• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

Review and Measurements of Topping DX3Pro DAC and Headphone Amp

gypsygib

Member
Joined
Dec 29, 2018
Messages
63
Likes
27
Location
Canada
In DX3, the RCA outputs will go directly to the headphone amp. No relay in the middle to switch off the RCA outputs. In your case, the long RCA cable will behave like an antenna for the headphone amp hence the noise.

Thank you for a reply! You have no idea how much this has been confounding me. Why would the noise not be there if I have it set to dac mode? (Or maybe it's there and I just can't hear it above my JBL 305s amp noise?)

Also, what's the point of all the great measurements if it produces very audible noise with RCAs plugged in? Wouldn't that render the low distortion/noise measurements kinda pointless. I was going to RMA it but if they're all like that there's no point. May as well just return it.
 
Last edited:

finneybear

Active Member
Joined
Jan 22, 2019
Messages
220
Likes
110
Thank you for a reply! You have no idea how much this has been confounding me. Why would the noise not be there if I have it set to dac mode? (Or maybe it's there and I just can't hear it above my JBL 305s amp noise?)

Also, what's the point of all the great measurements if it produces very audible noise with RCAs plugged in? Wouldn't that render the low distortion/noise measurements kinda pointless. I was going to RMA it but if they're all like that there's no point. May as well just return it.

When you connect DX3 to an amp, the ground level will be established between the two machines, and the antenna effect will be reduced. You dont have to be worried too much.

DX3 is a $200 machine. To make money, Topping has to keep the part cost at $100. They do use good parts at key spots, in turn, have to cut corners on extras.
 

gypsygib

Member
Joined
Dec 29, 2018
Messages
63
Likes
27
Location
Canada
When you connect DX3 to an amp, the ground level will be established between the two machines, and the antenna effect will be reduced. You dont have to be worried too much.

DX3 is a $200 machine. To make money, Topping has to keep the part cost at $100. They do use good parts at key spots, in turn, have to cut corners on extras.

I have it connected to speakers and use the headphone out, the noise is pretty noticeable when on high gain.
 

finneybear

Active Member
Joined
Jan 22, 2019
Messages
220
Likes
110
I have it connected to speakers and use the headphone out, the noise is pretty noticeable when on high gain.

I see. There can be some loop in the chain. The noise will be picked up by the sensitive OP in the headphone amp.
 

gypsygib

Member
Joined
Dec 29, 2018
Messages
63
Likes
27
Location
Canada
I see. There can be some loop in the chain. The noise will be picked up by the sensitive OP in the headphone amp.

Like a ground loop? I've tested with just my laptop (not plugged in) and the DX3 on one outlet and I still get noise so long as the RCA cords are connected to it. Also, why would it only be on the right side?
 
Last edited:

splkn

Member
Joined
Jan 15, 2019
Messages
43
Likes
11
777 said:
I don't understand why you want ultra-low ESR in the signal path.
For coupling, you want low leakage current. Those KO caps are not bad either.
Next thing to look at is the noise and non-linearity.

For pass capacitors, a low ESR is not a priority. Much more important is its non-linearity at sound frequencies, which is higher in polymer tantalum capacitors. In this way, they contribute an equalizer effect.
 

Veri

Master Contributor
Joined
Feb 6, 2018
Messages
9,596
Likes
12,036
Can someone explain how to configure DX3 PRO in windows 10?
I can not bypass windows volume control.
And why this dac does not change sample rate on display according to sample rate of the music file (it is always 44.1)?
Thank you
Bypass volume controll, automatic change sample rate.. you just need wasapi/asio output, is no fault of the dx3pro
 

salvatorebg

New Member
Joined
Feb 26, 2019
Messages
3
Likes
0
Bypass volume controll, automatic change sample rate.. you just need wasapi/asio output, is no fault of the dx3pro
Thanks, but I dont undersrand your answer. I am already using wasapi and asio, but dac wont change sample rate on display.
 

Veri

Master Contributor
Joined
Feb 6, 2018
Messages
9,596
Likes
12,036
Thanks, but I dont undersrand your answer. I am already using wasapi and asio, but dac wont change sample rate on display.
That is weird, can you check ASIO control panel of your driver? It, at least, should be accurate. If it says 96Khz and your display 44Khz, display is bugged. If it says 44Khz, your ASIO or WASAPI set-up is not working properly.

test.png
 

salvatorebg

New Member
Joined
Feb 26, 2019
Messages
3
Likes
0
That is weird, can you check ASIO control panel of your driver? It, at least, should be accurate. If it says 96Khz and your display 44Khz, display is bugged. If it says 44Khz, your ASIO or WASAPI set-up is not working properly.

View attachment 22780
I have checked it. Control panel is always 44.1, same as DAC display. When I play higher resolution file it stays 44.1 It does not change.
Is it possible to change sample rate of the dac manually ?
 

