Balanced Output Stage With Bridged Feedback
In balanced signal transmission, two identical signals are transmitted simultaneously with inverted phase and combined at the receiving end, thereby canceling out common-mode noise and interference. This assures pure high-quality signal transmission. The principle of balanced sound transmission is shown in Figure 4. The outputs of the two amplifiers AMP1 and AMP2 are connected to form a cross-feedback loop, which sends the symmetrical (+) and (-) signals with low impedance to the next stage. The signals are isolated from the ground line, resulting in an ideal balanced circuit. Even if one side of the output is grounded, both amplifiers continue to operate, and the output voltage does not change.