Hey everyone. I am gonna start building my first amp soon and would like some suggestions for a diy preamp. This is the power amp section i am getting, http://www.vellemanusa.com/products/view/?country=us&lang=enu&id=521723. I want to run everything off a 9v dc power supply. I would also like to have a three knob tone control and either a separate gain channel or gain settings in the preamp. Thank you.