Figure 4.8. One side of the input is grounded. The other side goes to the negative end of a capacitor labeled C 1, 20 microfarad. The other end goes to the base of an NPN transistor. A resistor labeled R 1, 22 k ohms goes from the base to plus 12 volts. Another resistor labeled R 2 6.8 k ohms goes from the base to ground. The emitter goes through a resistor labeled R4, R e, 1.8 k ohms, to ground. The emitter also goes through a capacitor labeled C 2, 50 microfarads, to ground. The positive end of the cap goes to the emitter. The collector goes through a resistor labeled R3, R c, 4.7 k ohms, to plus 12 volts. The collector also goes to the positive end of a capacitor labeled C3, 20 microfarads. The negative end of this cap goes to the high output terminal. The other output terminal is grounded. There is a resistor connected between the two output terminals which is labeled R5, R l, no value is given. End verbal description.