Stereo balance indicator

john April 7, 2010 1 Comment
Description. This is one of the simplest stereo balance indicator circuit that you can have. The circuit will give a visual indication (using two LEDs) proportional to the difference in balance between the left and right channels of a...
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Dynamic microphone amplifier using transistors

john April 7, 2010 3 Comments
Description. Here is the circuit diagram of a simple dynamic microphone amplifier using two transistors. The amplification factor of this circuit is around 150 and can handle signals from 50Hz to 100Khz.These features make it ideal for audio applications....
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40W audio amplifier

john April 7, 2010 8 Comments
Description. This is a very excellent 40W power amplifier design using TDA2030 IC and two transistors. The circuit employs only few components and does not require a dual power supply. The input signal is coupled to the non inverting...
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Preamplifier for dynamic microphones.

john April 7, 2010 3 Comments
Description. Here is a low noise preamplifier design for dynamic microphones. The circuit is based on the uA739 IC from Fairchild Semiconductors. uA739 is a dual audio operational amplifier with high gain and excellent stability. Out of the two...
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FET based audio preamplifier.

john April 7, 2010 7 Comments
Description. This is the circuit of a based audio preamplifier which has very low noise. One FET and one BJT are used in this circuit. The audio signal to be amplified is coupled to the base of FET Q1...
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Jet engine sound generator

john January 18, 2011 21 Comments
Description. This jet engine sound generator circuit is based on the sound generator IC HT2844P from Holtek Semiconductors. This particular IC can make four sounds namely low speed sound of jet engine, high speed sound of jet engine, missile...
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250mW audio amplifier

john April 7, 2010 11 Comments
Description. Here is a very simple three transistor audio amplifier circuit that can deliver 250mW to a 8Ohm speaker. Complementary transistors BC337 and BC227 (Q3 and Q2) are used as the output pair. Transistor Q1 (BC 547) acts as...
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10W amplifier using TDA2003

john September 28, 2017 22 Comments
Description. Here is the circuit diagram of a 10W audio amplifier using the popular TDA2003 IC from SGS Thomson. The IC can easily deliver 10W to a 4 Ohms load at 18V DC supply voltage. The IC can be...
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Single transistor audio mixer.

john April 7, 2010 3 Comments
Description. Many audio mixer circuits have been published here. But I think, this one is the simplest of them. This very simple audio mixer circuit uses only one transistor. The base emitter junction of the transistor is biased by...
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Simple 10W audio amplifier

john November 2, 2011 11 Comments
Description. The circuit given below is of a simple audio amplifier that can deliver 12W to an 8 Ohm speaker. Op amp IC TL081 is used as the preamplifier here. Actually any opamp with matching power supply ratings can...
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