Topping DX5 II

[audiofun]

Because I tried that Bloc Party track from your link through my D50 III/L50 stack -- L50 was set to Medium gain, 12 o'clock on the volume knob, headphones plugged into the 6.35mm jack, TRS cables used to connect DAC to L50 -- and nothing happened, not even starting at minimum then raising it, going a bit past 12 o'clock. It just kept playing. Is that because the DC protection you have said the L50 possesses isn't working properly or is it simply not being pushed into protection mode under my test conditions? Would that also mean that the DX5 II's DC protection isn't working properly or is it simply not being pushed into protection mode under certain conditions/configurations (JIW mentioned it does and doesn't relay click depending on the parameters)? My understanding is that you have seen evidence that the necessary circuit is there.

“ you are holding it wrong”

Well just kidding. You may use the wrong input of your L50 to trigger that. Remember that a headphone amp has input stage, and may be AC or DC coupled. In terms of L50, inputs may be AC coupled, which means it filtered out the DC in your DAC output physically using a capacitor. So your unit is fine. You may only be able to trigger DC protection using DC coupled inputs.

To correctly trigger it you can try to use DC coupled inputs, or short the capacitors to make AC coupled inputs DC coupled. In this case the DC signal will be fed to the unit, and the unit will guard against it.

DX5II, however, does not have capacitors between dac section and amp section similar to your setup has. So any DC contents in your music will be fed directly to your amp, similar to a DC coupled input case. If DC protection is not implemented, you may burn your headphones.

 

[audiofun]

DC issue has to be defined.
It's one thing that a device outputs DC (that's a major NO ) and it's another thing to be able to play DC content included in some (badly made) tracks.

We're probably talking about the later here, an RME-like optional filter could be handy there.

Yes. I have been using very careful words from the beginning but I felt people are still overreacting it. Lemme clarify it again:

The DC issue I raised here is the unit will not protect your headphones if your music has DC contents.

If you are not playing music that is poorly mastered, your headphones are safe.

Most Topping products released earlier have DC protection feature, which shuts off headphone outputs if you are playing music with DC. This feature is missing in DX5II.

 

[audiofun]

To my knowledge this has been brought up by one owner and has not been verified yet.

Every one can verify that. Just play the track on YouTube, using max volume. If the unit doesn’t shut the headphone outputs off, the dc protection is not triggering.

Beware this test may damage your headphones. Use headphones you are about to throw away for the test.

 

[plant550]

Every one can verify that. Just play the track on YouTube, using max volume. If the unit doesn’t shut the headphone outputs off, the dc protection is not triggering.

Beware this test may damage your headphones. Use headphones you are about to throw away for the test.

Max volume on the amp? Why would anyone ever turn their amp that loud.....

I don't get any issues when I try on my unit

 

[audiofun]

Max volume on the amp? Why would anyone ever turn their amp that loud.....

I don't get any issues when I try on my unit

You missed the logic here. If it’s not triggered at max volume then it won’t trigger at lower volume.

And what do you mean by not getting issues? If the music keeps playing at max volume it means protection is not kick in.

 

[plant550]

You missed the logic here. If it’s not triggered at max volume then it won’t trigger at lower volume.

And what do you mean by not getting issues? If the music keeps playing at max volume it means protection is not kick in.

So if the issue only exists at max volume and you have to sacrifice a pair of headphones what’s the value here? Do you have a test which will trigger at volumes people actually listen with

 

[Joachim Herbert]

If the unit doesn’t shut the headphone outputs off, the dc protection is not triggering.

I just listened to that (awful) track via an RME ADI-2/4 via speakers and headphones. No DC detected. I would not blame the DX5/II for not detecting DC either.

I had been using the ADI-2 DAC before and observed two or three DC events in the course of five years, effectivly muting the output.

So I wonder : No dc protection or dc protection not triggered?

Edit: It did not trigger at listening level. Why should I use maximum level for this? I do not listen at maximum level.

