Question 1 (45 marks) As an audio engineer, you are asked to design an amplifier circuit to remove an unwanted hum at 60 Hz. The circuit needs to have a magnitude response with: a roll off of at least 60 dB/decade; a passband gain of 10 dB; an upper cutoff frequency of 80 Hz; and a stopband of 40 Hz. You can use any number of amplifiers, resistors, capacitors and inductors. (a) Design your circuit using the Butterworth filter design, clearly labelling all component values. You need to use 1k22 resistors in the low pass filter and 5 nF capacitors in the high pass filter. (20 marks) (b) Now redesign your circuit using the cascaded prototype filter design, clearly labelling all component values. You need to use 5nF capacitors in your circuit. (20 marks) (c) Using a sketch of superpositioned magnitude response plots of circuits (a) and (b) above, compare and discuss the differences between both designs. (Note: You do not need to use semi-log paper for this sketch) (5 marks) Question 1 (45 marks) As an audio engineer, you are asked to design an amplifier circuit to remove an unwanted hum at 60 Hz. The circuit needs to have a magnitude response with: a roll off of at least 60 dB/decade; a passband gain of 10 dB; an upper cutoff frequency of 80 Hz; and a stopband of 40 Hz. You can use any number of amplifiers, resistors, capacitors and inductors. (a) Design your circuit using the Butterworth filter design, clearly labelling all component values. You need to use 1k22 resistors in the low pass filter and 5 nF capacitors in the high pass filter. (20 marks) (b) Now redesign your circuit using the cascaded prototype filter design, clearly labelling all component values. You need to use 5nF capacitors in your circuit. (20 marks) (c) Using a sketch of superpositioned magnitude response plots of circuits (a) and (b) above, compare and discuss the differences between both designs. (Note: You do not need to use semi-log paper for this sketch)