I have a knob that needs replaced. I know a guy who for free will replace the knob (the middle knob on the first channel.) for free if i buy the know. That guy is my dad. He is a master of the sodering iron and has been in the electronics industry for years. You can ask him any kind of hardware question and he can answer correctly. Should I have him do it or take the head to the most trusted repair shop and spend 100 dollars on repairs. I have almost no money, but if you don't think he can help, please tell me. Thanks a ton!