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100 microfarad electrolytic capacitor (C4)

LM386N-1 amplifier IC1

Of the many versions of the LM386 amplifier, we chose the LM386N-1

because it is designed to work with the supply voltage of 6 volts

required by this circuit.

Battery pack for 4 AA batteries

Edmund Scientific’s (www.edsci.com) 24"-diameter parabolic reflec-

tor, part #3053876

SPST toggle switch, used as the on/off switch

830-pin breadboard

Five 2-pin terminal blocks

Knobs for the potentiometer

Two phono jacks

Two right-angle phone plugs

We use right-angle plugs to avoid having a loop of wire coming out of the

box. (You can also use something called a banana plug and jack.)

Headphones

We used a set of Philips HP170, but you can use any headphone you

have available. Obviously, the better quality headphone you use, the

better the sound quality.

Headphone jack

We used a^1 ⁄ 4 " jack. If your headphone plug is a different size, use the

appropriate size jack or get an adaptor.

Enclosure to protect the circuit

We used a plastic box, RadioShack part #2701807.

An assortment of different lengths of prestripped, short 22 AWG wire

PVC adaptor with^3 ⁄ 4 " female slip fitting on one end and a 1" thread fit-

ting on the other end

PVC 90° joint with a 1" slip fitting on both ends (one male and one

female)

PVC adaptor 1" female slip fitting to a 1" female thread

PVC 1" end cap with a 1" female slip fitting

^5 ⁄ 16 "-diameter wooden dowel

120 Part II: Sounding Off!