Designing Lowpass and Highpass Filters Butterworth R1 Input 2.294 K C1 150 nF 1.059 K C2 150 nF 476.5 R C3 150 nF R2 R3 + _ A1 NE5532P Out R4 1.2 K R5 1K 207 (a) Bessel R1 Input 3.050 K C1 100 nF 902.7 R C2 100 nF 519.9 R C3 100 nF R2 R3 + _ A1 NE5532P Out R4 1.2 K R5 1K