tone decoder
For some applications it is important to have a tone decoder with narrow bandwidth and fast response time. This can be accomplished by the dual time constant to...
Stereo demodulator
This circuit uses a single IC LM1310 to proyide left and right outputs from a composite MPX stereo signal. Oscillator adjust Rl is set for 76 kHz (19 kHz at pin...
Sounds from the IC IT82207
This circuit is able to take you to the world of the Wild West. For this it uses the integrated 18-pin IT82207 (IC1) of Holtek, which literally takes care of ev...
Mono audio panoramic interference (pan pot)
The circuit spectator interference enables implantation mono sound at any point between stereo speakers. When P1 is in the middle of his journey, there is stren...
Low energy consumption audio signal generator
On those occasions when we want to see if an amp works, the best tool we can use is a source of acoustic signal with a frequency around the 1 kHz. These charact...
Hi-Fi stereo Preamplifier with tone controls
The circuit is based on the known chip TDA1524, which is an integrated control Volume, Bass, treble, and Balance. These arrangements are made through 4 potentio...
Ultrasonic Bat reciever
You won't be disappointed with the performance of this sensitive ultrasonic receiver. It can let you listen to bugs, bats, engines, and virtually any other sour...
Stereo Preamplifier with balance and loudness
The circuit of preamplifier use the 5533 chip and features a combination of controls balance and volume. Due to the nonlinearity of the human auditory system, l...
Fully adjustable preamplifier
This circuit is a audio preamplifier tha has balance, tone and loudness controls. It should be suitable as an example of good design for audio application.
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RIAA preamplifier CA3410
This circuit has read the RIAA equalization, tone controls, and adequate gain to drive most power amplifiers conunercial by using CA3410 op amp BiMOS. Total har...
Automatic audio fader circuit
The automatic fader drops at the background music while the narration is in place. The control input through RIO, a preset audio level control, into an emitter-...
4 channel audio mixer with TL074
This circuit can be used as a mixer and a stereo track four. The quad op-RNAP IC gives a little gain for each track, the pan control provides panning between on...
Audio input selector circuit (4416 CMOS)
CMOS switches are used directly to select the entries in the audio circuits, it can introduce unacceptable levels of distortion, but if the switch is included i...
4 microphones mixer circuit with TL081
A TL081 op amp is used as a high impedance to low. converter and a signal mixer. The input impedance is about 1 megohm and the output impedance is about 1 kohm....
One transistor audio mixer (2N3563)
This circuit mixer has an internal amplification with 2N3563 transistor. The two input signals can be independently controlled by VRI and VR2. The VR3 balance c...
Active crossover circuit with TL074
An audio source, like a mixer, preamp, EQ, or a recorder, is fed to the input of the Electronic Crossover Circuit. This signal is either AC or coupling, dependi...
Tone Doorbell circuit
When the door is pushed, you hear a whisper that "slide up" to a higher frequency. The oscillator frequency is determined by AF coupling capacitance, C 1 and th...
Q-multiplier filter circuit
This circuit is selective for the tuning adjustment between two closely spaced tones audio. The frequency is dependent on the selective value capacitors and res...
Overload speaker protection circuit
The circuit input is taken from the terminal loudspeaker or amplifier output jacks. If the right channel is large enough to charge C1 to a potential which excee...
Audio compressor circuit
The amplifier drives the base of a common emitter PNP MPS6517 operating with a voltage gain of about 20. RL control varies the quiescent point of the transistor...