Eight 100 ohm resistors (R15–R18, R32–R35)
Two 10 kohm potentiometers (R7, R24)
Four 47 kohm resistors (R3, R4, R20, R21)
Two 100 kohm resistors (R5, R22)
Two 2 kohm resistors (R2, R19)
Two 5 kohm resistors (R6, R23)
Two 1 kohm resistors (R9, R26)
Two 220 kohm resistors (R10, R27)
0.001 microfarad ceramic capacitor (C3)
Two 0.1 microfarad ceramic capacitors (C1, C4)
Two 10 microfarad electrolytic capacitors (C2, C5)
Eight green size T-1^3 ⁄ 4 LEDs (LED1–LED8)
Eight red or orange size T-1^3 ⁄ 4 LEDs (LED9–LED16)
Two LM358 op amps (IC1 and IC2)
Electret microphone
We use the Horn part #EM9745-38 electret microphone for two reasons:
high sensitivity and a reasonable size that makes it easy to handle. You
can use other electret microphones; see Chapter 3 for the criteria to
help you choose one.Two 830-contact breadboards
One 4 AA battery pack with snap connector
Eleven 2-pin terminal blocks
Two knobs (for the potentiometer)
Eight 2N3904 transistors (Q1–Q8)
A wooden box
We found one at a local craft supply store that was just the right size to
hold the electronics for this project.An assortment of different lengths of prestripped, short 22 AWG wire
Several feet of black 20 AWG wire
Several feet of red 20 AWG wire
Chapter 5: Making Light Dance to the Music 93