Audio Kits
Digital Volume Control circuit schematic
The heart of this digital volume controller DVC circuit is IC2 4067, 16-channel analog multiplexer.
Because the 1kΩ has been connected between every input and output, the multiplexer can act like a potentiometer. The total resistance is 15kΩ . You can use different values for the resistor to obtain a different characteristic. The current consumption is [...]
Stereo noise blanker, suppressor, limiter
This stereo noise blanker or suppressor attenuate the noise with 45dB when the music signal is low or null, is just a noise limiter. The noise blanker sensitivity can be adjusted with P1: the highest it gets the faster the noise suppression occurs. It has only one IC - 741 and 3 cheap transistors.
The maximum [...]
Automatic Gain Control - AGC
Automatic Gain Control or AGC is a circuit design which maintain the same level of amplification for sound or radio frequency. If the signal is too low the AGC circuit will increase ( amplify ) the level and if is to high will lower it to maintain a constant level as possible.
The Automatic Gain Control [...]
