An op amp. @Bordodynov's circuit is nearly as complex as a basic op amp.
The reason op amps work so well is that they use very high gain and a high ratio of feedback to control the amplification. You CANNOT do this with one transistor.
Bob
The reason op amps work so well is that they use very high gain and a high ratio of feedback to control the amplification. You CANNOT do this with one transistor.
Bob