mini stereo amplifier

EE 28 July/August 1986 Thisminiamplifierisbasedonthe ThomsonTypeTEA2025.Inthis 16-pin DIL device hides a stereo amplifier that with a supply voltage of 9 V will provide 1 watt output per channel into a 4-ohm loudspeaker. At full output, the input sensitivity is about25mVpp.Ifthisistoosensitive, a resistor R m ay be connected between pin 6 and C7and between pin 11 and C2. The sensitivity then becomes(25+1/2R)mV,provided R>1kg.Furthermore,thesupply voltage may lie between 3 V and 12 V. The operation of the IC cannot be discussed here, but for those interested its internal circuit diagram is reproduced in Fig. 1. One useful feature of the TEA2025 is that it has a soft-start circuit on board, thus obviating annoying plops in the loud- speaker at switch-on. mini stereo amplifier 1 Construction of the amplifier is fairly sim ple, but has its peculiarities. First, there is the earth, which in this case should not be of wire, but rather con- sist of a m etal earth plane (if you designyour...