LA3161 based Preamplifier circuit with explanation


Posted on Feb 6, 2014

Preamplifiers are used to amplify low level signals such as those from mikes, tape heads before they are fed into power amplifiers. Power amplifiers are generally less sensitive. Frequency response also can be suitably trimmed and modified at preamp stage. LA 3161 is one of those widely used in tape decks and amplifiers as a stereo preamplifier. B


LA3161 based Preamplifier circuit with explanation
Click here to download the full size of the above Circuit.

lock Diagram is shown in Figure. LA 3161 has two low noise preamplifiers with good ripple rejection on chip catering to stereo applications. External part count is low and Single In line (SIL)(Figure 43) package makes mounting easy. Wltile the operating voltage is 9V, the IC can tolerate voltages up to 18V. Typical input resistance is WOK and output resistance is 10K with an open loop gain of78dB. Block diagram of the IC is given below. Input is given at Pin 1 and 8, output is taken at Pin 3 and 6, and negative Feedback is given at Pin 2 and 7. Power is at Pin 5 and Pin 4 is the ground terminal. There is an internal voltage regulator. Ready made PCBs, even populated PCBs are available using this very useful IC. You can still build one, with a Veroboard provided proper care is taken about the ground returns. It simply means that one should not connect ground terminals of output and input at the same place. This will create serious oscillations and normal hobbyist will be left in the woods. Please read general instructions for working with amplifiers in the end.




Leave Comment

characters left:

Related Circuits

  • New Circuits

    .

     


    Popular Circuits

    HiFi stereo preamplifier with tone control
    Stereo Audio Power Meter
    mosfet Reverse polarity protection
    motorcycle headlight with single spdt relay
    Long Range Cloner
    microcontroller complete code midi emulated ps 2 keyboard
    TDA7000 fm radio integrated circuit design
    A common car inverter circuit diagram and working principle



    Top