Review and Measurements of Topping DX3Pro DAC and Headphone Amp

[Veri]

I think the PSUs above are a bit overkill... They cost more than the device itself..... A lot more...

The meanwell listed above even measured seems fine, if an upgrade is wanted. Even the upgrade is arguably unnecessary... but I could understand it just to be safe

 

[finneybear]

https://item.taobao.com/item.htm?spm=a1z09.2.0.0.67002e8dlkDxJw&id=520731611524&_u=22esj2rk8d3a

LM317 most likely. I opened it up but couldn't reach the reg. Haven't given it much interest. The shop is always solid on it's products and design. When I connected it the headphone amp got quite a big bump in lower frequencies compared to the original switching supply.
and it has 2 DC ports in the back so I keep both my units connected and can fast switch between them to do listening comparissons.

Thanks for the link. Looks an ideal supply for DX3. I will get it instead of building one myself. I will swap in a LT1085 and upgrade the output caps to hybrid polymer.

I also notice they are selling USB power supply/filter. Will try it, too.

 

[finneybear]

I had typed a nice post for you.. but you're not worth the time. I'd advise you to actually contribute something instead of nagging.

As for the A/B testing.

Have a good day with your hobby of knowing it all and finding posts to nag on.

OK, it goes this way:

1. My memory may be wrong. I saw Amir was testing stock SMSP against a lab power supply? Lab power supplies are mostly SMPS as well.

2. Components in DX3 are fed by DC-DC converters, 54331. 54331 works at the frequency 750KHz. This means it needs current feed around 750KHz interval.

3. 750KHz is a fairly high frequency for most power supply. To meet 54331's current demand, you need good capacitors to feed the current.

4. The capacitor needs to have enough current reserve and most importantly, it will work well at 750KHz.

5. This capacitor in DX3 is not only fairly small - 100uf. And a no brand name one, who knows how it performs at 750KHz?

6. The stock power supply is small. It may not have any big capacitor at the output side to feed current to DX3.

7. Mean well SMPS is better cause at least it has decent output capacitors.

8. Power supply's job is to feed this capacitor on time. The easiest indicator is the load regulation performance of the power supply. It's about how well the regulator can keep the capacitors current reserve at a consistent level. Linear power supply is better here. Still, linear power supply works in a frequency much lower than 750KHz. Again, you solve the problem by putting enough capacitors at the output side of the power supply. In this case, solid polymer caps are better for their excellent high frequency performance.

9. Good power system design engineering is important. Good engineering comes before good measurements because measurements may not cover certain important performance aspects. Sure, there are power system test means. AP is not for testing power system.

10. Many people have misunderstanding on bass performance. Take strong and fast drum beats as an example, the combination of harmonies may look more like square waves (even after the brick wall 22KHz filter on the recording device). I.e. There are still mid high frequency components in a drum beat. Square waves have a huge demand on the power supply though we do not have any standardized means to test square waves. People have been long testing amps with square waves by observing the result on scope, however.

11. Another thing is speakers usually have lower impedance at low frequencies. This means they will need more current at low frequencies.

12. Hence after power supply upgrade, most people will hear improvements on mid bass right way.

13. So some catches with AP tests - a) AP can only see part of the power systems performance. b) Have you tested the right SMPS against the right LPS? c) AP may have shown the differences yet they are interpreted as of little significance and ignored.

 

[Cidious]

I saw the USB isolators they have but they are quite expensive. I do have interest in the Holo audio one though. The shop is mainly selling stuff that works and they have a good range of measuring equipment themselves. I intend to send my DACs to them and ask them to do some measurements for me. If they are interested. Else I can ask LKS. They are practically located next door and also know what they are doing. Might be more logical than send the DACs out of China.

Another idea for the isolator is

https://m.tb.cn/h.3uLg9xq?sm=6fea54

I own the mk1 version of this brand. I'd say it does the job. But without measurements don't believe my word on it. Don't want to piss off the measurement police. You can have a look into it and try for yourself.

 

[finneybear]

I saw the USB isolators they have but they are quite expensive. I do have interest in the Holo audio one though. The shop is mainly selling stuff that works and they have a good range of measuring equipment themselves. I intend to send my DACs to them and ask them to do some measurements for me. If they are interested. Else I can ask LKS. They are practically located next door and also know what they are doing. Might be more logical than send the DACs out of China.

Another idea for the isolator is

https://m.tb.cn/h.3uLg9xq?sm=6fea54

I own the mk1 version of this brand. I'd say it does the job. But without measurements don't believe my word on it. Don't want to piss off the measurement police. You can have a look into it and try for yourself.

I have noticed this workshop for a while yet have never listened to their products. Their USB isolator seems to be a good comprise IMHO.
Yes, simple noise filtering on power and ground lines will work for most people. Here they replace it with a clean power supply instead.
Theoretically it's a more solid solution.

I have seen designs using FIFO and OCXO to do reclocking, etc. Costs over $1000 a piece. It's a bit too much. The main problem probably is just a computer with a CPU not powerfully enough. Since I know the people who defined the USB specs in the company, someday I will show them all of those crazy devices people created, and see their reactions.

