Dynaco Stereo 120


I was looking through the for sale pages of a website and came across the images of the insides of a Dynaco Stereo 120
https://img.usaudiomart.com/uploads/2020/09/15/user_148995_large_b4f2d47a507010bc64bd6919d7fe4309.jpg

It was evident that a winding around the capacitor was done, does anyone know why?
Is it an electromagnet that has been wound, or simply to introduce inductance, is this an old lost technique?

I am curious, and figured someone in Agon might know?
128x128rixthetrick
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@n2tubes Just came across this post and checked out your website. It's wonderful to see you carry on a family business and bring these amps back to life. I have other manufacturer's vintage tube electronics in my systems and they are superb.