Why is the frequency response at the input of the second output stage of a distribution amplifier sloped?

The frequency response at the input of the second output stage of a distribution amplifier is sloped primarily to reduce intermodulation distortion levels caused by high amplitude input signals. In a distribution amplifier, particularly one that handles a wide range of frequencies and signal amplitudes, high amplitude signals can interact in non-linear ways. This interaction can produce unwanted harmonics and intermodulation products, which degrade the quality of the signal being distributed.

By implementing a sloped frequency response in the second output stage, the amplifier can effectively limit or attenuate certain frequencies that are more likely to cause this distortion when they are at high amplitudes. The careful design of the frequency response ensures that the system maintains signal integrity for both low and high amplitude inputs while minimizing distortion. This allows for clearer transmission of the signal across the distribution system, ultimately enhancing performance and listener experience.

In contrast, options focusing on amplification of low signals or achieving a flat output response do not address the root cause of distortion management. Improving overall signal clarity is a goal, but the specific design decision to slope the frequency response is fundamentally tied to distortion reduction.