Image on left is from 4 days ago, but the pimple was slowly forming over around 2 weeks.

The goop was sticky, not oily. Earphones are Panasonic RP-TCM130.

I was not able to find an explanation.
Something to increase cable lifespan, lubrication, rubber disintegrating, sweat and earwax that somehow got into the cable, dielectric grease, SCP-1407, no clear answer.

At first I thought the wires just somehow twisted. Nope.

  • @UsernameHere
    51•6 months ago

    High resistance in a wire inside the sheath would generate more heat at that point, causing the plastic sheath to melt/bubble. So if the wire inside the sheath got damaged, pinched or some of the strands of wire were broken.

    • @[email protected]English
      37•6 months ago

      These are earbuds, not big ass speakers. There shouldn’t be enough power going through those cables to do melt anything.

      • OrbituaryEnglish
        14•6 months ago

        You would be incorrect. If the power source shorts, it would heat the wires sufficiently.

        • @[email protected]English
          12•6 months ago

          And how much power do you think the DAC in a phone is going to output?

          The built in DAC in a phone can barely drive my headphones, let alone melt a silicone cable. They typically output less than a watt. On a good day. Rubbers melting point is 365c and 1 watt isn’t gonna do that.

          • u/lukmly013 💾 (lemmy.sdf.org)OPEnglish
            9•6 months ago

            They typically output less than a watt.

            Sounds optimistic. Checking a few USB to 3.5mm dongles, they seem to be around 25mW max at 32Ohms. Not sure how much that would change with short circuit, but I guess not much more.

          • @UsernameHere
            0•6 months ago

            Have you verified the specs on OPs headphones?

            Maybe I missed it but I don’t see where OP said this happened while connected to a phone.

            • @[email protected]English
              9•6 months ago

              They’re earbuds. You’re going to using them with a phone, maybe a laptop, or even in a pinch maybe a desktop. None of those output enough power to melt through a rubber cable without severely destroying themselves and never working again. OP would be posting “my phone exploded and I’m deaf now” not about the cable having a pimple.

              Even my dedicated amp, a Shiit Magni outputs 6 watts with both channels combined, and ain’t nobody connecting shitty earbuds to an amp. The rest of the cable is going to sink away the heat from 6 watts before the rubber could get hot enough to melt.