Please see the chat and amplifier that you quoted on. The understanding is that you complete the rask for a fixed price although you asked that a hour rate project is to be made. We both agree that when the design is done that the fee of 450 is to be paid for the task, irrespective of the time spent to complete the task. My engineer will review the schematics and consult if he sees any possible problem on the design. Then you can complete the pcb. Please take care of the component that is to ne used as not to become obsolete.