Review and Measurements of Topping DX3Pro DAC and Headphone Amp

[bleachershane]

SOIC should not be a problem perhaps it could be done more elegantly, but my approach is as follows:
A. Desoldering.
1. Put some flux on pins.
2. Heat all 4 one side pins with T12-K tip (or any other appropriate). Temperature controlled soldering station is a must.
3. With forceps catch the package and very slightly elevate heated side to detach the pins. Opposite pins will bent a little.
4. Heat opposite pins and remove the package.
5. Wick excess of the solder from pads.
B. Soldering.
1. Carefully adjust the package on the pads and fasten it touching 1/5 pin with soldering tip.
2. Take a second look is it OK.
3. Properly solder pins 1-8.

It might be even easier with hot air reworking gun, but I do not like to use it in crowded areas

That's a great little guide, gives me confidence it can be done, I just need to look out my various tips to see what I've got. Sadly no hot air reworking gun, but do have a temperature controlled station.

 

[Sangram]

The easiest way to remove SOIC from PCBs is to use a thick ~19AWG wire and bend it into a loop, like a U. Place the straight lines of the U on both sides of the chip making sure of full contact on the top of the pins. Heat the rounded part of the U with a hot ~260-280 iron, the heat will travel along the wire and the chip can be knocked off once the solder is melted through. Works great for caps, resistors as well, you only need the tip of the U on each side.

Trying to lift the chip is asking for trouble. You can use a small bread knife to saw one side of pins off the chip, then you can try lifting the other side.

 

[TP-Wong]

FYI I happened to be able to make the second DX3 Pro go into standby when inserting the headphone jack into it. I turns back on and remains functional. I can't replicate the conditions though. Those of who have had standby issues, is it related to plugging in the headphone?

It shut down because of the headphone jack short circuit the headphone amp, this make too high current and caused power protection.

 

[TP-Wong]

Hi every one, we find reasons and solutions, I updated it here:
https://www.audiosciencereview.com/...c-and-headphone-amp.4967/page-142#post-150957

 

[TP-Wong]

I have suspicions....
The problem is possible in not the OPA2140 itself, but in the technological process. Topping uses refractory solder. When assembling PCB at the factory, they were forced to raise the temperature above 275C. Apparently for such harsh conditions, the OPA2140 turned out to be a weak link. Very similar to the overheating of the chip when soldering. It may still live for a while, but then it will die.

The chip is also an electronic product, so there is also the possibility of manufacturing defects. We have really met this problem before.

 

[Veri]

Hi every one, we find reasons and solutions, I updated it here:
https://www.audiosciencereview.com/...c-and-headphone-amp.4967/page-142#post-150957

Great information

 

[Yuno]

Hi every one, we find reasons and solutions, I updated it here:
https://www.audiosciencereview.com/...c-and-headphone-amp.4967/page-142#post-150957

What about units that are not dead, but go into suspend once in a while? This is the case for mine, it turned itself off on it's own like 6-7 times since I bought it, op amp itself is not dead for sure because I am able to turn it on every time this happens.
I already put mine into box and went back to using my older dac, I'm just not sure what to do. If I send it back to seller, the unit doesn't even appear broken (it will turn on and work, it would require like 2 weeks of testing to experience this self-shutdown issue, at least that's about how often this happens to me).

 

[thunderchicken]

Dear users

Suggestions to users who already met this problem.
If your unit met "standby problem". No matter where you bought it, we will service directly to you. Please contact ([email protected]) for sending the defect unit back to us, we will pay back your shipping fee so you will not lost money in this issue, after receiving it, we send you a full new unit for exchange.

I am sorry that our explanation came too late and made some users worried.

This is exactly the kind of thing that makes customers come back to your brand- I wish every company was this good! I will happily buy more Topping products

 

[Deleted member 3566]

I'm confused. Have you fixed the issues in the batches, or are you proposing to do so? I'm still waiting for a proper confirmation here, as I'm interested in a purchase.

 

[amirm]

Suggestions to users who already met this problem.
If your unit met "standby problem". No matter where you bought it, we will service directly to you. Please contact ([email protected]) for sending the defect unit back to us, we will pay back your shipping fee so you will not lost money in this issue, after receiving it, we send you a full new unit for exchange.

This is great. It resolves the main issue owners had with getting units fixed.

 

[Wolven]

What about units that are not dead, but go into suspend once in a while? This is the case for mine, it turned itself off on it's own like 6-7 times since I bought it, op amp itself is not dead for sure because I am able to turn it on every time this happens.
I already put mine into box and went back to using my older dac, I'm just not sure what to do. If I send it back to seller, the unit doesn't even appear broken (it will turn on and work, it would require like 2 weeks of testing to experience this self-shutdown issue, at least that's about how often this happens to me).

Yes, I too want to know. My unit has been off easily 7-8 times since I bought it. I have used headphones for less than 30 hours, and I'm not willing to test and push my luck.

 

[Klenfo]

My unit turned off itself last time even w/o input signal. It working again after turning on. I would like to know how to fix it, preferably without sending it back. 'Cause I think it may turn off forever and never turn on again. What is the reason for these shutdowns if OPA2140 is not broken?

 

[TP-Wong]

What about units that are not dead, but go into suspend once in a while? This is the case for mine, it turned itself off on it's own like 6-7 times since I bought it, op amp itself is not dead for sure because I am able to turn it on every time this happens.
I already put mine into box and went back to using my older dac, I'm just not sure what to do. If I send it back to seller, the unit doesn't even appear broken (it will turn on and work, it would require like 2 weeks of testing to experience this self-shutdown issue, at least that's about how often this happens to me).

Your unit and @Wolven 's unit is quite special, we never received this kind of report before. How about sending back to us for analysis? I will pay back you shipping fee and send new unit to you. I think 2 units will be enough.

 

[Yuno]

Your unit and @Wolven 's unit is quite special, we never received this kind of report before. How about sending back to us for analysis? I will pay back you shipping fee and send new unit to you. I think 2 units will be enough.

Sure, I just need to figure out how to send to China (never did before).
For shipping should I use address from contact information on webpage? (Add: 26th Jiaomen Road, Huangge, Nansha, Guangzhou, China. ZIP: 511455)

 

[Klenfo]

we never received this kind of report before

Here I wrote about self-shutdown since the unit was buyed https://www.audiosciencereview.com/...c-and-headphone-amp.4967/page-101#post-141572
and shutdowns still continues (not often, but still) and still no info how to fix it....

 

[Wolven]

Your unit and @Wolven 's unit is quite special, we never received this kind of report before. How about sending back to us for analysis? I will pay back you shipping fee and send new unit to you. I think 2 units will be enough.

I would like to send it as well, but have to figure out how. So, can I just send it to the address above?

 

[azxswq]

My experience with my purchase from Massdrop on Feb. 26th is so far flawless.

Great unit. Get one.

 

[TP-Wong]

Yes, I too want to know. My unit has been off easily 7-8 times since I bought it. I have used headphones for less than 30 hours, and I'm not willing to test and push my luck.

Thank you very much!
I sent address to you and @Yuno already.

 

[TP-Wong]

My unit turned off itself last time even w/o input signal. It working again after turning on. I would like to know how to fix it, preferably without sending it back. 'Cause I think it may turn off forever and never turn on again. What is the reason for these shutdowns if OPA2140 is not broken?

We need time to wait for the 2 unit from Yuno and Wolven. I think it won't too long for our analysis.

 

[gvl]

@TP-Wong, this is unrelated to the issues being discussed here, but I have a failed DX7s and would like to purchase a replacement main board shipped to the USA, can Topping accommodate such a request?