Amplifier 18W

This is a class AB audio power

amplifier using the Hitachi HA13118

module. It is easy to construct and has a

minimum of external components. The module

has a high power output from a low voltage

supply using the bridge tied load method, and a

high gain of 55dB. This will be especially

useful in applications where the input signal is

a low level, without requiring the use of a

separate pre-amplifier, eg. a guitar practice

amplifier.

D.C. Input : 8 - 18V at 1 - 2 A

Power output :

18W maximum, 4 ohm load, - 18V DC supply

> 10W RMS 4 ohm load,- 18V DC supply

> 5W RMS 8 ohm load 18V DC supply

> 6W RMS 4 ohm load 12V DC supply

S/N ratio : > 70 dB

THD < 0.2% @ 1W

Freq. Response : ~ 30 Hz to 30 kHz, -3 dB

Input level : < 25 mV, for full output (G > 50dB)

Input Impedance ~ 30 k ohm