— When I bought my Walkman I needed to listen to it not only using batteries but in stationary conditions. But there wasn't any jack socket that I could use to plug it in. And what there was wasn't suitable for the electrical system. So I was necessary to make something instead of putting in these small batteries every time, something made from two bits of wood. Instead of the small batteries it was pushed into the battery section and was connected directly to the transformer, it was connected here to this transformer like. In principle these jack sockets for this exist. Naturally, you need to look for plus-minus. This was made, probably, about two years ago. About 98. I don't really feel like wasting money on buying a special adaptor with this kind of jack socket.