DIY cassette tape delay / echo (stereo)

Here is my Time Machine. An homemade stereo cassette tape echo It took me 5 month to build. I had to start electronic from the very begining, and I think I’ve made every possible mistake before making this thing working. EDIT : Thanks everyone for your very encouraging comments, I really appreciate it ! A lot of you guys ask if I sell it or plan to build new machines. Answer is no, sorry. Portable Marantz are getting rare and expansive, and often need to be serviced. And I’m not an expert for that. It would cost you a lot of money for an old machine that would fails who knows when. Anyway, this guy here seems to work very well and is selling cassette echoes. For those asking for tutorial or schematics : I won’t make a step by step tutorial, but I can give you pointers. I invented nothing, I just modified a very old diy project and tried to make it stick to my needs. - This project is called Echo Matic. You’ll find everythi