I have a weird problem.
Everything works fine  except the headphone output: suddenly it started to produce rather  distorted sound, like a heavily overloaded signal is padded with a −30dB  limiter. I have the latest firmware (2.00.72.87), so it can't be updated or  flashed over. I tried to power-cycle and factory reset — that didn't  seem to have any effect.
Any ideas?

RX s/n 4VFZK8L0011171
TX1 s/n 4VEZK8N001951
TX2 s/n 4VEZK8N001642
Case s/n 4VFZK8L00215KZ

Hi, Dyor. Thanks for reaching out, and we're sorry for the inconvenience. We'll have your concern forwarded to the related team for feedback. We'll keep you posted.

Hi there. We need to verify more details to support the analysis. Kindly confirm the following information:
1. Does the issue also occur when the DJI Mic is used alone? If not, kindly confirm the specific model of the device used with it that shows the issue.
2. What is the approximate frequency of this abnormality?
3. Have you tried using other headphones to see if the issue remains? If not yet, please try and test again.
We will be waiting for your update. Thank you.

DJI Tony Posted at 5-17 08:39
Hi there. We need to verify more details to support the analysis. Kindly confirm the following information:
1. Does the issue also occur when the DJI Mic is used alone? If not, kindly confirm the specific model of the device used with it that shows the issue.
2. What is the approximate frequency of this abnormality?

1. It happens regardless of interaction with other devices over any interface, be it a minijack, USB-C, or Lightning, or standalone.
2. It is now a permanent situation. Something (not sure what) probably caused some circuitry damage — even though I did nothing that would cause it: no wrong connections, no drops, no overheating, no humidity, nor anything else.
3. I tested it with several different headphones: RY4s+ 32 Ohm, Sony MDR-7506, Shure SRH440, Beyerdynamic DT 240Pro, and some others.

Dyor Posted at 5-17 08:51
1. It happens regardless of interaction with other devices over any interface, be it a minijack, USB-C, or Lightning, or standalone.
2. It is now a permanent situation. Something (not sure what) probably caused some circuitry damage — even though I did nothing that would cause it: no wrong connections, no drops, no overheating, no humidity, nor anything else.
3. I tested it with several different headphones: RY4s+ 32 Ohm, Sony MDR-7506, Shure SRH440, Beyerdynamic DT 240Pro, and some others.

Hi, Dyor. Thanks for the update. These additional details will be forwarded for further investigation. Thank you.

DJI Tony Posted at 5-20 03:14
Hi, Dyor. Thanks for the update. These additional details will be forwarded for further investigation. Thank you.

Any chance of replacement (especially considering that I'm in Russia)? Not that it's that critical but sometimes I may need clean headphone monitoring on the RX (like, when using camera without a headphone output).

Dyor Posted at 5-20 03:16
Any chance of replacement (especially considering that I'm in Russia)? Not that it's that critical but sometimes I may need clean headphone monitoring on the RX (like, when using camera without a headphone output).

We will communicate this with our related team for confirmation first.

Dyor Posted at 5-20 03:16
Any chance of replacement (especially considering that I'm in Russia)? Not that it's that critical but sometimes I may need clean headphone monitoring on the RX (like, when using camera without a headphone output).

Hi, Dyor. Can you share a sample audio recording where the issue is audible and update it on this link? Thank you.

DJI Tony Posted at 5-22 05:15
Hi, Dyor. Can you share a sample audio recording where the issue is audible and update it on this link? Thank you.

Sorry for the delay (last week's work schedule was quite tight), I uploaded the file.

The recording is separated with 1 kHz tones: tone, headphone output malfunction with normal speech, tone, headphone output with whsiper, tone, headphone output to line input, tone, normal line output.

When recording the first and the second sections (headphone out to headphones), I set the RX headphone output to the maximum, and also I boosted the first section, but that is done so that anything would be heard at the recording. I set the Zoom H-1 built-in mic level to 100%.  Mind you that nothing was overloaded at all, quite contrary. Noteworthy, breaths and whispers sound rather fine.

Third section, headphone out to line in: RX headphone out set to 0 (middle), Zoom H-1  line in set to 20%. When I connect a recorder  to the RX headphone out with the stock 3.5mm cable (straight, not angled), there is no distortion but just dropped levels and clicks. Looks like some kind of protection, probably has something to do with impedance.
Fourth section the RX line output to Zoom H-1 line input: everything is perfect, the Zoom H-1 input level was set to 25%, the RX line out gain was 0 (middle).

Before today, I never plugged in headphone out to a camera or a recorder line input even by mistake, because something tells me that mic input plug-in power may damage the headphone output circuitry... but the malfunction occurred on its own.