The ideat of a integrated amplifier has some basic advantages. The deciding one is the short signal way, because all electronic components are summarised into a case. In the CA 270 this idea is strictly realised. From the begininng HOLBORNE used tubes and semiconductors in a special mix to build amplifiers with ultrashort signal way. There are no components which have only advantages or only disadvantages . The challenge as is to find for every function in an amplifier design the optimum component. Thus electron tubes are used as well as field effect transistors, bipolar, Mosfets and of course tubes. Tubes also have even today qualities which they make for certain applications absolutely unrivaled. Besides, the principal purpose has always remained the same: To build amplifier they do not generate a sound, the famous amplifying wire so to say. The reproduction for their part should occur so musically as possible. Musically means that the heard is free from all relevant disturbances which disturb the absorption by the listeners. There is not the perfect amplifier. The building of an amplifier is in this sense the most careful counterbalancing and reducing of rest mistakes.