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Audio Filters Circuits
Audio Filters Circuits
Brick-wall lowpass audio filter needs no tuning
The filter should provide adjustable gain to maximize SNR at the audio processor's first stage. The filter's frequency response should also include a notch at 19 kHz to achieve maximum attenuation at the FM-subcarrier pilot-tone frequency and thus minimize phasing problems. To reduce manufacturing costs, the filter should require no in-process...
DPPs program key parameters of bandpass filter
The three-amplifier implementation of the state-variable filter in Figure 1 provides for second-order bandpass, highpass, and lowpass responses. The strength of the circuit, however, is in the bandpass response (VOUT/VIN), in which it`s easy to achieve high gain (G) and high Q. These two characteristics are important in applications in which...
Highpass filters use modified equal-element design
Using a modified equal-element design for a lumped-circuit lowpass filter has several advantages over the well-known equal-element design (Reference 1 and Reference 2). The modified design exhibits superior passband performance with only modest degradation of stopband selectivity. Moreover, the modified design is simple and easy to manufacture....
Cascade bandpass filters for higher Q
Switched-capacitor filters that are preset for a given bandwidth sometimes do not deliver the bandwidth or Q an application requires. By inverting the clock between two switched-capacitor bandpass filters, such as the MSFS1 from Mixed Signal Integration Corp, you can configure a high-Q filter (Figure 1). The MSFS1 is a selectable, seventh-order,...
This circuit is taken from the Progressive Communications Receiver in most of the recent ARRL Handbooks. Values for the 40 meter band are shown. If you want the ultimate in a bandpass filter for 40 or 20 meters, check out the bandpass filters in "An Integrated Contest-Grade CW Station", Solid State Design for the Radio Amateur, by Wes Hayward...
There are applications where a particular band, or spread, or frequencies need to be filtered from a wider range of mixed signals. Filter circuits can be designed to accomplish this task by combining the properties of low-pass and high-pass into a single filter. The result is called a band-pass filter. Creating a bandpass filter from a low-pass...
Closing the loop deepens notches
Notch filters remove a single unwanted frequency from an input signal. They are also a vital component of pulse-shaping networks, such as time-averaging filters. You can tune a state-variable filter over a wide range by changing the time constants of its integrating amplifiers (References 1, 2, and 3). Textbooks focus on its high-pass, bandpass,...
10 Band Graphic Equalizer
With graphic equalizer we make selective cutting off or boost, of selected departments of acoustic spectrum. With this way we can adapt the musical reproduction, in the characteristics of space where we hear. This can create however also problems if go to far specifically in the gain of some area, with result the distortion. The circuit should...
Adjustable high-frequency notch filter
Although you can obtain universal, resistor-programmable switched -capacitor filters that are configurable as notch filters, most cannot operate at bandwidths higher than 100 kHz. Further, the typically 16- to 20-pin packages do not include a continuous -time, antialiasing filter to prevent spurious signals from appearing at the output. By using...
Filter design uses image parameters
The technique applies to highpass filters. You derive a composite highpass filter by using m-derived terminating half-sections with one or more constant-k interior full sections. Classic image-parameter design used m-derived half-sections with m=0.6 for best passband impedance matching (in other words, high input and output return losses).
Low-Jitter Clock for High-Speed Data Converters
Figure 1 illustrates the simplified block diagram of a typical high-speed data converter system. The system consists of a bandpass filter, ADC, high-frequency clock, high-speed storage device, and post processing unit. Aside from the MAX104, the high-frequency clock plays a significant role in determining the accuracy of a high-speed data...
Amp with Tone Controls & Soft Switching
Built around an LM380, this amplifier includes tone controls and electronic "soft switching". The soft switching circuitry ensures power is built up gradually eliminating the dc thump. The soft switching is enabled by a BD131 transistor wired as a switch in emitter follower configuration. The collector is wired to a permanent supply voltage, the...
low pass filter subwoofer
The acoustic filters are met in various points in the sound systems. The knownest application they are the filters baxandal for regulating tone low and high frequencies and filters crossover where the acoustic region is separated in subareas, in order to it leads the corresponding loudspeakers. The application that to you we propose is a simple...
300HZ - 3KHZ Audio Filter
The human speech apprehend a small area of frequencies, that is extended from 300HZ until 3KHZ. This spectrum is also internationally recognized for the transmission of speech via telecommunications networks. This is also the mainer use of this circuit, one and it can be used in uses that we needed this concrete spectrum of frequencies,...
Surround Sound Decoder
The particular circuit does?t have the requirement to replace the trade decoders Surround, because this they have many more facilities and possibilities. It give however the possibility in many try with this article of decoding. The coding in Stereo Dolby Surround show the tendency to be abandoned and is replaced with digital DTS, Dolby 5.1...
Stereo sound balancer
It many times happens, we want erase or decrease in a musical song, the voice of singer or some other sound that usually is written in same level and in the two channels. If we remove between them two signals of channels, we can take in the output a mono signal without the voice. Here exist a problem. The sound of bass instrument is also this...
High-Pass 20HZ to 200HZ Filter
A simple circuit, High-Pass filter, variable between frequencies 20HZ until 200HZ, useful in a lot of cases elaboration of sound signals. The regulation is achieved with the double potesometer 47K? and the frequency response in his two extreme places, appears in the schematic.
Stereo Preamplifier and Bass-booster
This preamplifier was designed to cope with CD players, tuners, tape recorders etc., providing a gain of 4, in order to drive less sensitive power amplifiers. As modern Hi-Fi home equipment is frequently fitted with small loudspeaker cabinets, the bass frequency range is rather sacrificed. This circuit features also a bass-boost, in order to...
