Thank you for the response. In regard to the Nokta Makro waterproof Headphones, I never noticed any crackling. They worked fine the last time I was able to use them and then the next time I went to use them, they no longer worked. After that, I hunted on land with Sony wired headphones using the adaptor and they worked great with loud clear audio. I then purchased a pair of Gray Ghosts while I wait to hear back from Nokta Makro about fixing the Nokta headphones and when I went to use those, I'm only getting audio out of one ear.
I was thinking if there was an issue with the machine, the Sony headphones wouldn't have worked with the adaptor or I would have issues charging the machine.