Next step is not a business plan. Get an NDA (non-disclosure agreement).
Find professionals willing to listen to your idea ... after the NDA is signed, of course.
Determine if you have a valid concept ...
I have an idea for an audio product what should I do?
Without giving too much away it involves working with smaller digital amplifiers that are modified for a certain application. Should I contact an electrical engineer or someone in the business already who builds audio amplifier products or...?? I have zero experience myself with building any audio related products but I think the idea I have is intriguing. Thanks for any help!