Low pass filter for Subwoofer Circuit
The application that to you we propose is a simple filter of region that limits the acoustic region (20-20000Hz) in the region 20-100Hz. With the manufacture that to you we propose you can make a active filter in order to you lead a loudspeaker of very low frequencies. With this you will place one bigger speaker between the HIFI speakers of you....
Two low voltage, low power zeners are used to control electronically the level of an audio signal. The attenuation range is from 6 to 58dB for an input current from 0.042 to 77 mA corresponding to a control voltage from 2.7 to 7.5V. If control voltage is limited to 5V, the attenuation is around 30dB at a control current of 2mA. This is not an...
Two low voltage, low power zeners are used to control electronically the level of an audio signal. The attenuation range is from 6 to 58dB for an input current from 0.042 to 77mA corresponding to a control voltage from 2.7 to 7.5V. If control voltage is limited to 5V, the attenuation is around 30dB at a control current of 2mA. This is not an...
Audio isolation transformer
If you want to build one yourself, you have to get two audio transformers which have 1:1 transformation ratio and greater than 1 kohm impedance. There are high quality audio transformers in the markes that meet those specs, but those can be quite expensive. Another option it to use 600:600 ohm isolation transformers widely available for...
Low pass filter for Subwoofers
In the form it appears the theoretical circuit of filter. In first glance we see three different circuits that are mainly manufactured round two operational amplifiers. This circuits constitute mixed, amplifier with variable aid and a variable filter. The manufacture end needs a circuit of catering with operational tendency of catering equal...
Two way Loudspeaker cross-over
The resistance of loudspeakers is characterized in a frequency depending on the destination and their press. Loudspeakers are distinguished, as for the destination, in loudspeakers of low frequencies, woofer intermediate, mid-range and high tweeter. Their resistance in W is 4W, 8W and 16W. Cross-over that we present it is intended for...
Opamp Filters schematics
The figures below illustrate using opamps as active 2nd order filters. Three 2nd order filters are shown, low pass, high pass, and bandpass. Each of these filters will attenuate frequencies outside their passband at a rate of 12dB per octave or 1/4 the voltage amplitude for each octave of frequency increase or decrease outside the passband.
Feedback Band-Pass Filter
One application of this handy circuit is a graphic equalizer, created by feeding a signal to a number of parallel band-pass filters each tuned to a different frequency; typically octaves apart. Then, you can adjust the strength in each band via a front panel potentiometer. The outputs of all the filters are then summed to create overall...
The Ultimate Audio Filter
This project is an extension of two projects - first is the work on adding an APF-type high-Q bandpass feature to the 2nd RX of the FT-2000. More on that project may be found by CLICKING HERE. And the second driver is the memory of the fun I had as a kid with active filters. An active audio filter is in many ways comparable to the digital variety
Subwoofer Filter Circuit Using Op Amp Tl072 Audio Circuits
The Subwoofer Filter Circuit Allows The Addition Of Subwoofers To An
Subwoofer Filter circuit and explnation
Here is the ambit diagram of an opamp based subwoofer filter. Audio frequencies beneath 200Hz are advised to be in the subwoofer range. So a subwoofer clarify will be about a low canyon clarify with a cut off abundance of 200Hz. The alive of this beeline advanced ambit is as follows. The larboard approach of the audio antecedent is affiliated to th
Low Pass Filter circuit
AUDIO AMP + 3KHz FILTER
AUDIO AMP + 3KHz FILTER. This circuit is the audio amp section for a complete optical transmitter. The increased circuit and filters the voice audio signals from an electret microphone
Audio Amplifier Circuits
Audio Oscillator Circuits
Audio Mixer Circuits
Audio Equalizer Circuits
Audio Tone Balance Circuits
Beeper Buzzer Circuits
Vacuum-Tube Valves Circuits
Musical & Effects Circuits
Ultrasonic distance finder circuit
The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is measured. There are three main categories of distance measurement methods in use: a) By...
Simple Metal detector circuit with CD4030
Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to find something potentially valuable, hidden a few centimeters below the soil. So many...
Fully automatic watering circuit for flower pots
Many times for various reasons we forget or can not water the plants that we have in our homes. And many humidity sensors units just notify us with a beeping sound or with a flashing light, that the pot needs watering. But what if we are away from home? This circuit comes as a solution to this problem. Depending on humidity of the pot at...
Simple deep searching metal detector circuit
The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the circuit of this metal detector, it is possible to detect a metal coin in depth of 90 to...
Sub-Harmonic Bass Converter for Electric Guitars
The sub-harmonic bass generator is a sound producing unit for guitars. The sound it produces looks very much like that of the bass guitar. The octave generator is sometimes quite unusual since it does not produce any of the usual ways of coloring the sound, such as filtering or distortion. Instead, a frequency division system produces outputs...
Echo Depth Sounding Sonar for Boats
In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the calibration of the rope. This arrangement still exists in some yachts. The big...
100W HiFi Audio Amplifier Circuit
This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power supply must be symmetrical so that no electrolytic capacitors are needed at the outlet....
Plant-Pot Water Level Indicator Circuit
A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower. The circuit of the device is shown in Figure 2. The water detection is made from the bottom...
Analogue Sound Preasure dB-Meter Circuit
The best human ear can capture sounds from 20Hz to 20KHz. These limits are known to be the broadest that can exist. Normally the normal limits range from 100Hz to about 13KHz and depend on the age and health of the individual. We for our measurements and to have a good accuracy we will get the limits of 20Hz to 20KHz. A sound to be heard does...
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