When troubleshooting audio reproduction equipment, what approximate RMS level should be expected at the input of the audio amplifier?

The expected RMS level at the input of an audio amplifier is typically around 1,000 millivolts, or 1 volt. This value reflects standard operating levels for consumer and professional audio equipment. Audio signals are usually balanced at this RMS level to ensure a good signal-to-noise ratio while minimizing distortion. This level is sufficient to drive the amplifier without clipping or other undesirable audio artifacts, ensuring high-quality sound reproduction.

The other values presented don’t align with typical audio amplifier input expectations. For instance, 500 millivolts might be too low for many amplifiers to function optimally, potentially leading to increased noise or lower overall volume. Similarly, 2,000 millivolts, or 2 volts, could be too high for some systems, risking distortion or damage if the amplifier is not designed to handle input signals of that magnitude. Lastly, 250 millivolts may be insufficient for clear audio performance and could also lead to an increase in noise or a decreased signal strength. Thus, 1,000 millivolts is the most appropriate and commonly accepted RMS level for audio amplifier inputs.