i’m not familiar with exactly the approach you are trying to take (are you following a paper?). You have some problems with the tuning. Firstly you want to send a signal to tapout~ in order to get a delay of a fractional number of samples. Secondly, i would recommend running the part of your patch that features a feedback loop inside a poly~ so that you can lower the signal vector size. Otherwise you will find that you can’t play high notes.
Here is a karplus strong patch which shows these things: