Review and Measurements of Topping DX3Pro DAC and Headphone Amp

[DouglasteR]

no

I guess i will conquer my fear and let it be as it is. It´s working afterall

 

[deadchip12]

Am I f*cked?

I purchased a DX3 Pro today without reading this thread. The version I receive starts with 1903, having a hi res audio sticker on top. Reading the manual and warranty card, the output impedance is luckily still < 0.1 ohm (the latest revision is 10 ohm???), but the op amp is now OPA1612 (which seems to be different from the original unit amir reviewed here?).

This is so bullsh*t! Topping change the components that affects the performance without changing the name of the porduct?

 

[JohnYang1997]

Am I f*cked?

I purchased a DX3 Pro today without reading this thread. The version I receive starts with 1903, having a hi res audio sticker on top. Reading the manual and warranty card, the output impedance is luckily still < 0.1 ohm (the latest revision is 10 ohm???), but the op amp is now OPA1612 (which seems to be different from the original unit amir reviewed here?).

This is so bullsh*t! Topping change the components that affects the performance without changing the name of the porduct?

No you are not fucked.
1, It should be opa1612 + opa2140 for the original version.
2, If the unit works fine, it's better than the 2nd version.
3, There is actually nothing wrong in the design of the first version in protection. The original version does have auto shutdown current protection.
so if you want you can return it, but if it works it should be alright.

 

[deadchip12]

No you are not fucked.
1, It should be opa1612 + opa2140 for the original version.
2, If the unit works fine, it's better than the 2nd version.
3, There is actually nothing wrong in the design of the first version in protection. The original version does have auto shutdown current protection.
so if you want you can return it, but if it works it should be alright.

Thanks for the info. This unit costs me quite a lot more money compared to the e10k I returned so just want to make sure I'm receiving what I'm intended to receive.

One thing: I'm not sure I understand when you say opa1612 + opa2140. Does that mean some unit have the 1612 and some have the 2140? On the paper I see here it only says 1612, no 2140. And reading some comments on this thread, the 1612 has some ridiculously high output impedance (~1k ohm) at low frequency? Will that cause a problem or did I misunderstand sth?

 

[JohnYang1997]

Thanks for the info. This unit costs me quite a lot more money compared to the e10k I returned so just want to make sure I'm receiving what I'm intended to receive.

One thing: I'm not sure I understand when you say opa1612 + opa2140. Does that mean some unit have the 1612 and some have the 2140? On the paper I see here it only says 1612, no 2140. And reading some comments on this thread, the 1612 has some ridiculously high output impedance (~1k ohm) at low frequency? Will that cause a problem or did I misunderstand sth?

That's for the original version.
DAC - OPA1612 - OPA2140 - Discrete headphone amplifier (whether opa2140 is controlling the output stage or not is unknown but irrelevant here)
And opamp normally has a few ohm to tens of ohm open loop and less than 0.1 ohm impedance close loop.
I have an original unit working fine but i can't guarantee you that yours won't fail. What I can say is it seems that your unit is perfectly the first version.

 

[deadchip12]

View attachment 30459
That's for the original version.
DAC - OPA1612 - OPA2140 - Discrete headphone amplifier (whether opa2140 is controlling the output stage or not is unknown but irrelevant here)
And opamp normally has a few ohm to tens of ohm open loop and less than 0.1 ohm impedance close loop.
I have an original unit working fine but i can't guarantee you that yours won't fail. What I can say is it seems that your unit is perfectly the first version.

Hmm ok.

Do you see 2140 mentioned anywhere in the booklets that come with the unit? On mine it only says 1612. It's weird if both are inside the dac amp but only 1612 is mentioned.

 

[JohnYang1997]

Hmm ok.

Do you see 2140 mentioned anywhere in the booklets that come with the unit? On mine it only says 1612. It's weird if both are inside the dac amp but only 1612 is mentioned.

there are two booklets.
one is user manual which doesn't have opa1612 or any component, but with graphs and specs.
The other one is warranty card, the opa1612 is shown there but it's just like a promo of different products.
So don't worry, I'm pretty sure yours is the original version.

 

[deadchip12]

there are two booklets.
one is user manual which doesn't have opa1612 or any component, but with graphs and specs.
The other one is warranty card, the opa1612 is shown there but it's just like a promo of different products.
So don't worry, I'm pretty sure yours is the original version.

I see. Thanks.

Fingers crossed this unit doesn't die on me. I hope people who read this review and receive the v2 unit have the option to get refund or some sort because it seems Topping replace the opa chip with something else that pushes output impedance much higher.

