Pazzy

In communications receivers and microphone amplifiers for transmitting equipment, there is frequently a need for a narrow, low-frequency band-pass filter that lets only the voice band through. This band is usually defined to be the portion of the audio frequency spectrum between approximately 300 Hz and 3300 Hz. In order to implement such a filter, we have calculated the values for two fifth-order Butterworth filters having these corner frequencies and connected them in series. The result is a band-pass filter for the desired pass-band with a skirt steepness of 100 dB/decade.  The first opamp (IC1) acts as a buffer. Speech Filter Image :   The circuit can be powered by a unipolar supply voltage between 5 V and 18 V, which is a broad enough range that it should always be possible to find a suitable voltage when building the filter into existing equipment. The current consumption of the filter is only a few milliampères, which should rarely pose a problem. There is fairly wide...

Description. Many low pass filter circuits for subwoofer are given here and this is just another one. The circuit given here is based on the opamp TL062 from ST Micro electronics. TL062 is a dual high input impedance J-FET opamp which has very low power consumption and high slew rate. The opamp has excellent audio characteristics and is very suitable for this circuit. Out of the two opamps inside TLC062, first one is wired as the mixer cum pre amplifier stage. The left and right channel are connected to the inverting input of IC1a for mixing. The gain of first stage can be adjusted using POT R3.The output of the first stage is connected to the input of second stage through the filter network comprising of components R5,R6,R7,R8,C4 and C5. The second opamp (IC1b) serves as a buffer and the filtered output is available at the pin 7 of the TLC062.   Circuit diagram.   Power supply for the circuit. Notes. Assemble the circuit on a good quality PCB. The circuit can be powered from...

This circuit passes frequencies in the 300Hz - 3.1kHz range, as present in human speech. The circuit consists of cascaded high-pass and low-pass filters, which together form a complete band-pass filter. One half of a TL072 dual op amp (IC1a) together with two capacitors and two resistors make up a second-order Sallen-Key high-pass filter. With the values shown, the cut-off frequency (3dB point) is around 300Hz. As the op amp is powered from a single supply rail, two 10kO resistors and a 10µF decoupling capacitor are used to bias the input (pin 5) to one-half supply rail voltage. Circuit diagram:  Voice Bandwidth Filter Circuit Diagram The output of IC1a is fed into the second half of the op amp (IC1b), also configured as a Sallen-Key filter. However, this time a low-pass function is performed, with a cut-off frequency of about 3.1kHz. The filter component values were chosen for Butterworth response characteristics, providing maximum pass-band flatness. Overall voltage gain in the p...

This is the simplest Sub woofer Low Pass filter Circuit using uA741 single op amp ic . The circuit is very low cost with respect to their work. The cut off frequency of this circuit is 25Hz to 80Hz maximum. Using this circuit , you can easily design a 2.1 Sub-woofer Speaker System at your own Home. The circuit contains very few components.In Pakistan, the cost of this circuit with PCB is Rs:45 The same circuit is working in my own hand made sub-woofer system. So Try this [ ] Parts List:   R1,R3,R4 = 10K 1/4W R2=100K 1/4W CY1,CY2 = 0.22uF Polyester C1,C2 = 10uF/25V Electrolytic IC1 = uA741A Single Op-Amp Ic + 8 Pin Ic Socket 3 Pin Male & Female Connector x 2 2 Pin Male & Female Connector x 1 PCB as in required size 4.5 cm x 3.4 cm

Tone control circuit is used to adjust the tones before entering the amplifier. Tone control over equipped with a loudness and filter directly without using the switch to disconnected or connected. Part of his filter that is C1 and R1 from ground to input , and for his loudness on the R4 and C3 are connected to the input and then go to VR1. C2 and R3 go from ground to the input . After the input is set by volume or VR1 then procesed again by treebel ie C8 , R13 , R14 , and VR2 . Bass on R10 , R11, R12 , C7 ,C8 , and VR3. For supply voltages has been given a stabilization in Q3. See schematic below : Click to view larger Part list : R1 = 100K R2 = 50K trim R3 = 22K R4 = 15K R5 = 1K R6 = 4K7 R7 = 330K R8 = 330K R9 = 3K3 R10= 5K6 R11= 8K2 R12= 5K6 R13= 1K R14= 1K R15= 50K TRIM R16= 50K TRIM R17= 330K R18= 4K7 R19= 47K R20= 1K R21= 4K7 R22= 2K2 R23= 100R R24= 22K C1 = 15n C2 = 15n C3 = 560p C4 = 4u7 C5 = 33u C6 = 4n7 C7 = 39n C8 = 39n C9 = 4u7 C10=4u7 C11=470u C12=100u Q1 = C1815 Q2 = C828...