2 x 60 W audio amplifier circuit

jacky July 1, 2010 47 Comments
Description. The circuit diagram shown here is of a 2 x 60 Watt stereo amplifier based on the LM4780 from National Semiconductors. LM4780 is a superb audio amplifier IC capable of delivering 60W Rms power output / channel into 8 ohm speakers. The LM4780 has very low total harmonic distortion (less than 0.5% at full output) and has a power supply rejection ration (PSRR) of 85 dB. The IC requires very few external components and has a built in...
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Motional feed back amplifier

jacky April 29, 2010 121 Comments
This versatile amplifier circuit is designed and submitted by Mr Seetharaman Subramanian from Chennai . The full credit of this article goes to him and we are very proud to publish this fabulous circuit here. Seetharaman’s description about the circuit. This concept has appeared long back in Practical Electronics a UK based Magazine. Based on this concept I designed this circuit during 1981 to 1986 with lots of field trials and modifications, the design was frozen in 1986. I...
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3 input microphone preamplifier

jacky April 28, 2010 5 Comments
Decription. The circuit given here is of a three input mic mixer cum preamplifier using the IC LM348. The LM348 is a high gain, internally compensated quad operational amplifier with a class AB output stage. The IC has very low input supply current drain (0.6mA/ opamp) and operates from a dual power supply. Out of the four op-amps inside the IC LM348, IC1a, IC1b and IC1c are wired as non inverting amplifiers and they serve as the input amplifiers...
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5 band graphic equalizer using LA3600

jacky April 22, 2010 13 Comments
Description. The graphic equalizer shown here is based on the IC LA3600 from Sanyo Semiconductors. LA 3600 is a single integrated single Op-amp, 5 band graphic equalizer IC which is very suitable for applications like portable stereo, radio sets, home theater systems, car audio systems etc. The LA3600 can be operated from anything between 5 to 15V DC and is extremely stable to capacitive loads. In the circuit capacitors C1, C3, C5, C7 and C9 are used to fix...
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Baxendall tone control circuit

jacky April 20, 2010 38 Comments
Description. This simple tone control circuit is designed based on the famous Baxendall tone control circuitry. The circuit given here can give a maximum cut or boost of around 12 dB at 10 KHz (treble) and 50Hz (bass). Also, both bass and treble can be independently adjusted. Transistor Q1 (BC109) and its associated components (R1, R2 and R3) form an emitter follower which is the input stage. The voltage gain of this input stage is around 1 and it...
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Low cost Mic Mixer

admin April 21, 2010 3 Comments
Description This is the schematics of a low cost mic mixer that can be assembled from the components in your junk box.This two channel mike mixer is designed for handling high impedance dynamic microphones.Transistor Q1 can be any general purpose pnp transistor like BC177 or BC157B. Resistor R5 biases the transistor while R3 and R4 provides channel isolation. How ever better the transistor quality better the performance.  C1 and C2 performs the job of input coupling and DC isolation...
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USB sound card

jacky April 7, 2010 13 Comments
Description. Designing and building a USB sound card is no longer a head ache because we have got the PCM 2702 integrated circuit from Texas Instruments. The PCM2702 is an integrated 16 bit digital to analog converter that has two digital to analog output channels. The integrated interface controller of PCM2702 is compliant to the USB 1.0 standards. The IC can handle sampling rates of 48 KHz, 44.1 KHz and 32 KHz. The IC also has a number of...
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40W amplifier using TDA1514

jacky April 7, 2010 16 Comments
Description. Many electronic circuits dealing with audio amplifier circuits have been published here. This is just another one and here we use the TDA 1514 high performance hi-fi amplifier from Philips. The IC has a bunch of useful features like thermal protection, mute-standby facility, low harmonic distortion etc. The amplifier operates from a dual +25/-25 V DC power supply and can deliver 40Watts output power to an 8 ohm speaker. The audio signal to be amplified is fed to...
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3 way active cross- over network

jacky April 7, 2010 12 Comments
Description. Here is the schematic of a 3 way active cross- over network circuit that finds a lot of application in audio amplifier systems. The heart of this circuit is National Semiconductor’s IC LF353 which is a dual JFET input operational amplifier with internally compensated input offset voltage. The IC LF353 has high bandwidth, low offset currents, and low input bias current due to the JFET based input stage. The working of the circuit is very simple and straight...
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2 x 32 Watts stereo amplifier

jacky March 8, 2011 56 Comments
Description. The circuit given here is of a 2 x 32 Watt stereo amplifier using the famous TDA2050V IC from ST Microelectronics. The TDA2050V is an integrated monolithic 32 watt class AB audio amplifier IC available in the Pentawatt package. The IC has lot of good features like low distortion, short circuit protection, thermal shut down etc. Two TDA2050V ICs are used here, one for each channel. For each channel the input audio signal is fed to the non-inverting...
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