This is an active stereo tone control circuit using very well known op-amp IC of TL072. The circuit include mic pre-amp and mixer control. In this design, we have two inputs: one for line (stereo), one for microphone and has control of the three audio frequency (high/treble, medium and low/bass). It also provide balance control… Read More »
This is the simple project of small sound amplifier for ears or often called hearing aid device or hearing loss amplifier. This circuit was already tested on some patients and give significant improvement in the hearing ability to the patients. It consumes a very small amount of power within the range of 10 milliwatts. Furthermore,… Read More »
This is the stereo headphone amplifier circuit diagram, built based LM4809. This circuit can be used for stereo headphone amplifier circuit for home audio system, microphone preamplifier, personal computers and PDA headphone amplifier and more. The LM4809 is known as a stereo audio power amplifier capable of delivering 105mW per channel of continuous average power… Read More »
This is a simple audio pre-amplifier circuit using single transistor 2N3904. This easy circuit provides good gain to weak audio signals such as electret microphone. Use it in front of an RF oscillator to make an RF transmitter that’s very sensitive to sound. Power supply used for this circuit is wide range from 3VDC to… Read More »
Here is the dynamic microphone amplifier circuit diagram. This circuit should be perfect for dynamic microphone… Dynamic microphones are versatile and ideal for general-purpose use. They use a simple design with few moving parts. They are relatively sturdy and resilient to rough handling. They are also better suited to handling high volume levels, such as… Read More »
This a simple stereo electret microphone pre amplifier circuit. The below design diagram is the design for single channel, but the design of PCB layout is for stereo design og electret mic pre amp. For maximum performance, better quality, use solid capacitors or film capacitors and metal film resistors (1% tolerance). schematic diagram:
This is the circuit diagram of low impedance microphone amplifier. The circuit designed for use with low impedance (~200 ohm) microphones. It will work with regulated voltages between 6-30VDC. If you don’t build the impedance adapter part with T1, you get a microphone amplifier circuit for higher impedance microphones. In this case, you should directly… Read More »
LM4809 Datasheet Document. Boomer audio power amplifiers were designed specifically to into 32 0.1% (typ) provide high quality output power with a minimal amount of external components. Since the LM4809 does not require bootstrap capacitors or snubber networks, it is optimally suited for low-power portable systems.
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 electronic hearing aid saves battery… Read More »