 

[JIW]

I just got mine today after ordering it on Audiophonics on 25. June. It shipped on 27. June due to inventory on 26. June. Here is a list of things that may be interesting to some.

Menu button functions like return. No need to scroll all the way down. Menu from home opens the menu where it was last used before having returned to Home Screen.

The language setting is flipped in language. It shows English in Chinese letters (as far as I can tell since I don't speak it and only looked at Wikipedia titles in Chinese zh) as selected when using English and shows Chinese in Latin letters when using Chinese.

Display shows kHz improperly as KHz.

No issues with maintaining USB connection on macOS. No workarounds needed as for other devices with XMOS XU-316.

Slight pop in headphones while turning on before relay clicks. Even when HPA is not selected. It might do the same on the line-outs.

High gain is indicated by GAIN being displayed below dB in normal Home Screen. Slight pop on switching but no audible relay click.
Audible relay click when HPA is selected. No interruption or pop during playback.

With no audio signal, slight pops on sample rate changes seemingly independent of volume setting. Scaling with gain as is expected. No noticeable pops when changing sample rate with music playing. Only muting for 1-2 seconds.

A bit front heavy. Resting hand on top and pushing buttons can lift rear.

All on level meters does not include VU.

1 dB step volume jumps to nearest full dB when changing volume from previously selected half dB value, i.e. x.5 dB.

Balance works by attenuating one channel rather than boost, e.g. R 2.0 dB is L -2.0 dB.
View attachment 461070
View attachment 461071View attachment 461072

Edit: I sent an email to Topping about the language issue.

Topping has replied. The languages are displayed as such so they can be changed by someone unfamiliar with the unit without a factory reset.

The difference in language display is an intentional design. If a child or someone unfamiliar with the device accidentally changes the language, the unique display format helps users identify and switch back to the correct language without needing to perform a full factory reset.

 

[audiofun]

So if the issue only exists at max volume and you have to sacrifice a pair of headphones what’s the value here? Do you have a test which will trigger at volumes people actually listen with

Your reading comprehension needs to be improved. It should of course trigger at lower volume — as discussed in the referred thread, A30Pro trigger at no gain at 12 o’clock volume knob, which is a fairly normal listening volume. But if it doesn’t trigger at max volume it’s not triggering at lower volume. And a max volume test is the best test to reproduce.

You can test it without using headphone. Just plug a headphone jack in without headphone connection. If you don’t hear relay sound when turning volume from -50db to 0 db, your unit does not have that feature properly implemented.

 

[audiofun]

I just listened to that (awful) track via an RME ADI-2/4 via speakers and headphones. No DC detected. I would not blame the DX5/II for not detecting DC either.

I had been using the ADI-2 DAC before and observed two or three DC events in the course of five years, effectivly muting the output.

So I wonder : No dc protection or dc protection not triggered?

RME has software dc filter in the menu. Your unit may already have that feature on. So the DC is already filtered digitally from your music with RME’s DSP technology. So there is no need for the hardware protection to kick in. Otherwise it should trigger.

The RME manual even have a full chapter mentioning that topic, using the same track as example. Go ahead and read that. If you play with DC filter off and protection is not kick in, talk to RME. Your unit is broken.

Again this is a complex topic and varies from product to product. If you are not that deep into tech you may easily reach to the wrong conclusion.

 

[JIW]

Where does Topping state that?

The white version is expected to be available again on Audiophonics from 18-25. July. It is in stock in silver.

I asked Audiophonics about the delay being caused by a factory defects having to be addressed and it originating from them. This is the reply I got.

We confirm that this information does not come from us and does not appear to be justified.

The delay in the restocking time is simply due to the fact that this product is out of stock at the manufacturer.

The manufacturer never informed us of a manufacturing defect.

 

[Joachim Herbert]

Again this is a complex topic and varies from product to product. If you are not that deep into tech you may easily reach to the wrong conclusion.

Go figure.

 

[plant550]

Go figure.

