My suggestion, and what's worked well for me, dig into DIY. I suggest starting with Nelson Pass. He makes things very understandable and his designs are easy to build. Mr. Carlson's Lab on YouTube is excellent material too. The scope of his channel goes way beyond audio, but he's very good at explaining things and he's started a Patreon where he's teaching electronics starting with the bareknuckle basics. Burning Amp lectures are good stuff too.