Tag «Pre-Amplifier»

Single Transistor Microphone Pre-Amplifier for Both Dynamic and Condenser Type Mics

Condenser microphone and dynamic microphone (moving coil microphone) has different characteristics. For dynamic mics, a biasing current is not needed because the transducer generate the electrical signal. In condenser mics, a bias current is needed to compensate the leakage in the microphone, and because of the pre-amplifier loading that discharge the condenser mic’s electrical charges. …

Two Stage Phono Pre-Amplifier with Very Accurate RIAA Response Curve

To produce a pre-amplifier with accurate RIAA response, this circuit use two stages of amplifier. This circuit is more complex than single op-amp RIAA pre-amp, but the performance is excellent in terms of accurate frequency response. Here is the schematic diagram of the circuit. The circuit uses LM833 high performance op-amp from National Semiconductor, giving …

Gramophone Pre-Amp: A Pre-Amplifier with RIAA Response Curve

Recording Industry Association of Ameria (RIAA) has developed the recording standard of response curve for their recording. This curve is developed to optimize the gramophone recording response for lowest signal-to-noise ratio for gramophone technology. Because the tape recording response is not linear, the pre-amp for gramophone playback pickup should have such  response that restore the …

Current Amplifier Using CA3140 Op-Amp

Current amplifier application need very low input bias current, and CA3140 is one of suitable op-amps for this purpose. The circuit’s schematic diagram is shown in the figure below. In the circuit, low current is supplied at the input potential as the power supply to load resistor RL. When the load current is monitored by …

Battery Powered Electret Microphone Pre-Amplifier

Here is a schematic diagram of electret microphone pre-amplifier using LMV721 op-amp. because the LMV721 has low noise and low power features, it would be an ideal choice for  battery powered microphone preamplifier. The LMV721 is connected as an inverting amplifier. Resistors, R1 =R2 = 4.7k, sets the reference at mid point between VCC = …