AmplifierCircuits

A preamplifier circuit suitable for high impedance type electric guitar pickups is given here.The circuit is based on a uA 741 op-amp (IC1).The IC1 is wired as a non-inverting amplifier.The POT R1 can be used as a volume controller.The POT R6 can be used as tone controller.The switch S1 is used  to produce “brilliant” or “soft” tonal effects. Assemble the circuit on a good quality PCB or common board. The amplifier can be powered from a 12V battery  or 12V DC power supply. Up to 24 V DC can be used to power the circuit.i recommend 12 V DC. The IC 1 should be mounted on an IC base  Circuit Diagram: Guitar pre-amplifier

This small amplifier was intended to be used in conjunction with an electric guitar to do some low power monitoring, mainly for practice, either via an incorporated small loudspeaker or headphones. The complete circuit, loudspeaker, batteries, input and output jacks can be encased in a small box having the dimensions of a packet of cigarettes, or it could be fitted also into a real packet of cigarettes like some ready-made units available on the market. This design can be used in three different ways: Mini Portable Guitar Amplifier Max output power:  1.5W @ 9V supply - 8 Ohm load; 60mW @ 3V supply - 8 Ohm load Frequency response:  Flat from 20Hz to 20kHz Total harmonic distortion @ 100mW output:  0.2% Max input voltage @ 3V supply:  8mV RMS Minimum input voltage for Fuzz-box operation:  18mV RMS @ 3V supply Current consumption @ 400mW and 9V supply:  200mA Current consumption @ 250mW and 9V supply:  150mA Current consumpti...

General Description This design adopts a well established circuit topology for the power amplifier, using a single-rail supply of about 60V and capacitor-coupling for the speaker(s). The advantages for a guitar amplifier are the very simple circuitry, even for comparatively high power outputs, and a certain built-in degree of loudspeaker protection, due to capacitor C8, preventing the voltage supply to be conveyed into loudspeakers in case of output transistors' failure. The preamp is powered by the same 60V rails as the power amplifier, allowing to implement a two-transistors gain-block capable of delivering about 20V RMS output. This provides a very high input overload capability. Features: Sensitivity: 35mV input for 40W 8 Ohm output 42mV input for 60W 4 Ohm output Frequency response: 50Hz to 20KHz -0.5dB; -1.5dB @  40Hz; -3.5dB @ 30Hz Total harmonic distortion @ 1KHz and 8 Ohm load: Below 0.1% up to 10W; 0.2% @ 30W Total harmonic distortion @ 10KHz a...