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Voltage-Controlled Attenuator (Volume Control) Using FET
Using the circuit shown in the schematic diagram below, we can control the low-level audio signals with ±3V variable DC voltage. This attenuator circuit uses a field effect transistor (FET) to shunt...
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60-dB Range Compressor For Audio
A compressor circuit shown in the schematic diagram below can produce consistent output of 1.4V P-P over entire 60dB range that is very useful for audio level/volume stabilization. As the main...
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Telephone Circuit: Music On Hold
Waiting a call hold can be boring if there is only silence on the line. It’s a good thing to present an “easy music” in call hold, make a long waiting time feels much shorter. This simple circuit...
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Loud 10-W Car Alarm Siren
By generating square-wave output that sweeps down and up in frequency, this circuit can produce force field of high-intensity sound inside car. This circuit can make a car thieve panics and decide to...
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Binaural Synthesizer/Mono to Stereo Converter for Small Speaker/Phones
This simple circuit can be used to drive two high-impedance loudspeakers or stereo phones, taking monophonic input (one channel), to produce a stereo signal which spread along the midway between...
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Tremolo Effect Circuit for Electric Guitar or Other Musical Instruments
Tremolo circuit is a kind of sound effect. We can see this type of effect is applied in guitar effect pedals. Tremolo effect is produced if we modulate the amplitude of an audio signal. The shape of...
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PC (Audio) Signal Generator Using RS232 Port
Using an RS232 port, we can generate square wave oscillation when transmitting data, and this can be “misused” as signal generator (square wave generator). This is a PC Signal generator produce a...
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Digitally Controlled Gate for Audio Signals
This circuit is equal to digitally controlled analog switch, but it uses transistor instead of integrated circuit. This circuit can be used for frequency range of audio signal 20-20kHz . The output...
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Powerline Carrier System Transmitter for Audio (Music/Speech)
Power line carrier system is common in home appliances networking. One benefit of using this kind of transmission line is that we don’t have to deal with additional wiring for data or signal...
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Compact 3W BTL Audio Power Amplifier TDA7056
Bridge-tied-load (BTL) configuration in an amplifier is basically a H-network with the loud-speaker as the “bridge” between two active valve or switcher. This configuration allow a full alternating...
View ArticleBasic Complementary (Push-Pull) Power Amplifier Circuit
This amplifier circuit is very popular audio power amplifier circuit type. We call it a complementary since the final transistors is an NPN-PNP pair, each with the same characteristics. This circuit...
View ArticleVoltage-Controlled Attenuator (Volume Control) Using FET
Using the circuit shown in the schematic diagram below, we can control the low-level audio signals with ±3V variable DC voltage. This attenuator circuit uses a field effect transistor (FET) to shunt...
View Article60-dB Range Compressor For Audio
A compressor circuit shown in the schematic diagram below can produce consistent output of 1.4V P-P over entire 60dB range that is very useful for audio level/volume stabilization. As the main...
View ArticleTelephone Circuit: Music On Hold
Some costly efforts have been made to shorten the waiting time for all kind of services in the call center or other business, but many customers still complaining about the long waiting time, so other...
View ArticleBinaural Synthesizer/Mono to Stereo Converter for Small Speaker/Phones
When we connect a mono audio output into a stereo headphone (simply by paralleling it), we would hear the sound with all of its components comes from one point, and the worst, that point is located...
View ArticleTremolo Effect Circuit for Electric Guitar or Other Musical Instruments
Tremolo circuit is a kind of sound effect. We can see this type of effect is applied in guitar effect pedals. Tremolo effect is produced if we modulate the amplitude of an audio signal. The shape of...
View ArticlePC (Audio) Signal Generator Using RS232 Port
Using an RS232 port, we can generate square wave oscillation when transmitting data, and this can be “misused” as signal generator (square wave generator). This is a PC Signal generator produce a...
View ArticleDigitally Controlled Gate for Audio Signals
This circuit can be applied in digital-controlled audio application, for example to select the active input line by a micro controller. For such purpose, we can build three units of this circuit and...
View ArticlePowerline Carrier System Transmitter for Audio (Music/Speech)
Power line carrier system is common in home appliances networking. One benefit of using this kind of transmission line is that we don’t have to deal with additional wiring for data or signal...
View ArticleCompact 3W BTL Audio Power Amplifier TDA7056
Bridge-tied-load (BTL) configuration in an amplifier is basically a H-network with the loud-speaker as the “bridge” between two active valve or switcher. This configuration allow a full alternating...
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