Description
Here is the schematic for an 8 watt audio power amplifier. This amp can be used as a simple booster, the heart of a more complicated amplifier or used as a guitar amp. It is very small and portable unit and can be powered through 12V battery. I built the circuit on a Vero Board and had to add extra inductors, capacitors and resistors to prevent oscillation.
Circuit diagram:
Parts:
- R1 = 47K
- R2 = 2.2R/1W
- R3 = 220R/1W
- R4 = 2.2R/1W
- C1 = 100nF-63V
- C2 = 10uF-25V
- C3 = 470uF-25V
- C4 = 2000uF-25V
- C5 = 100nF-63V
- IC1 = LM383
- SPKR = 4ohm/8W
Notes:
- IC1 must be installed on a heat sink.
- C1 is for filtering and to prevent oscillation and should not be omitted.
- The circuit can be built on a Vero Board, universal solder board or PC board, the PC board is preferred.
- The circuit draws about 880Ma at 12 V.
- By swapping the values of R2 and R3; you can turn this amplifier into a guitar amp with no preamp required.
- If you can't find 2000uF, then replace C4 with a 2200uF unit.
- If you add a 0.2uF capacitor in series with a 1 ohm resistor to the output you can prevent oscillation of the circuit under certain conditions.
circuit from http://www.extremecircuits.net/2009/12/8-watt-audio-power-amplifier-schematic.html