Yuno

Active Member
Joined
Oct 26, 2018
Messages
215
Likes
266
I have checked it. Control panel is always 44.1, same as DAC display. When I play higher resolution file it stays 44.1 It does not change.
Is it possible to change sample rate of the dac manually ?

You don't have bitperfect playback setup, it will not work until you setup it properly. There is a lot of guides on the internet, look those up.
All you really have to do is 1. set dx3 sampling to something like 192khz (or whatever you wan't windows 10 allows up to 384khz as max sampling. All of those are overkill and way outside of human perfect hearing range), 2. check boxes to allow exclusive mode, 3. install wasapi plugin in foobar, 4. set output device in foobar to wasapi event or push.

I don't really recommend using any kind of bitperfect mode for most users. It's pain in ass if you use your PC for anything else than listening to music and you will hear no audible difference using it over direct stream set to 32bit/44.1 khz. Especially with dx3 since frankly bitperfect implementation on this device is subpar due to annoying relay clicking.
 

finneybear

Active Member
Joined
Jan 22, 2019
Messages
220
Likes
110
Like a ground loop? I've tested with just my laptop (not plugged in) and the DX3 on one outlet and I still get noise so long as the RCA cords are connected to it. Also, why would it only be on the right side?

When you use the headphone amp, just unplug the RCA cable. Ground loop. DX3 needs the ground level from the amp as the reference. Make sure the amp side is properly grounded.
 
  • Like
Reactions: 777

finneybear

Active Member
Joined
Jan 22, 2019
Messages
220
Likes
110
777 said:
I don't understand why you want ultra-low ESR in the signal path.


For pass capacitors, a low ESR is not a priority. Much more important is its non-linearity at sound frequencies, which is higher in polymer tantalum capacitors. In this way, they contribute an equalizer effect.

Here we are talking about the decoupling caps for power, not audio signal coupling. For signal coupling, EL caps have linearity problem, too. You also have to consider leakage current and microphonic and piezo effects, etc, a lot of other things.
 

gypsygib

Member
Joined
Dec 29, 2018
Messages
63
Likes
27
Location
Canada
When you use the headphone amp, just unplug the RCA cable. Ground loop. DX3 needs the ground level from the amp as the reference. Make sure the amp side is properly grounded.

Okay, thank you again for your assistance. I'll probably leave them plugged in for convenience but it's reassuring to know that my DX3 isn't malfunctioning.
 

finneybear

Active Member
Joined
Jan 22, 2019
Messages
220
Likes
110
Just bought an ESS 8620 based USB interface. It performs much better than XMOS and Amanero based solutions.
I am thinking of adding the following I2S interface to DX3:

i2s.JPG
 

Veri

Master Contributor
Joined
Feb 6, 2018
Messages
9,596
Likes
12,036
Just bought an ESS 8620 based USB interface. It performs much better than XMOS and Amanero based solutions.

Much better how? It really feels like this ESS interface is just the newest flavor of the month, after savitech/c-media/xmos/now ess usb chip originally made for sound bar application...

It's just DDC, can't imagine it makes a big difference on analog output.
 

ChuckT

Member
Joined
Jan 29, 2019
Messages
22
Likes
7
Mmmm... you meant the yellow caps around OPs? They are solid polymers from AVX. Both OPs have +-10 power supply. Cant find the Kemet KOCAP with 25V rating at the right size hence use the polymer from AVX. The LFP caps are film SMD parts.

The 100uf/25V SMD caps are CDE HZA type, it's a new generation hybrid cap.

I doubt that those AVX tan cap are solid polymer as sold polymer tan are much more expensive than the normal tan and unlikely to be use in such a low cost dac. Another hint is the yellow tan mark is 107A meaning 100uf 10v. If polymer tan, only 6.3V is required instead of twice the voltage rating required for normal tantalum. If those AVX are really solid polymer, there is no need to replace them with KoCap which is also a polymer cap.

I might replace those yellow AVX tan with polymer tan with a higher value solid polymer tan (220uf 6.3V B case size and 100uf 6.3V 1210 size).
I am looking at mouser parts "T520C227M006ATE015" and "581-TCJB107M006R0040"
 

Yuno

Active Member
Joined
Oct 26, 2018
Messages
215
Likes
266

THEV

Member
Joined
Feb 21, 2019
Messages
30
Likes
9
It sounds the same as other DACs I tried, but either way don't buy dx3 pro until topping officially communicates that they fixed currently existing issues.

I am looking to get an JDS atom but I dont want to bother with unplugging my headphones for my powered monitors to work, so Ill need an dac that has multiple outputs. DX7s might be the solution but it seems somewhat overkill to both have the atom and the DX7s
 
Top Bottom