Stereo sound level meter / Stereo VU meter Description. The circuit shown here is of a stereo sound level indicator/VU meter  using the IC TA7666P from Toshiba. The TA7666P consists of 2 inverting amplifiers, ten comparators and a reference voltage generator. The turn on levels for TA7666P are 5dB, 5dB, 3dB, 3dB and has a […]
Description. Here is the circuit diagram of a simple 3 channel audio splitter based on the IC NE5532. NE5532 is a dual internally compensated low noise opamp from Fairchild semiconductors. It has a high small signal and power bandwidth, making it well suitable for high quality audio applications. Here the IC1 is wired as a
Description. Many low pass filter circuits for subwoofer are given here and this is just another one. The circuit given here is based on the opamp TL062 from ST Micro electronics. TL062 is a dual high input impedance J-FET opamp which has very low power consumption and high slew rate. The opamp has excellent audio
Description. This is just another 20W audio amplifier circuit , but this time based on the LM1875 audio amplifier IC from National Semiconductors. With a 25V dual power supply LM1875 can deliver 20W of audio power into a 4 ohm speaker. The LM1875 requires very less external components and has very low distortion. The IC
Description The audio amplifier shown here is based on the TDA7240 IC from ST Microelectronics. The TDA 7240 is an integrated audio amplifier IC that can deliver 20 watts of audio output power into a 4ohm load. The IC has minimum external parts count and is available in the 7 pin compact Heptawatt package. The
Description. Here is the circuit diagram of an excellent stereo preamplifier with tone control using the IC TDA1524 from Phillips. The IC requires very few external components, has very low noise and has a wide power supply voltage range. POTs R1 to R4 can be used for controlling the volume, balance, bass and treble respectively.
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
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
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
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
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,
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
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
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
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
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
Description. A lot of electronic circuits in the domain of audio amplifiers are already been published here. This circuit is a little different because it is a four channel amplifier. Each channel of this amplifier can deliver an output of 15Watts into a 4 ohm speaker. The amplifier can be operated from a single 12V
Description. The schematic of an automatic cooler fan for audio amplifiers is given here. The circuit automatically switch ON the cooler fan whenever the temperature of the heat sink exceeds a preset level. This circuit will save a lot of energy because the cooler fan will be OFF when the amplifier is running on low
Description. When the amplifier is switched on, the speaker gets popped up by a high voltage and you can hear a loud thud sound from the speaker. This stuff is very harmful to the speaker and it drastically reduces the speaker’s life. The circuit shown here connects the speaker to the power amplifier output only
Description. This is the circuit diagram of a two channel audio line driver using the high performance dual opamp IC TSH22 from ST Microelectronics. The 25 MHz bandwidth, low distortion and high output current of the IC makes it possible to drive medium impedance loads at a high level of modulation. Here both of the
Description. Here is the circuit diagram of a passive DX bass circuit that can be used with almost all audio amplifiers. This circuit is designed by Mr. Emmanuel Chipula (emmanuel@windowshoppingmalawi.com) from Malawi and was sent to us for publication.We tested this circuit in our lab and the result was fine.Full credit of this circuit goes
Description. Here is the circuit diagram of a simple subwoofer filter that can be operated from a 12V DC supply. Such a circuit is very useful in automobile subwoofer applications. The circuit is nothing but a low pass filter whose pass frequency can be adjusted between 60 to 160 Hz. The circuit is designed around
Description. Here is the circuit diagram of an opamp based subwoofer filter. Audio frequencies below 200Hz are considered to be in the subwoofer range. So a subwoofer filter will be essentially a low pass filter with a cut off frequency of 200Hz.The working of this straight forward circuit is as follows. The left channel of
Description. This circuit is designed in response to a request made by Mr Vignesh. What he requested was a circuit for recording and playing voice. I think this circuit is enough for the purpose. This circuit is based on the IC ISD1020A from ISD. The ISD1020A is a CMOS single chip record/playback device. The chip
Description. Here I present a very simple and powerful headphone amplifier using OPA134. In addition to the IC OPA134, the circuit uses only few passive components and can easily generate a lot of sound from even the most inefficient headphones and there will be no compromise for the quality. OPA134 is low noise, low distortion
