This is an a simple Tone Control Circuit using TDA1524A. Is the heart pillar in the work that is IC chip diagram of Philip. You can use a tone control or a portion of the lower portion of fines sound, treble and balance to get all setly can be extended by a given signal power can reach up to 3 Vrms with 20 dB and rates expansion are guilty are crazy just over 0.014% with a frequency of 1 kHz and important. The circuit is not difficult to build a team and soon, then old suit of education or be used indoors or outdoors can apply the work should be done.
Duty cycle starts from the input power supply built into the pin 3 is the positive voltage and negative voltage to pin 8, this circuit will only Class C and R of the devices to filter out frequencies in different areas. Some may work then. When the signal from the sound source to pin 15 of IC1, the input signal is coupled through C1 and C2 signals from each channel.Left and right, then the IC signals are amplified with the C6 and C4 for controlling the frequency of the sound from the Department that the switch S1 is the option of using the tone control a region or sector will adjust the bass Cape C5 and C3 act as control VR1-VR4 frequency to adjust the volume, balance, treble and bass, respectively.
Then the signal was expanded and adjust the frequency, and sends the pin 8 and pin 11 of audio IC of each box R1 and R2 will serve to diminish the right signal And the signal coupling through C9 and C10, with R3 and R4 removing DC comes from the earth to the C11 and C12 will be to remove high frequencies from 70 kHz up. A land, and then sends the signal to the output signal and a voice came out clear.