Price - Stock No 415
This low cost amplifier provides modest amplification from a headphone jack.
- Check the P.C.Board for damage to
tracks. Any breaks can be soldered over. Check with a multimeter
or electronic circuit tester.
- Identify the three resistors, see Resistors.
- Insert the resistors and solder in place - see Soldering
- Insert the IC socket taking care to orientate the
locating dot. Solder in place.
- The 6 PCB pins can be inserted and soldered.
- Identify the two greencap capacitors, locate their positions and solder, see Capacitors.
- Care needs to be taken ensure the electrolytic capacitors are inserted with the correct
polarity. Note the values and polarity of the capacitors and solder in place.
- The switch can now be soldered to it's PCB pins.
- The battery holder is inserted from the copper side of the pcb and needs to be stood off the board to allow access for the soldering iron. Care should be taken to ensure excess solder does not short circuit the PCB - solder in place.
- Cut the figure 8 wire into two suitable lengths. The ends
of the wire needs to be stripped to bare the copper wire.
- Tin the bare ends of the wire - refer Tinning
- Attach the speaker with one length of fig. 8 wire - note the polarity.
- Attach the headphone jack with the other length of fig. 8 wire. The tip of the jack is positive.
- Adjust the legs of the LM386 to match the socket
- Insert the IC with the locating dot as shown in the
Operation and Testing
- Insert a 9V battery.
- Connect an audio source to the input jack and turn the switch on.
- Use the volume control on the audio source to adjust the output volume.
View the Datasheet for the LM386.
Troubleshooting, if necessary will involve careful
checking of locations and polarity of components, in particular the LM386, 1he 100uF and 470uF capacitors. Re-solder all joints and check to make
sure you have not bridged across between
any two adjacent component legs. The end of a
broken hacksaw blade sharpened on an emery
wheel is a good tool for cleaning between soldered joints.
Contact CdS electronics