The overall output of an AM/CW/SSB receiver can be adjusted by means of manual controls on the receiver or by use of a circuit known as:

Receivers use Automatic Gain Control (AGC) to keep the audio output volume relatively constant despite variations in the received signal strength. AGC achieves this by automatically adjusting the gain of the RF and/or IF stages based on the incoming signal level. Automatic Load Control (ALC) is a common distractor, but it is used in transmitters to prevent overdriving the final amplifier. Automatic Frequency Control (AFC) keeps a receiver tuned to the correct frequency, which does not adjust the overall output amplitude.