Category Archives: Audio

Audio schematic diagram


This is the simple and low cost 3 channels mini audio mixer circuit diagram. This circuit supplied using 9V power supply. There are high/low-sensitivity switchable inputs for each input channel and each channel used low noise and high gain transistor of BC550C.


Here the 35W power audio amplifier circuit based on LM391. Inductor L1 is constituted by 20 coils of wire, with thickness 0.9mm, round resistor R16. The transistors Q3-4 are the final amplification section, it should be placed on heatsink. If are used the Q3-4 in packing TIPxxxx they can be Read more…


18W Audio Amplifier Circuit Electronic

This is the circuit diagram of 18W audio amplifier. The circuit is quite simple and inexpensive to built. It uses a pair of power transistor TIP41A and TIP42A for single channel operation. The power supply used for this circuit is dual polarity (splitted) power supply, use center tap transformer to Read more…


DS1669 Digital Variable Resistor

The DS1669 is an electronic digital rheostat manufactured by Dallas Semiconductor. This component has a function similar to digital variable resistor/potensiometer which can be operated by push the buttons. You can adjust the audio volume, LCD contrast, frequency, etc. by using two buttons instead of a common potentiometer/trimpot. This circuit Read more…


2 Way Speaker Box Design Illustration

This is 2 way speaker box design for audio system. I’ve used this design for my home audio system, the sound quality is good. Two speakers used for this speaker box that are tweeter / high frequency speaker and woofer / low frequency speaker / subwoofer. Alternatively you may replace Read more…


Stereo Speaker Protection Circuit Electronic

This is the speaker protection circuit, provides stereo speaker protection and prevents switch-on clicks and DC components on the output of the amplifier connected.


Sensitive hearing aid circuit electronic

This is the circuit diagram of electronic hearing aid featured with sensitive sound detection and energy saving, so this hearing aid will work in the long term with a 9V batery battery cycle. The common hearing aid circuits consume the battery energy continuously once they are turned on. This smart Read more…


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