Problem: Intermittent RF-like interference with USB audio streaming
Equipment: Galaxy Note2 connected via USB (OTG cable) to iBasso D-Zero
When streaming music (esp. Pandora), intermittently, annoying static will be introduced for a period which can vary from 5-30+ seconds. Sometimes, it will stop on its own and return to normal. Other times, I have to unplug the USB cable and reconnect. That will usually give me several minutes of clear music, but eventually, the interference/static problem recurs. When I have my headphones on, occasionally, the static jumps from one channel to the other! It reminds me of high-pitched radio interference; but, after much troubleshooting on my part, including Internet research, I have not been able to pinpoint a cause. If I connect the D-Zero to my laptop via standard USB cable, I can listen to streaming audio with no static. Similarly, if I plug my headphones directly into the Note2’s mini-jack, the music streams without incident. I also tried connecting the D-Zero to my wife's Galaxy S3 - no static or other interference problems at all!
I wrote to iBasso asking if there could be a shielding problem with the USB audio cable, but they believe that the interference is most likely being generated by the phone itself. After my own testing, it seems likely that the Note2 is the culprit, but what could be causing the interference? An app? I have tried shutting down Bluetooth, GPS, Power Saving, Tasker, AVAST, and pretty much every other app that seemed a potential candidate. One post I read suggested that the pen stylus could be causing electromagnetic interference. Hmmm... I don't think that the problem is being caused by any other devices in my house (e.g., cordless phone, router, Roku), but I can't be certain. I have tried disconnecting everything I can think of; but, thus far, the only antidote I have found is to unplug the USB audio cable and reconnect it.
I should mention that I have a ZeroLemon battery installed in this Note2, but it seems unlikely that it could be generating RF-like interference and only to the USB audio output stream.
I am at wits end and would sure would appreciate help from this forum's experts. Any ideas or suggestions as to possible causes?
Try changing to "WCDMA only" mode for network settings....so far I find that causes the least amount of interference.