It's so complicated that multiple people have tried and found no such issue....but only 1 person has

 

[audiofun]

It's so complicated that multiple people have tried and found no such issue....but only 1 person has

You clearly verified my point—DC protection is not triggered on your unit, when playing not properly mastered music content. So I am not the only person. You are with me now.

Go figure.

Till now only two people test other products and don’t see it being triggered in their other units, one with topping L50 the other with RME, because their products have different tech properties. @ziggurcat ’s L50 has AC coupled input. Your RME has software DC filter and you didn’t turn it off when performing the test. In both cases, the DC content is filtered from your music, so the music is free from DC, and no need for DC protection to kick in. DX5II is not one of these products that can filter DC. So if protection is not kicking in, your headphone might be destroyed

So if you are testing with DC filter on in the menu, clearly you are not doing the test in the right way. And this is verbosely documented in the RME manual—they are even using the same track as example. Perhaps you need to read the instructions first?

 

[audiofun]

I am not going to reply to posts related to the DC protection issue further. I have made my points clear.

I don’t understand why I mentioned DC protection is not correctly implemented in the unit then people suddenly became mad at me. What the heck is going on?
I don't understand what's the intention behind all those comments? Especially from @plant550, who actually verified the feature is missing on his unit and proved my point.
It's quite normal product A has one feature but product B doesn't. People can choose their products based on whether that feature is important to them or not.
Why saying product B doesn't have certain feature implemented can lead to such unhealthy discussion?

 

[Toni71]

I think it's up to Topping to clear things up. As a non-tech, I greatly appreciate your findings. My speakers are expensive, too expensive to risk using with faulty hardware. I don't know if they are at risk. Maybe not, I'll wait for more information. Perhaps, I better invest some more in another brand in Europe.

 

[sportklotz33]

Topping has replied. The languages are displayed as such so they can be changed by someone unfamiliar with the unit without a factory reset.

This is what came to my mind when I saw it on my unit the first time. Not sure why we bordering Topping with such "little unpleasant things".

 

[audiofun]

I think it's up to Topping to clear things up. As a non-tech, I greatly appreciate your findings. My speakers are expensive, too expensive to risk using with faulty hardware. I don't know if they are at risk. Maybe not, I'll wait for more information. Perhaps, I better invest some more in another brand in Europe.

Oh you misunderstand the topic. We were talking about DC protection for headphones in the built in headphone amplifier.
Your speakers should be protected by your external amplifier (if it's active then internal amplifier) connected to this product, not this product itself.
It's quite normal for a DAC to output DC if the music has DC. Amp is responsible to implement all kinds of protection (DC, overcurrent, overheating, etc).
Most DACs in the market are DC coupled, and do not have the protection feature.

 

[Sokel]

Oh you misunderstand the topic. We were talking about DC protection for headphones in the bundled headphone amplifier.
Your speakers should be protected by your amplifier (if it's active then internal amplifier), not this unit.
It's quite normal for a DAC to output DC if the music has DC. Amp is responsible to implement all kinds of protection (DC, overcurrent, overheating, etc).
It's likely 99% of DACs in the market do not have the protection feature.

Some amps do, some don't.
Hypex NC250MP for example will allow up to 12VDC before protections kick in.
And that 12V will of course be amplified and...

It's buyers duty to read fine prints or just ask.

Edit: an another, as I write all the time.
I cannot even imagine someone who spends for audio gear does not invest a small amount to get a DMM and learn how to use it for simple sanity measurements.
EVERY device must be checked for DC right out of the box, before entering the chain.

 

[Zipper]

How polarizing a budget DAC can be. This thread already has over 50 pages in a relatively short time. I really hope Topping will address these issues soon and provide some clarification. The disappearance of PEQ profiles is one thing, but the lack of DC protection is a whole different story. I hope these problems can be fixed through a firmware update or, at the very least, through a straightforward manufacturer recall. Otherwise, the search for a good DAC/amp in a similar price range will have to continue. The DX5 II really is impressive in terms of specs and pricing - without the bugs obviously.