Category «Audio»

20 Watts Car Stereo Amplifier Using TDA2004

The main features of this powerful MULTIWATT®  package (a trademark of SGS-THOMSON Microelectronics), a  power amplifier IC chips designed specifically for car radio application, are the high current capability (3.5A) and the capability to drive a very low impedance (down to 1.6R). Here is the schematic diagram of the standard circuit as shown in its …

10-Band Graphic Equalizer Using Gyrator Circuit

Graphic equalizer is a filter which it’s overal frequency response can be adjusted easily by sliding the potentiometer knob, and the potentiometer’s knob positions will naturally mimic the frequency response of the filter, and this is very user friendly. Many methods have been developed by electronic engineers to make audio equalizer, such as Baxandall’s type …

Second Order Butterworth Low-Pass Filter

A second order filters can be constructed using LC (inductor-capacitor) passive circuits,  and they have been implemented for radio frequency for cheap and simplicity. For audio frequency range, unfortunately the size for the inductor and capacitor become too large, space consuming, and the most important is they’re really expensive. Because of this, active filter is …

Voltage-Controlled Stereo Volume Control Using LM13600 OTA

What we can do with a stereo voltage-controlled volume control? There so many things, we can control our audio using a DAC which is controlled by a microcontroller, or we can use mono potentiometer with RC filter to minimize the scratched sound produced by a dirty potentiometer (I see this method in one of SONY …

Baxandall Tone Control Using CA3140 Op-Amp

Operational amplifiers for tone control circuit application require high slew rate, wide bandwidth, high input impedance, and high output current characteristics, and CA3140 is suitable for this purpose. Look at the following tone control circuit’s schematic diagram for the design. The tone control circuit in the figure above use a very popular Baxandall tone control …

Baxandall Tone Control Using Two Transistors

This tone control circuit use very popular Baxandall configuration, a simple circuit configuration that provides boost and cut control in continuous manner. This circuit is very cheap to build, and it’s commonly implemented in commercial product. Here is the circuit’s schematic diagram: The transistors can be substituted by any general audio transistors with small current …

Simple 10 Watts Audio Power Amplifier Using Transistors

This audio power amplifier circuit is simple and robust, and use discrete component available on many electronic part stores. The final transistors use 2N3055 and MJE2055. Here is the circuit’s schematic diagram: The MJE2055 is an npn transistor, but the configuration with TIP42A make the whole combination of TIP42A and MJE2055 are seen as pnp …