Review and Measurements of Topping DX3Pro DAC and Headphone Amp

[richpjr]

What a load of total crap.

Because????

 

[y845133y]

I don't understand why you want ultra-low ESR in the signal path.

The capacitor equivalent circuit is as below. The cap has lower ESR, the signal loss in the cap will be lower. If the ESR=0, it will more like an ideal capacitor.

 

[simonchretien]

". So far I am using a plain USB cable. "

Well, try a 75$ USB cable, you might get 4D sparkling sound!

 

[ChuckT]

The capacitor equivalent circuit is as below. The cap has lower ESR, the signal loss in the cap will be lower. If the ESR=0, it will more like an ideal capacitor.
View attachment 21046

In real life audio, listening tells a different story. I have find audio grade caps (which is not design for low ESR) sounds better the low esr caps like the solid polymer. Film cap is better still, but unfortunately too big to fit.

 

[ChuckT]

Not certainly in that way. They are summarized in pairs. Look at the diagram and understand where to connect. The right part of the scheme Topping have done differently.

Tks, that's what I meant. I can take the output after the 2 coupling cap and connect to input of transformer. But I lose the advantage of "no caps in signal path". I think I can forgo one output and take L+/L- to the transformer and lose half the output drive.

 

[chrisliuboy]

OK, some exciting news to share with fellow DX3 owners!

When I looked at the 1KHz FFT test done by Amir, those little spikes around 1KHz were a big concern to me. Then people started to report edgy highs, shrills, all of those are pointing to LPF problem. Indeed, when I just got the DX3, I ran into the same problem with highs.

So to verify this, I tried different sampling rates – 44.1K, bad; 96K, still bad; 192K, highs improved; 352K, the edginess almost gone; then 705K, wow, the top is smooth and mellow now. Punchy sound, superb image!

Next is DSD. DSD64 (SACD is), no edginess yet the sound is a bit muddy and flat. DSD128, 256, 512, things are improving along the way. It’s at DSD512 this has totally changed! Wow! The sound stage is now wide opened! Beautiful top! Everything comes to alive! Each instrument is so three dimensional! You can even tell the size of the instrument. There’s a clear shape around it. Just so 3D! Stable, pin point image (looks like the clocks are not bad). When compared to ES9038 Pro running at DSD512, 9038 has a tad more etchiness on the top, more analytical. DX3 has more coherence, is more organic, and roundish. It can do better on vocals. The difference is subtle yet it’s there. Now I can see why AKM called this the velvet sound!

Yeah, still no mid-bass but I am not too worried about it now as this can be fixed. The sound still needs refinement here and there yet I am confident to say, after simple mods, this thing at DSD512 can easily beat most DACs under $2K!


A few extra points to mention:

. Obviously the cut off frequency of the LPF is set too high. Will have to open the machine to check the parameters to confirm this.

. Ranking of sound quality - DSD512 > PCM705 > DSD256 >> PCM352 > DSD128

. Even not all DSD512 sounds the same. The ranking – XiSRC > HQPlayer >> foobar2000

. I do have problem to play DSD512 from XiSRC under foobar2000. Still need to figure out what has gone wrong.

. When running foobar2000 for upsampling, make sure it’s set to high CPU priority mode otherwise you will hear clicks/hiccups.

. So far I am using a plain USB cable. The PC has 8 USB devices connected to it.

. If your computer can not handle DSD512, at least try PCM705K. Otherwise DSD256 is the one to recommend. Yes, DX3 is really meant for DSD.

. This thing is a beast!!! An unbelievable bargain at $200!!! 

Hmmm, I didn't see anything above 384khz... Did I install things wrong?

 

[y845133y]

I found some location can be added the capacitors for improving the sound. If you have more capacitor, you can try it.
1. DAC's Mclk oscillator power:

2. DAC's reference power, Analog Power (5v) and Analog Power (3.3v)

 

[ChuckT]

I found some location can be added the capacitors for improving the sound. If you have more capacitor, you can try it.
1. DAC's Mclk oscillator power:
View attachment 21054
2. DAC's reference power, Analog Power (5v) and Analog Power (3.3v)
View attachment 21055

wow, did you solder a 0603 (or 0402) ceramic cap directly on the ak4493 pins!!!
Replacing those yellow tan with ultra low polymer tan cap might work too.

https://industrial.panasonic.com/ww/products/capacitors/polymer-capacitors/poscap

 

[Cidious]

I found some location can be added the capacitors for improving the sound. If you have more capacitor, you can try it.
1. DAC's Mclk oscillator power:
View attachment 21054
2. DAC's reference power, Analog Power (5v) and Analog Power (3.3v)
View attachment 21055

You changed them but can you share how it will improve? What do you hear? what do you measure?

 

[lucadoc]

OK, some exciting news to share with fellow DX3 owners!

When I looked at the 1KHz FFT test done by Amir, those little spikes around 1KHz were a big concern to me. Then people started to report edgy highs, shrills, all of those are pointing to LPF problem. Indeed, when I just got the DX3, I ran into the same problem with highs.

So to verify this, I tried different sampling rates – 44.1K, bad; 96K, still bad; 192K, highs improved; 352K, the edginess almost gone; then 705K, wow, the top is smooth and mellow now. Punchy sound, superb image!

