[SOLVED] Very distorted when NOT in cover view

[Reddo84]

Whenever I am not in cover-view, the sound is very distorted. Not always as bad as in the following video, but bad enough. Please note the problem is completely gone, when I switch to cover view. 

The problem persists even if I disconnect the screen, including from power. I'm using 8.0.2 to be able to use the toggle button, but the problem is the same in 8.1.1. I'm using a sine tone instead of music to not trigger YouTubes upload filter. 


[video=youtube]https://youtu.be/n0Unwt9BKNs[/video]

[TheOldPresbyope]

@Reddo84

When you say "even if I disconnect the screen", does this include changing the Local UI Display setting to OFF in the System Config panel?

Regards,
Kent

[Reddo84]

When you say "even if I disconnect the screen", does this include changing the Local UI Display setting to OFF in the System Config panel?

Hi Kent, that works as well to get rid of the distortion, even if the screen stays connected and switched on. I go into such detail because I want to bring across the point that the problem absolutely cannot lie in the screen itself or its cabling.


Edit: If I may make a guess - the problem might somehow be connected to that circle-shaped progress bar. I sometimes have very minor clicks and pops even in cover-view the moment the artwork changes. So maybe the problem is connected to the constantly changing progress indicator.

[philrandal]

Raspberry Pi model and RAM? The devil may be in the detail.

[TheOldPresbyope]

When you say "even if I disconnect the screen", does this include changing the Local UI Display setting to OFF in the System Config panel?

Hi Kent, that works as well to get rid of the distortion, even if the screen stays connected and switched on. I go into such detail because I want to bring across the point that the problem absolutely cannot lie in the screen itself or its cabling.


Edit: If I may make a guess - the problem might somehow be connected to that circle-shaped progress bar. I sometimes have very minor clicks and pops even in cover-view the moment the artwork changes. So maybe the problem is connected to the constantly changing progress indicator.

Ah, but telling us the problem goes away when the Local UI Display setting is OFF is the vital clue. 

If it's on, then the Chromium browser is running in moOdeOS and code is rendering the UI and the Allo Sparky's GPU is generating HDMI signals based on it. 

I don't know the Allo Sparky but according to their website it uses a PowerVR SGX544 GPU. All Raspberry Pis use Broadcom GPUs. This suggests to me the two products use different video drivers.

AFAIK, no one has reported a comparable issue with a Raspberry Pi-based moOde player. This suggests to me that there is some digital crosstalk going on between the display subsystem and the USB/audio system in the Allo Sparky/USBridge-based player. I have no way of testing this supposition.

I think you need to bring this issue to the attention of Allo and ask them what mitigation strategies there may be. 

Regards,
Kent

[Tim Curtis]

Audio glitches are almost always caused by something external to moOde software for example bad power supply, electrical or RF interference, network issues, hardware issues bad audio files etc.

[Reddo84]

When you say "even if I disconnect the screen", does this include changing the Local UI Display setting to OFF in the System Config panel?

Hi Kent, that works as well to get rid of the distortion, even if the screen stays connected and switched on. [...]

Ah, but telling us the problem goes away when the Local UI Display setting is OFF is the vital clue. 

If it's on, then the Chromium browser is running in moOdeOS and code is rendering the UI and the Allo Sparky's GPU is generating HDMI signals based on it. [...]

Hi Kent, 

thanks for the insight, I'll get into contact with Allo about this (once more, this time linking this thread and my video). But if I'm not mistaken, my Allo USBridge Signature runs a standard RaspberryPi 3+ Compute Unit (@philrandal) including the onboard GPU. Keep in mind though the unit doesn't produce distorted sound whenever the Chromium Browser is running - when I'm displaying CoverView, everything is fine.

[TheOldPresbyope]

When you say "even if I disconnect the screen", does this include changing the Local UI Display setting to OFF in the System Config panel?

Hi Kent, that works as well to get rid of the distortion, even if the screen stays connected and switched on. [...]

Ah, but telling us the problem goes away when the Local UI Display setting is OFF is the vital clue. 

If it's on, then the Chromium browser is running in moOdeOS and code is rendering the UI and the Allo Sparky's GPU is generating HDMI signals based on it. [...]

Hi Kent, 

thanks for the insight, I'll get into contact with Allo about this (once more, this time linking this thread and my video). But if I'm not mistaken, my Allo USBridge Signature runs a standard RaspberryPi 3+ Compute Unit (@philrandal) including the onboard GPU. Keep in mind though the unit doesn't produce distorted sound whenever the Chromium Browser is running - when I'm displaying CoverView, everything is fine.

Sorry, I missed the "Signature" qualifier. The (original?) USBridge offering I found, https://allo.com/sparky/usbridge.html, discusses Sparky+USBridge+....

Then we're probably down to power supply and power cabling as Tim suggests. 

FYI

1. Enabling the Local UI display (which starts a number of Chromium browser processes) increases the CPU and memory demands on the system generally.

2. The Chromium browser executes different branches of code in the loaded moOdeUI when you switch panels/views so instantaneous CPU and memory demands vary differently as well.

3. CPU demand and power demand are related.

Anyway, I'm out.

Good luck.

Regards,
Kent

[Reddo84]

So I've disconnected the USBridge Sig from my system completely and pieced it back in - bit by bit - checking for distortions after each step (after rebooting). For a DAC, I used a Dragonfly Red instead of my regular miniDSP 2x4 HD. Everything went fine, no distortions. The last thing I changed back to normal was the DAC ... et voilá: With the miniDSP 2x4 HD, the distortions are back full force when not in CoverView. When in CoverView, everything is fine.

Another observation: When I boot up the USBridge Sig and only then connect the screens HDMI cable to the device, the resolution is off (too low), but there's less distortions.

"The Chromium browser executes different branches of code in the loaded moOdeUI when you switch panels/views so instantaneous CPU and memory demands vary differently as well."

Is there more load on the RaspberryPi when:

• not in CoverView?
  
• running a miniDSP 2x4 HD instead of a Dragonfly Red DAC?
  
• the resolution of the screen is higher? 
  

Is the RasPi 3+ inside the USBridge Sig underpowered for the task? I contacted Allo some days ago, still no reaction. I'm trying to get my hands on a regular Raspberry 4 to test this hypothesis. 


Btw, the problem persists with version 8.1.2

[DRONE7]

Is the RasPi 3+ inside the USBridge Sig underpowered for the task?

Should be ok.... I note a post re Pi3 and increasing the swapfile size.
No idea if this is of any help but here is the link..

https://www.diyaudio.com/community/threa...st-7061368