After the power sys mod is done, the next step will be the LPF. It's another main source for weak mid-bass.

 

[Toku]

My two Topping DX 3 Pro purchased last year's November 11th at the AliExpress bargain.
The case color is black. The power supply is always on except for going on a trip.
Initially I experienced sleep problems several times.
However, now the sleep problem does not occur at all when the season becomes midwinter and the room temperature reaches 6 degrees.
The S / N of two DX3 Pro is 1808xxxxxx.
From this, I think that DX3 Pro has some kind of thermal problem.

 

[amirm]

1. My memory may be wrong. I saw Amir was testing stock SMSP against a lab power supply? Lab power supplies are mostly SMPS as well.

My lab supply I use with DACs is linear. I also have an audiophile linear supply I use for testing.

 

[kagwind]

This means they will need more current at low frequencies.

12. Hence after power supply upgrade, most people will hear improvements on mid bass right way.

Thanks. This is what I have been wondering.

On another topic, my unit is "1901".
IF the instability issue occurs on my unit (which I really hope not), it will indicate that it is not batch-related.
But since I am not a daily user and my unit is in my office with central air conditioning, a thermal problem may not occur easily.

 

[pacman]

My two Topping DX 3 Pro purchased last year's November 11th at the AliExpress bargain.
The case color is black. The power supply is always on except for going on a trip.
Initially I experienced sleep problems several times.
However, now the sleep problem does not occur at all when the season becomes midwinter and the room temperature reaches 6 degrees.
The S / N of two DX3 Pro is 1808xxxxxx.
From this, I think that DX3 Pro has some kind of thermal problem.

It's not thermal, Amir cooked the board at 70ºC without problems

Mine runs 4~5 hours/day at about 30ºC - batch 1808 - for 1 month straight

 

[amirm]

It's not thermal, Amir cooked the board at 70ºC without problems

Mine runs 4~5 hours/day at about 30ºC - batch 1808 - for 1 month straight

It could be a bad solder joint in some unit that acts up this way. This is why I love to get my hands on an intermittent one to see if I can force it to fail on demand. But yes, your general comment is correct that the design itself has no thermal issues at all.

 

[rebbiputzmaker]

It could be a bad solder joint in some unit that acts up this way. This is why I love to get my hands on an intermittent one to see if I can force it to fail on demand. But yes, your general comment is correct that the design itself has no thermal issues at all.

Maybe people can post pictures of the boards that have issues, to see if any possible bad connections can be spotted.

 

[amirm]

Maybe people can post pictures of the boards that have issues, to see if any possible bad connections can be spotted.

It is a very difficult unit to open. You need a very long allen wrench to open it.

 

[rebbiputzmaker]

It is a very difficult unit to open. You need a very long allen wrench to open it.

Yes someone mentioned that, 2mm 8in long. They are ebay for less than $10. Probably not the best quality, but good enough to open a case. Not like back in the days when the early made in China tools would strip the first time they were used.

 

[bellyofthebizd]

Ive got one power off with 1808 but i suppose that is power dependant and the device is a bit delicate for underpower with stock charger (fe got a tv blackout when turnig on amp i guess due to big transformer), ive ordered better adapter now(not so fancy but good quality Sunny 15v)

 

[ngs428]

Shout out to SHENZHENAUDIO on Amazon. Great customer service when I returned my DX3 Pro. I would not hesitate to buy from them. Just throwing that out there if anyone is looking to buy from them.

 

[david99]

Hi All,

I received my unit last week - 30. January, used it only for few hours. Over weekend I was not using it as I was not at home today I came back home started to listen spotify everything was working then was going to take some water to kitchen and when came back DX3 was in standby mode immediately thought it is dead and it really is cannot wake it from standby anymore. My serial number is 1812593025. Contacted seller on aliexpress very interested how they are going to sort it out.

David

 

[MusicNBeer]

Got mine last week as well. It's a 1901. Running perfectly. I was going to send it back based on the problems but kept in once I opened it and hooked it up. This thing performs awesome as a digital preamp. It really could be used with a $10K amp speaker combo with zero system degradation.

 

[yue]

Hi All,

I received my unit last week - 30. January, used it only for few hours. Over weekend I was not using it as I was not at home today I came back home started to listen spotify everything was working then was going to take some water to kitchen and when came back DX3 was in standby mode immediately thought it is dead and it really is cannot wake it from standby anymore. My serial number is 1812593025. Contacted seller on aliexpress very interested how they are going to sort it out.

David

@amirm is looking for buying a fully dead one. Don’t rentrun to seller. Please contact him and he will buy it from you.

 

[david99]

@amirm is looking for buying a fully dead one. Don’t rentrun to seller. Please contact him and he will buy it from you.

Thanks for letting me know. If this is really the case I will cancel return.

@amirm I will send you PM.

David

 

[NTomokawa]

The apparent failure rate of this product is alarming.

However, these failures seem display the same symptoms, namely the standby/sleep issue. Perhaps this points to a single point of failure.

If this is the case, then a redesign would probably fix the issue.

Let's hope Amir can get a few "dead" DX3 units and figure out what fails.