Tag Archives: pre amplifier

55MHz Scope Sensitivity Amplifier

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Scope sensitivity amplifier is a vital front-end signal processing for every scope instruments. The function of this circuitry is simple: amplify the signal with a consistent/stable gain without altering the waveform. A stability of its gain make it possible to make a precise volts/div scaler with no drift in time… Read more »

HiFi pre-amplifier circuit diagram with low noise output

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This is a HiFi pre-amplifier circuit diagram with low noise output. Very wide range frequency from about 10Hz until up to 100Khz  will be gained by this preamplifier for maximum audio performance. Here the response of the preamp’s frequency and phase: Here the diagram of total noise at output, measured… Read more »

Simple Mic Pre-Amp based LM358 circuit diagram

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Here the simple audio mic pre amplifier circuit based on single IC LM358. The circuit is very simple, inexpensive and easy to built. Component Parts List:R1, R3, R4 = 10KR2 = 1KR5 = 100K-1M PotensiometerC1 = 0.1uFC2 = 4.7uF/16VIC1 = LM358 dual op-amp single supplyMic = Electret Microphone Notes: Use… Read more »

Guitar Pre-Amp with JFET 2N5457 circuit diagram

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Designed by Don Tillman, this guitar pre-amp circuit design is dedicated for people who don’t like op-amps. This circuit is a discrete JFET pre-amp design, use 2N5457 as the main component. It has low noise, low distortion, low feedback, overloads gracefully, is small, etc. Overall gain is 3db (2X) or… Read more »

Current Amplifier Using CA3140 Op-Amp

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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… Read more »

Balanced Input Microphone Pre-Amplifier, High Quality Audio For Long Distance Wiring

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Balanced input has three connections, ground, positive signal, and negative signal. When we trace the signal using oscilloscope, if we take the ground as the reference, then the negative signal and the positive signal has similar shape but with inverted polarity. If we measure the signal between positive and negative… Read more »

Battery Powered Electret Microphone Pre-Amplifier

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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… Read more »

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

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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… Read more »

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

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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… Read more »