 

[Saffuria]

I hope there will be measurements of this new version.

 

[deadchip12]

It's time to give you a feedback about my DX3 Pro failure.
I had a problem with right channel (headphone output) reported and described some time ago, as you can see below:


And the video...


Finally I've got a 1902 version some time ago with some changes like different power supply, new remote (RC-15A), plastic caps on RCA connectors, front LCD protector made from glass and AD8620 instead OPA2140.




It is interesting because my version is 1902 with new remote and power supply. I thought that starting from some point all further versions of DX3 Pro will look like that.
And It seems that AD8620 is not put into all production devices. I've got the following response from Topping:


So, front screen covered by glass seems to be more solid (previously I could bend it under finger's pressure). Remote seems to be better as well (see photos). I have also aluminum remote dedicated to DX7s and self-learning remote bought on aliexpress for everyday usage (blue buttons). I use DX3 Pro as a preamp so I wouldn't like someone from my family (even me) to accidentally switch it to DAC mode and blow my apartment

Regarding AD8620 - I don't have any good headphones and I can't confirm quality differences. I put some cheap in-ear headphones and dac was playing for tens of hours to make load test. Everything is working well so far.
I also don't have a long 2mm hex wrench to confirm if AD8620 was install in manufacturing process or manually but at least I can confirm that indeed it sits inside (I could pull board a little and take a photo).

To summarize I would like to say that Topping Service is really good. I bought my unit on aliexpress but decided to replace it directly via Topping. They sent new unit via DHL so I got it after about 5 days. The only disadvantage is that I had to clarify for customs it was a warranty replacement, not new purchase. Finally they released it from duties. They're providing really good service.

This is weird. I got my unit today. It says 1903xxx on the box. The booklet says OPA1612 and <0.1 ohm output impedance so I assume it's still the same chip instead of AD8620. The remote says RC-15. But I got plastic caps on RCA connectors. So is this still the original version compared to yours which is the newer version with the new chip? Pretty confusing.

 

[JohnYang1997]

Wait a minute. Probably there are three versions?
opa1612+opa2140+discrete 0.1ohm
opa1612+ad8620+discrete 0.1ohm
opa1612+tpa6120a2 10ohm (official V2)

 

[DouglasteR]

I will check mine later today.

 

[Gray]

actually nobody opened his V2 yet to confirm which chips are implemented.
I only see in the manual it's <10ohm.

Unfortunately I don't have a hex key that's that long to open it..

 

[DouglasteR]

Yep, mine is 0.1ohm as well.

 

[AresHarvest]

I've been searching for info about the new version. Can't seem to find much. Is the output impedance really 10 Ω? If true, that's strange because it's a step backward.

 

[Patrick1958]

I've been searching for info about the new version. Can't seem to find much. Is the output impedance really 10 Ω? If true, that's strange because it's a step backward.

And a big disappointment for people who bought if for use with low impedance headphones.

 

[Jimmy]

10 ohm output impedance isn't such a big deal, unless you use IEMs, and TPA6120 isn't bad, it's just that the chip manufacturer recommends using an output resistor to avoid possible oscillations with capacitive loads.

The problem here is that it seems that in the first version they didn't use headphone protection circuitry, and for whatever reason the unit was prone to failure, so instead of improving on the original design they replaced it with a different solution that while decent has nothing that sets it apart from other competing products.

I said it in a previous post, I believe that there's nothing wrong with external help/consultancy when designing a product, and if THX licensing isn't too expensive some manufacturers should think about it instead of investing resources reinventing the wheel.

 

[captainsmart]

I have a 80Ohms DT770 and cannot in the slightest hear any difference between V1 and V2.

 

[AresHarvest]

10 ohm output impedance isn't such a big deal, unless you use IEMs

I do use several pairs of IEMs, ranging from 15 to 45 ohms. This is why it's a concern of mine.

 

[g_t_j]

If headphone output is raised from 1Ω to 10Ω, then the difference will only be audible with very sensitive iems, usually under 10Ω such as balanced armature configurations, multidriver implementation with crossovers etc.

That was the case with the original crowd-funded Hiby R6 DAP. A flaw that was later remedied with the release of a ''Pro'' version of the R6. In that original R6, users have reported that the higher output impedance of the player was alternating the sound signature of their iems and that an iFi ΙΕmatch was an essential link in the chain.

However, here we're having to do with a desktop orientated solution and therefore, I don't think that many users of the DX3 are going to use their desktop rig with iems, let alone with that low impedance ones such as the Andromedas.

Curious to know if anyone has tried DX3 V2 with an iem like the Andromeda or Noble Kaiser.