Review and Measurements of Topping DX3Pro DAC and Headphone Amp

[Rollingsound514]

Checking in, have 2 units (one serving as a DAC/Pre amp in my living room stereo setup and the second as my desktop DAC/Headphone solution. No problems so far. If there's no signal going to it for a lonnnng time some times it'll go into standby mode even if I cancelled it but whatever I don't care. Nothing else to report 2 months in

 

[Yuno]

If there's no signal going to it for a lonnnng time some times it'll go into standby mode even if I cancelled it but whatever I don't care.

Units going into suspend mode on their own clearly indicate there is some issue. Whether you care or not is not relevant.
Frankly, it doesn't bother me too much at the moment too, but it will bother me if one of those shutdowns will be for good.

 

[RayDunzl]

Can you guys with shutdown put a piece of tape in front of IR sensor and see if it still shuts down? Some monitors emit IR that can cause the receiver to do things.

I don't see any replies to this.

Just for the record, I too had a device that, when the PC monitors (with fluorescent tube backlight) were on across the room and facing it, would not respond to the remote.

 

[Stein]

My DX3 Pro is currently being sent to Topping for analysis. I'm curious what they'll discover

 

[amirm]

I am also getting a unit that has gone into standby and won't come out.

Meanwhile Yue's unit continues to work solid as a rock in daily use (and system shutdowns in between).

 

[david99]

My DX3 Pro is currently being sent to Topping for analysis. I'm curious what they'll discover

Did you have permanent standby issue?

 

[Stein]

Did you have permanent standby issue?

Yes, I did. It turned itself off 3 times before it got stuck in standby mode... FOREVER!

 

[noel_fs]

I am also getting a unit that has gone into standby and won't come out.

Meanwhile Yue's unit continues to work solid as a rock in daily use (and system shutdowns in between).

System shutdowns do you mean dx3?

 

[artburda]

I am also getting a unit that has gone into standby and won't come out.

Meanwhile Yue's unit continues to work solid as a rock in daily use (and system shutdowns in between).

Have you also tried running dsf-files and really pushing the headphone out (-1 DB)? I tried this yesterday with a cheap no name self-powered 2.1 speakers combo, that can only be connected by a 3.5mm jack that runs into the sub-woofer which has an integrated amp. I was playing it from musicbee with ASIO (DoP). FLAC files were playing fine, but as soon as I tried a dsf-file I got terrible static noises and could barely here the music in the background. I had to delete all DX3 drivers and unplugged and resetted the DX3 multiple times, reinstalled musicbee to be able to play music again, because almost all FLAC files had also static noise when played. I guess I'm really lucky that it works again

 

[Hyldig]

Have an order on Aliexpress and was just contacted by seller, that because of the issues with the DX3 discussed on forum ( i guess here ), they have to test all products in warehouse before processing orders, and this will delay delivery.

I'm starting consider cancelling and go with a A30 + D30 combo instead...
The main feature DX3 have over this would be the bluetooth input, right?

 

[Veri]

Have an order on Aliexpress and was just contacted by seller, that because of the issues with the DX3 discussed on forum ( i guess here ), they have to test all products in warehouse before processing orders, and this will delay delivery.

That sounds pretty good for the end-user/consumer actually pity about the delay but sounds like good initiative.

On the other hand. What kind of test do they do to perform to determine if the device will shut down weeks/months later?
Do they know something we don't?

 

[Hyldig]

That sounds pretty good for the end-user/consumer actually pity about the delay but sounds like good initiative.

On the other hand. What kind of test do they do to perform to determine if the device will shut down weeks/months later?
Do they know something we don't?

Not much details, but here is what i got, in the best chinese english

First message:
A happy day, first of all, I am very sorry to bring you trouble, because at present TPPING DX3 PRO we received some buyers to suggest us some problems with the product, we are currently testing all the products in our warehouse, because of the Chinese New Year holiday Just after the end, we received a batch of new products from the factory.
In order to ensure the quality of the products, and solve the customer's problems before the product has been reflected, you can use the forum to understand some of the problems that may arise in order to better serve our buyers and friends, we decided to extend the products you purchased.
Some shipments, of course, we will send you products within the time limit set by AliExpress, please rest assured. We will use these time to conduct a 48-hour broadcast test on the product's possible amp and crash, and use the 110v and 220v voltage tests separately. We will arrange for the test without problems, but we will not be able to ensure that during this test. There is no problem with the product after the test, and our test is only to reduce some of the possible situations.

