When troubleshooting a buzzing noise from my Windows laptop while listening on Bluetooth headphones, it made me curious why there was even an analog signal being produced. I only get this high-pitched noise when connected to my laptop, the headphones sound great when connected to other sources.

I am looking for some insight into when a possible analog signal is being created, and why. Is it possible that the audio drivers are accommodating a process which creates an analog signal that it must mix in with the other audio sources? That doesn't make much sense to me though. I've disabled all the mics, all other sound outputs except my headphones. Is it possible that my audio driver will always produce an analog signal to accommodate my laptop's headphone jack?


closed as off-topic by ThreePhaseEel, PeterJ, Chupacabras, Sparky256, Voltage Spike Dec 27 '17 at 5:26

This question appears to be off-topic. The users who voted to close gave this specific reason:

  • "Questions on the repair of consumer electronics, appliances, or other devices must involve specific troubleshooting steps and demonstrate a good understanding of the underlying design of the device being repaired. See also: Is asking on how to fix a faulty circuit on topic?" – ThreePhaseEel, PeterJ, Chupacabras, Sparky256, Voltage Spike
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  • 3
    \$\begingroup\$ There is no way to get an analog signal through USB, and it is astronomically unlikely that your system connects a DAC to a ADC just to transmit audio digitally. \$\endgroup\$ – Ignacio Vazquez-Abrams Nov 28 '17 at 17:29
  • \$\begingroup\$ Since I'm connecting via a bluetooth device, is USB related to the issue? Also, what do you think would cause buzzing if there an analog signal is not being produced at any point? \$\endgroup\$ – AnotherDeveloper Nov 28 '17 at 17:32
  • \$\begingroup\$ There are two ways that a Bluetooth transceiver connects to a system: USB and UART. And UART is only used in embedded systems and SoCs. \$\endgroup\$ – Ignacio Vazquez-Abrams Nov 28 '17 at 17:34
  • \$\begingroup\$ The buzzing would be caused by a digital issue, either in the OS/software or in the transceiver. \$\endgroup\$ – Ignacio Vazquez-Abrams Nov 28 '17 at 17:36
  • \$\begingroup\$ I'm way off track then, obviously I'm knowledgeable in this area. Thanks for the feedback, no pun intended. :). \$\endgroup\$ – AnotherDeveloper Nov 28 '17 at 17:38

The analog signal only comes into existence in your headphones. Full stop.

So, since the headphones work with other devices: you haven't successfully eliminated all programs that add noise to your audio output. That's a pure software/usage problem, and unrelated to electrical engineering.

Bluetooth is standardized. Either audio transmission works, or it doesn't.

  • \$\begingroup\$ Do you know why I only have this issue when connecting to my laptop? Maybe the problem is how my headphones are interpreting the digital output from the laptop? \$\endgroup\$ – AnotherDeveloper Nov 28 '17 at 17:36
  • \$\begingroup\$ No. Stop looking around. Your problem is in software running on your PC. Not anything to do with Electrical Engineering \$\endgroup\$ – Marcus Müller Nov 28 '17 at 17:37
  • \$\begingroup\$ @AnotherDeveloper more likely the laptop is radiating EMI that is being picked up by the headphones. \$\endgroup\$ – Trevor_G Nov 28 '17 at 17:38
  • \$\begingroup\$ @MarcusMüller Ok, if you are confident that the buzzing, high-pitched noise is a software issue, my question doesn't belong here. Sorry. \$\endgroup\$ – AnotherDeveloper Nov 28 '17 at 17:41
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    \$\begingroup\$ @AnotherDeveloper as Trevor said, it might be interference by the laptop, but that would vary with distance/relative position to laptop, whereas the payload audio wouldn't. Since you're not mentioning that: yes, my stochastic view on this is: it's software. \$\endgroup\$ – Marcus Müller Nov 28 '17 at 17:42

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