Beginner Struggling

Hi, I am new to TW, I have been attempting to build the Strangeaparatus version,  the modular construction appealed to me. I naively thought this was a proven circuit. Has anyone built this to a working standard ? My theory understanding is limited, but the oscillators/ mixer is difficult to work and is unstable. The linear loading on the pitch antenna is way out.
Now reached the point of abandoning this, is there a better pitch/vol circuit available for a newby.
Regards oilzum