[SOLVED] Very distorted when NOT in cover view

[Reddo84]

I can't wait to hear if the miniDSP is susceptible to this noise when coupled to a stock RPi.

That could take some time, I'm not paying top dollar for a RPi just to try this out, so I'm looking for a good offer for a used one. 


In the meantime, I have pulled apart my system completely and tried some more things, with headphones connected to the DACs (with 8.1.2):

• When the miniDSP 2x4 HD was just connected to the USBridge Signature the problem persists anyway.
  
• When the USBridge Sig was connected to a Steinberg UR12 Audiointerface DAC, the distortions sounded different, but were very present nonetheless. Please note that the Steinberg is powered through USB, so no power supply issues there.
  
• The distortions from the Steinberg didn't react to the USBridge Sig being powered by its stock power supply, another 5V power supply, my custom battery setup or a 5V powerbank.
  
• The distortions from the miniDSP didn't react to the USBridge Sig being powered as described above. Also powering the miniDSP straight from a 12V motorcycle battery didn't change anything.
  
• Grounding the USBridge Sig through its dedicated grounding connection didn't change anything.
  
• Trying different USB-cables from the USBridge Sig to the DACs didn't change anything.
  
• Starting a track stored locally on the USBridge Sig and then disconnecting the Ethernet-cable didn't change anything. The distortions were still present.
  

So ...

• I pulled apart my system and made sure all the cables were at the most possible distance from one another. I think cable interference can safely be ruled out.
  
• Even powering the whole setup - the USBridge Sig as well as the DAC - straight from batteries didn't change anything. I think power supply can safely be ruled out.
  
• Trying different cables didn't change anything. I think faulty cables can safely be ruled out.
  

This reinforces in my mind that the interference is being generated by the Javascript being processed in the CPU and the results then processed in the GPU-related subsystem

I think so, too. Is there any way to mend this? I am still convinced that it is the circular track-progress indicator that is causing the problem. Sometimes, it freezes for a couple of seconds and when it comes back to life again, this is always accompanied by a burst of distortions. 

Another thought: The Audioquest Dragonfly Red - the only DAC so far not showing this problem - is a second gen smartphone DAC, specifically engineered to not drain the smartphones battery as fast as its predecessor. Maybe the Dragonfly Red doesn't put as much strain onto the USBridge Sig ... what could be learned here?