Next is DSD. DSD64 (SACD is), no edginess yet the sound is a bit muddy and flat. DSD128, 256, 512, things are improving along the way. It’s at DSD512 this has totally changed! Wow! The sound stage is now wide opened! Beautiful top! Everything comes to alive! Each instrument is so three dimensional! You can even tell the size of the instrument. There’s a clear shape around it. Just so 3D! Stable, pin point image (looks like the clocks are not bad). When compared to ES9038 Pro running at DSD512, 9038 has a tad more etchiness on the top, more analytical. DX3 has more coherence, is more organic, and roundish. It can do better on vocals. The difference is subtle yet it’s there. Now I can see why AKM called this the velvet sound!

Yeah, still no mid-bass but I am not too worried about it now as this can be fixed. The sound still needs refinement here and there yet I am confident to say, after simple mods, this thing at DSD512 can easily beat most DACs under $2K!


A few extra points to mention:

. Obviously the cut off frequency of the LPF is set too high. Will have to open the machine to check the parameters to confirm this.

. Ranking of sound quality - DSD512 > PCM705 > DSD256 >> PCM352 > DSD128

. Even not all DSD512 sounds the same. The ranking – XiSRC > HQPlayer >> foobar2000

. I do have problem to play DSD512 from XiSRC under foobar2000. Still need to figure out what has gone wrong.

. When running foobar2000 for upsampling, make sure it’s set to high CPU priority mode otherwise you will hear clicks/hiccups.

. So far I am using a plain USB cable. The PC has 8 USB devices connected to it.

. If your computer can not handle DSD512, at least try PCM705K. Otherwise DSD256 is the one to recommend. Yes, DX3 is really meant for DSD.

. This thing is a beast!!! An unbelievable bargain at $200!!! 

Could you explain how to set foobar to have upsampling?

 

[Pavano]

It seems this thread has derailed to audiophile territory

 

[splkn]

From the photo I assume DX3 is doing pretty much the same thing. Instead of using two OPs, the two summed up outputs are fed to one OP.

But this is not the same.

 

[splkn]

Tks, that's what I meant. I can take the output after the 2 coupling cap and connect to input of transformer. But I lose the advantage of "no caps in signal path". I think I can forgo one output and take L+/L- to the transformer and lose half the output drive.

Tell us about the benefits of limiting the signal path. And how the combination of signals will deprive you of this advantage.

 

[SIY]

I found some location can be added the capacitors for improving the sound. If you have more capacitor, you can try it.
1. DAC's Mclk oscillator power:

2. DAC's reference power, Analog Power (5v) and Analog Power (3.3v)

How did you determine that the sound "improved"? If the answer is, "Oh, I just listened," and there was no level matched double blind test or replicable measurements showing changes above plausible auditory thresholds, then what you've posted is worthless.

In real life audio, listening tells a different story. I have find audio grade caps (which is not design for low ESR) sounds better the low esr caps like the solid polymer. Film cap is better still, but unfortunately too big to fit.

Same question. Especially because I've posted measurements showing that for coupling duty, cheap electrolytic caps work as well or better than "audio grade."

Science, people, not anecdote and hand-waving.

 

[Cidious]

It seems this thread has derailed to audiophile territory

Why use a negative term like 'derailed' ? Just because you can't follow or are not interested it's derailing? Apparently many are interested and this forum is only for measurements and general discussion?

I really think comments like these are useless and waste of time. Why say anything when you can just be quiet and read over it if it doesn't interest you?

 

[mikehoopes]

I hope at some point we can send some modded units in for testing to put some meat on the bone here.

Today, I noticed that I lost USB audio output on my DX3 Pro. It indicated that it was switching to the desired sample rates, up to the max. PCM rate, but there was no audible output. BT audio was working fine.

I rebooted a few times, and then when I checked the Windows Mixer, noticed that Skype had been stealthily installed today (by Microsoft) and was one of the sources. I uninstalled Skype, and my USB audio became audible again. Did anyone else see this?

 

[y845133y]

You changed them but can you share how it will improve? What do you hear? what do you measure?

I add a lot of capacitors on the DX3-Pro. But only two solutions which I can hear some difference then before.
1. DAC's Mclk oscillator power: The sound has more detail.
2. DAC's reference power, Analog Power (5v) and Analog Power (3.3v) : The DAC's output is stronger and provides more low frequency.

 

[SIY]

I add a lot of capacitors on the DX3-Pro. But only two solutions which I can hear some difference then before.
1. DAC's Mclk oscillator power: The sound has more detail.
2. DAC's reference power, Analog Power (5v) and Analog Power (3.3v) : The DAC's output is stronger and provides more low frequency.

OK, so you didn't validate anything with any sort of measurement or controlled listening test.

Why use a negative term like 'derailed' ? Just because you can't follow or are not interested it's derailing? Apparently many are interested and this forum is only for measurements and general discussion?

There are 10^5 forums on the internet for audiophiles to swap stories and play make-believe. There is 1 where the focus is science and where claims are expected to be backed up, either by measurements or controlled listening. That is where you happen to be at the moment. Tall tales and make believe are pollution, not science.

 

[simonchretien]

I put some neon lights under my dx3 and the sound is now so detailed, its insane, try it.

 

[Stonetown]

OK, so you didn't validate anything with any sort of measurement or controlled listening test.



There are 10^5 forums on the internet for audiophiles to swap stories and play make-believe. There is 1 where the focus is science and where claims are expected to be backed up, either by measurements or controlled listening. That is where you happen to be at the moment. Tall tales and make believe are pollution, not science.

Yes. I want to see measurements to verify all these modifications please. Otherwise the mods are not serious and all these believes in modding tends to be like a fanatic religion.

Measurement data after modifications, please!

Cheers /Per