CALLING Topping DX5II DAC Owners - VERY ODD Behavior, Cutting Out

[jmdesignz2]

Hi fellow Topping DX5II enjoyers. I have my first issue crop up and it is a strange one but I one you might also replicate

DX5II is cutting out the signal several times to the XLR line output

The message on the screen was “HP DC Abnormal”

I’m using the USB streaming from a WiiM Ultra via Spotify.

The DX5ii has all outputs active, gain high. I’m running one RCA to my Monolith THX15 subwoofer. The XLR line outputs feed the A70 Pro

The FW is 1.67

HERE IS THE REALLY ODD PART:
So far It’s only when playing”Original Miami Vice Theme” Jan Hammer from Spotify. This happens right around the 14-15 second mark consistently triggers this error. I’ve tried Optical and USB connections from the WIIM Ultra

https://spotify.link/Sai21uB9FXb

See if it happens to you

 

[staticV3]

HP DC Abnormal is a known issue specifically addressed in Topping's various firmware updates.

Try updating your DX5 to the newest FW version: https://www.toppingaudio.com/download/dx5-ii-version-v1-76-firmware-update

As for the behavior, that's not unusual for an Amp with built-in DC protection.

It's a mechanism designed to protect your headphones and speakers from damage caused by shoddy mastering.

If you load that track into an editing program like Audacity or Audition, you'll likely see a DC offset similar to this, precisely at the 14-15s mark: https://www.audiosciencereview.com/...30-ii-review-headphone-amp.36027/post-1870257

That's an "illegal" signal, and it's what triggers the protection.

 

[Berwhale]

Also...

Once you have updated to the latest firmware, you will find a 'DC detect sens' setting under the Advanced menu DX5 II. If updating the firmware on it's own does not solve the issue, you can also try setting 'DC detect sens' to Low.

My DX5 II (with v1.76 firmware and 'DC detect sens' set to High) doesn't go into protection when playing the linked track, so you probably won't need to change the setting.

 

[jmdesignz2]

Also...

Once you have updated to the latest firmware, you will find a 'DC detect sens' setting under the Advanced menu DX5 II. If updating the firmware on it's own does not solve the issue, you can also try setting 'DC detect sens' to Low.

My DX5 II (with v1.76 firmware and 'DC detect sens' set to High) doesn't go into protection when playing the linked track, so you probably won't need to change the setting.

updated the firmware to 1.76 and was able to access that and it fixed the issue

HOWEVER. When in DAC mode the volume control still works

Previously it operated purely in DAC mode
Showing the lock frequency and deactivation of the volume control

 

[Berwhale]

Sorry, I use my DX5 II with powered studio monitors and run in pre-amp mode. I've only had it in DAC mode once when it reset after a firmware update, which I quickly rectified!

 

[jmdesignz2]

OK the second part of the solution to ensure it is in DAC mode is to utilize the "LO ALL" setting and not simply check each of the "LO" outputs.

 

[ziggurcat]

OK the second part of the solution to ensure it is in DAC mode is to utilize the "LO ALL" setting and not simply check each of the "LO" outputs.

I'm not sure why setting it to LO ALL would do anything? Also, according to the changelog, they addressed the volume being controlled in DAC mode in v1.72. There was new FW update made available a few days ago (v1.78), so perhaps that could also help things.

Regarding the DC Abnormal: that's expected behaviour. Topping has made a handful of adjustments to the sensitivity of the DC protection (when the DX5 II launched, the device's DC protection wouldn't kick in at all), and then added the ability for people to make it more/less sensitive, but as far as it showing up on the display, and cutting out the audio being a bug? It's not. And the DC protection typically only triggers when the volume levels are quite high (for example, I have never had it trigger, even listening to any of the examples where it is known to trigger the protection. My volume setting never go above -30dB, but I also use it in preamp mode).

 

[jmdesignz2]

I'm not sure why setting it to LO ALL would do anything? Also, according to the changelog, they addressed the volume being controlled in DAC mode in v1.72. There was new FW update made available a few days ago (v1.78), so perhaps that could also help things.

Regarding the DC Abnormal: that's expected behaviour. Topping has made a handful of adjustments to the sensitivity of the DC protection (when the DX5 II launched, the device's DC protection wouldn't kick in at all), and then added the ability for people to make it more/less sensitive, but as far as it showing up on the display, and cutting out the audio being a bug? It's not. And the DC protection typically only triggers when the volume levels are quite high (for example, I have never had it trigger, even listening to any of the examples where it is known to trigger the protection. My volume setting never go above -30dB, but I also use it in preamp mode).

My FW version didn’t have the ability to set DC sensitivity. That particular Spotify track has some strange signals that trigger it even at normal volume.

Once I updated the firmware and changed the sensitivity it was good

 

[ziggurcat]

My FW version didn’t have the ability to set DC sensitivity. That particular Spotify track has some strange signals that trigger it even at normal volume.

Once I updated the firmware and changed the sensitivity it was good

They were tweaking the DC protection sensitivity in a few different FW updates prior to making it an option in the menu -- v1.49 they introduced the "DC Abnormal" screen notification, v1.62 they adjusted the sensitivity, and v1.72 they adjusted it again (I think v1.72 is where they added the option in the menu, but someone please correct me if I am wrong). DC protection in v1.67 from your OP would have still been passive/behind the scenes, which is why you wouldn't have been able to adjust it in the settings.