Second message:
We are very sorry to bring you trouble. For the series of problems that TOPPING DX3 PRO has appeared in the forum, TOPPING officially began to re-complete and improve the product again.
In order to ensure the quality of the products and better serve the customers, TOPPING official requirements, all current DX3 PRO orders will be tested at 110v and 220v for a long time before leaving the factory. It will take some time during this period.

 

[simonchretien]

Not much details, but here is what i got, in the best chinese english

First message:
A happy day, first of all, I am very sorry to bring you trouble, because at present TPPING DX3 PRO we received some buyers to suggest us some problems with the product, we are currently testing all the products in our warehouse, because of the Chinese New Year holiday Just after the end, we received a batch of new products from the factory.
In order to ensure the quality of the products, and solve the customer's problems before the product has been reflected, you can use the forum to understand some of the problems that may arise in order to better serve our buyers and friends, we decided to extend the products you purchased.
Some shipments, of course, we will send you products within the time limit set by AliExpress, please rest assured. We will use these time to conduct a 48-hour broadcast test on the product's possible amp and crash, and use the 110v and 220v voltage tests separately. We will arrange for the test without problems, but we will not be able to ensure that during this test. There is no problem with the product after the test, and our test is only to reduce some of the possible situations.

Second message:
We are very sorry to bring you trouble. For the series of problems that TOPPING DX3 PRO has appeared in the forum, TOPPING officially began to re-complete and improve the product again.
In order to ensure the quality of the products and better serve the customers, TOPPING official requirements, all current DX3 PRO orders will be tested at 110v and 220v for a long time before leaving the factory. It will take some time during this period.

What does this mean exactly for existing users?
By "extend the product", do you mean that Topping is extending the warranty period?

 

[Veri]

What does this mean exactly for existing users?
By "extend the product", do you mean that Topping is extending the warranty period?

Either a bad translation, or a DX3S is incoming.

 

[amirm]

System shutdowns do you mean dx3?

No, no. I mean I power my whole computer down when I am not using it. The DX3 always powers up fine on the next start-up.

 

[Poultrygeist]

I'm using the DX3 into a passive preamp controlling a flea watt SET amp. Was hoping this DAC/pre/amp would provide some additional gain. From it's line out mode I'm getting no more than the D30?

 

[finneybear]

Very busy with work these days dealing with a few big projects. Finally got time over the long weekend to pull up the main board and strip out caps and key resistors. Now I got this very nice bare board.

Time for the real fun!!!

 

[david99]

Very busy with work these days dealing with a few big projects. Finally got time over the long weekend to pull up the main board and strip out caps and key resistors. Now I got this very nice bare board.

View attachment 22202


Time for the real fun!!!

Which kind of components are you going to use instead of striped ones?

 

[finneybear]

Some finding so far:

The XOs are NDK 2520SA series. Decent enough for this player . May switch to 2520SDA later if the machine does well after the mod.

Tested 5 or 6 stocks caps. At 120Hz, their value is only about 80uf. At 1KHz, the value drops to 70uf something. The Q value is only 3. Very bad caps. Definitely no good for the DC bulk converters.

The 8 caps around OPA2140 and headphone output buffer are all coupling caps. They need to be replaced with audio grade caps.

AK4493 needs big bypass caps for analog power supply. 100uf used here is too small.

The LPF is a simple first order design with fc at 160KHz. For DSD, this is not an issue because 4493 will have an internal LPF kick in at DSD mode.
160KHz may be a bit high for 44KHz PCM. I am thinking of reducing it to 120-130KHz and adding a small cap to ground for very HF switching noise after the 1.43K ohms input resister. The main problem is there's not much space for me to redo the LPF.

Will replace all key resisters with tantalum nitride chips. cost $$$

Tantalum polymer caps are still not good enough for audio signal coupling. Niobium oxide parts can be considered. Looks like 100uf Elna Silmic may fit. I will use only one set of outputs for each 4493 for now so not too worried about the coupling cap.

Tried OPA1612 on another AKM 449X DAC. Indeed, the top is a bit aggressive. mid-bass is lacking. Not a surprise here as I had talked about OPA1612's phase shift problem below 1KHz on diyaudio. Will try MUSES 8920 yet that one may be a bit weak on bottom, too.

 

[777]

There is a 1nF cap after 1.43k resistors on a positive signal rail. Four capacitors in the headphones amplifier are for decoupling of the diodes in the output stage. There are 1ohm resistors in series with 10v power supply rails, between voltage regulators and headphones amplifier.Maybe it is better to put in parallel an inductor with 0.1ohm DCR and 10uH.