Selectable sensitivity Preamplifier


Posted on Jan 13, 2013

Most audio amplifier systems must have preamplifiers with many different characteristics. These include high-gain linear response for magnetic microphones, low-gain linear response for tuners, and high-gain RIAA equalization for magnetic phone cartridges. To meet this broad requirement, most amplifier designers include a single universal preamplifier circuit. Basically a high-gain linear amplifier, its characteristics can be altered by switching alternative resistor filter networks into its feedback system.


Selectable sensitivity Preamplifier
Click here to download the full size of the above Circuit.

For example, when the selector switch is set to the Mag phono position, alternative input sources can be selected by S1-a, and appropriate linear-response gain control feedback resistors 220K, 470K, and 1M are now selected by S1-b. Those feedback resistor values are selected between 10 kilo ohms and 10 megohms to suit individual listener tastes. Circuit gain will be proportional, to the feedback resistor value.




Leave Comment

characters left:

New Circuits

.

 


Popular Circuits

1,5V Earphones Audio Amplifier
Simple Indicator for Dynamic Limiter Schematic Diagram
short circuit protection for balanced
buzzer circuit diagram
A Canon DSLR cable shutter release
Original 2N2/40 Schematic Diagrams
100 V output with shunt regulationl
Car battery charging circuit diagram



Top