Simulação e construção de um pré-amplificador valvulado e um transistorizado

Abstract

Since its inception, tube amplifiers always delighted their users through its fantastic characteristic tone, but some years late, occurred the introduction of the transistor, a more accessible device that invaded the production lines of amplifiers factories around the world. The negative point of the tube amplifiers lies in their high commercial value, which becomes inaccessible to the general public. Initially it was necessary to identify two similar circuits where their amplifier element (tube or transistor) were different. Simulations of the tube's and transistor's pre-amplifiers were performed in order to know all the stages of circuit operation and their characteristics. After that, the transistor circuit layout was developed, the tube circuit was assembled point to point. After the prototypes construction of both preamplifiers, tests were performed in the laboratory. No major problems were encountered during the work performed, the prototypes showed the expected characteristics according to the simulations results.