Amplifier circuit diagram

Amplifier working process and composition principle:

(1)Work flow

Input - preamplifier stage - push stage - OTL power output stage - speaker

(2) Composition principle

①Preamplifier stage (input stage)

The preamplifier stage is a common-emitter amplifier circuit connected by V1 tube, R1, RW2, R2, R3, R4, R5, C1, C2, C3, C4, etc. It adopts a voltage-division current negative feedback bias stabilization circuit.

②Push level

The push stage consists of V2 tube, R6, RW4, R7, R8, R9, V7 tube, V8 tube, RW3, R10, C5, C6, C7, which are connected to form a common emitter voltage divider bias stabilization circuit. It undertakes the task of providing sufficient push current to the power output stage. The push stage power output stage adopts direct coupling method.

③OTL power output stage

The output stage has the task of outputting signal power to the load. It consists of an NPN composite tube composed of V3 and V4 tubes. The PNP composite tube composed of V5 and V6 tubes is quasi-complementary symmetrical with R11, R12, R13, R14, and C8. circuit.

3. Practice making loudspeaker printed circuit board drawings and electrical component layout drawings

4. Practice the component parameters and models of loudspeakers