Add to ORKGThe thesis describes different between any signal and audio signal from the used amplifier´s quality point of view. There are mentioned ways of origin of distortions and their effect on the audio signal quality. There is also described in detail the principal of operational amplifier, it´s circuit realization and ways to improve the circuit topology in order to reach the best qualities. Choice of parts used for discreet realization of operational amplifier is consulted. Last but not least the thesis contents the practical part, stating the reasons for realization of operational amplifiers from discreet parts and also describing two most commonly used topologies of operational amplifiers. Their discreet version is designed and there are comp...