Universal Audio Line Amplifier

Posted on Mar 11, 2013

A line amplifier is always a useful unit to have around, whether it is for matching a line signal or raising

Universal Audio Line Amplifier
Click here to download the full size of the above Circuit.

its level somewhat. This might be needed during a recording session or with a public-address system. Furthermore, a line mixer can be constructed from a number of these amplifiers. The input of the amplifier is high-voltage proof. The output impedance is low. The circuit is a conventional design: two dc-coupled stages of amplification are separated by a threefold Baxandall tone control system. The volume control at the input is conspicuous by having its "cold" side connected, not to ground, but to the output of the first amplifier. Because the signal there is out of phase with the input signal, the amplifier obtains negative feedback via PI. The amplification is therefore inversely proportional to the magnitude of the input signal. Thus, it is possible for the amplifier to accept a wide range of input levels. It is quite possible to input a signal taken directly from the loudspeaker terminals of a power amplifier. The supply voltage is 24 V. At that voltage, the amplifier draws a current of about 4 mA. If several amplifiers are used in conjunction (as, for instance, in a mixer panel), the various supplies (+ and + + in the diagram) can be interlinked. Capacitors C17 and C18, and resistor R7 don"t need to be duplicated in that case.

Leave Comment

characters left:

New Circuits



Popular Circuits

Negative Voltage from single positive power Supply
Simulated inductor
Rf probe for vtvm
Car Parking Sensor schematic
remote control circuit through radio
sine wave generation with fast pwm mode 2525
Video Amplifier Circuit for Camera PCB
led lights using analog flip flop circuit diagram
LV8741V PWM stepping motor driver electronic project circuit design
For driving the power supply circuit of the sensor bridge