simple recloker on flip-flop and NDK between AK4118 and AK4493

P.S. to bleachershane. For me, the DX3Pro is interesting as a donor and acquaintance with the new AK4493 chip. In addition, Topping engineers have done a good job in a tight price range for the product.

Hello Pavel, nice to see you here.

Just wondering whether you have compared AK4493's sound against your DSC2 at DSD512?

 

[Stonetown]

Oh ok. About what i mean: I want to know if it can work as both a digital to analog converter and still being able to amp my headphones. And if so, how can i make it work like that? For example, when i set to DAC with the remote, there's no sound, only when i set it to usb. Does that mean when it's setted to USB and headphone symbol showing on the screen that only the amp is working?

Forgive me if i said something stupid but i'm really a newbie at the audiophile world =p

Digital to analog converter is connected either to the phones output, or to the line output, or to them both but in this case with the volume control active. When the volume control is active in the line output, it is called "Pre amp mode". The "DAC-mode" is here referring to that the line output is connected to the digital to analog converter without the volume control circuitry engaged, and could theoretically give better audio quality, but measurements have shown that the audio quality is not negatively affected when the volume control is engaged (see the test results shown for head phone output).

So if you accept having "Pre-amplifier mode" instead of the "DAC-mode" simultaneously with the head phones, Fine! You get the functionality of the digital to analog converter connected to both outputs simultaneously. Only difference is that the DX3 Pro volume control is adjusting the line output at the same time as the head phones. This is standard for analog pre amplifiers, but if you need a FIXED audio level output from the line connectors, at the same time as you are using the head phones (like tape output in old preamps), this is not possible. You have to live with that the both outputs are varied with the volume control at the same time. Trying it yourself is maybe the easiest way, if you have the DX3 Pro already. Cheers!

 

[gypsygib]

Could you check whether the one without the problem has the option "auto standby mode" off?
I believe the sleep is caused by a bug in their "auto standby mode".
It's in the settings (refer to last page of the manual) --- AO turns that mode on (factory default) and AC turns that mode off.

Didn't the D10 have a standby issue as well that was fixed (or maybe introduced) via a firmware.

 

[zephyros]

Does anyone use the DX3Pro on linux? Whenever I stop/start playing something on Linux, there's a faint buzz sounds, and the USB sign flash (which means no signal I think?). How to deal with that?

 

[Sucram]

Hi everyone, I am now feeding my o2 amp with a Schiit Fulla 2 as the dac. I am going to get an upgrade to my set up or at least upgrade the dac. I'd like to ask how does the Massdrop o2 + SDAC measure compare to the DX3? The DX3 is more powerful than the o2? Which pair would provide a cleaner sound, and can drive the HD650 better? Are there any other DAC/amp combo that you might recommend, in this price range?
Thanks, I look forward to your kind response.

 

[yue]

Hi everyone, I am now feeding my o2 amp with a Schiit Fulla 2 as the dac. I am going to get an upgrade to my set up or at least upgrade the dac. I'd like to ask how does the Massdrop o2 + SDAC measure compare to the DX3? The DX3 is more powerful than the o2? Which pair would provide a cleaner sound, and can drive the HD650 better? Are there any other DAC/amp combo that you might recommend, in this price range?
Thanks, I look forward to your kind response.

dx3 will for sure outperform o2+sdac. the dac measurements of the two dacs proof that. the amp part, dx3 is also better as it has a digital volume control. it has less power than O2, but believe me you won't go that far.
also dx3 provides far more features, such as coax/spdif/bluetooth input, remote control, etc.

However, if you're ok with separate devices, at the same price you can get a jds atom with a khadas tone board, and they will kill everything else measured in this forum.

 

[Pavel]

Just wondering whether you have compared AK4493's sound against your DSC2 at DSD512?

My DX3 is not delivered yet.
I myself am very interested in comparing DX3 sound in direct dsd + HQPlayer.
I am sure that the sound quality will be high. Because the main contribution to the sound will be from HQPayer.

 

[Toku]

Could you check whether the one without the problem has the option "auto standby mode" off?
I believe the sleep is caused by a bug in their "auto standby mode".
It's in the settings (refer to last page of the manual) --- AO turns that mode on (factory default) and AC turns that mode off.

I switched the mode from A-O to A-C and I'm doing 72 hour continuous playback test.
Sleep has not occurred so far. I will continue the test for another 48 hours after this.

 

[Toku]

thanks. So you don’t have issue running in AO mode in the past 72 hours? I remember a forum member run into the issue after one week of continuous playing.

The issue presents in usb and spdif so far so I believe it is not related to the usb interface or pc hardware. I am inclined to believe it’s related to a bug in the power control code — it resides either in XU-208 (this chip does many things else in addition to USB interface) or an STM8 microprocessor (handles a lot of things, such as the digital display). The code might falsely assume the data steam finished, and enter standby mode automatically.

Another question I have is, does pressing the knob turn the machine back on immediately? If yes, does the input selection stays the same as last time?

If Topping could publish the code we can debug it together. But Probably they don’t even have the code themselves . Damn

I understand everything you say.
I will verify as long as possible.
I am testing with two DX3 Pros.

In addition to the sleep problem, Topping DX 3 Pro has a problem of suddenly playing back large noise during PCM 768 k playback.
As you examine it, this problem seems to be related to indoor temperature. It hardly occurs in the cold winter season.
Once a symptom occurs, it will not resurrect until you play a song other than PCM 768k. Of course, this case is reported to Topping.

 

[Pavel]

Does anyone have an explanation for the paradox that headphone output is significantly better for SNR and THD?
Indeed, in the block diagram Topping headphone amplifier is after RCA. Therefore, THD and SNR can only be the same or worse.

amirm , can your jack3.5 cable be better than RCA?

 

[slazyel]

Hi guys, another newbie question:

Which bit rate do you guys recommend for the DX3 Pro? I'm using it with a Beyerdynamic T1 and use it mainly for listening to 320kbps music (Streaming service) and playing games, lots of.

Currently i'm using 24/96 but the standard setting appears to be 32/44.1. Any recomendation about which bit rate to use?