2  LM741 Op-amp 8-pin DIP IC
2  Zener Diodes
3  10 k resistor
1  1 k resistor
1  ? k resistor
1  ? k resistor
3  0.1 uF ceramic disc capacitor
1  10 uF electrolytic capacitor

1  solderless breadboard
x  wires to use on breadboard (solid copper, prefer tinned)
1  wire cutting/stripping tool
1  function generator (sine, var freq)
1  +/- 12 VDC power supply (variable preferred)
1  signal cable, source to breadboard
1  oscilloscope
2  10M/1Mohm impedance oscilloscope probes