TAP is _already_ the WAV converted to trigger pulses. Converting them back to WAV would do no good. What you need to do i convert TAP data to binary data and then read that data into memory. Problem is that most games and software on tape consist of multiple files that use custom loaders that expect named pulses, to take them and unpack them as binary data into memory.
To be able to easily copy games and software from one tape to another, people in the early 1980's started ripping and repacking binary data into single file loadable format known as Turbo Tape. Popular formats used were, for example,Turbo64, Mr Z Turbo and so on. This is by the way what ignited the Cracking Scene, and made the C64 the most popular micro computer ever, and very much the reason why we still use it today. And this is why you don't want to load TAPes from your MMC64, because somebody already put a lot of work into making that long tape short and binary loadable.
