Complementary NPN/PNP Audio Amplifier Circuit – Direct Coupling for Moderate Power
In this push‑pull configuration, Q3 is an NPN transistor while Q4 is its complementary PNP counterpart. The complementary pairing delivers a balanced, low‑distortion output, making the stage well suited for moderate‑power audio applications.
The design is fully directly coupled, which simplifies biasing and eliminates the need for additional coupling capacitors. This results in a cleaner signal path and improved dynamic response.
For a detailed explanation, see the “Directly Coupled Complementary‑Pair” section in Chapter 4.

Direct coupled complementary symmetry 3 w audio amplifier
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