Hi Jean!!
Ahh. J2/HDR16. Thats where all the magic is! Those are all of the outputs of the discrete wave forms that make up the benjolin. You can use these to patch into other gear as control signals or audio signals or patch them into the VCO&VCF CV inputs. This is the key to unleashing the monster.
(I'm finally working with rob on a new upgraded bejolin PCB and kit. This one includes an echo! I'm hoping to have it done and in my store by this summer. Wish me luck!)