Introduction: EE 221 Electrical Guitar Amp

The goal of this project was to build a guitar amp along with a filter to single out a specific string of an electric guitar. The specific string this project focuses on is string G (196Hz). A Chebyshev filter is used to single out the G string while a simple op amp and other passive components are used for the amplifier.

Step 1: Parts List

Filter Parts

  1. 160 kOhm resistor x2
  2. 47 nF capacitor x10
  3. 5.6 MOhm resistor
  4. 6.2 MOhm resistor
  5. 2.2 MOhm resistor x2
  6. 1.8 MOhm resistor
  7. 43 Ohm resistor
  8. 47 Ohm resistor
  9. 110 Ohm resistor
  10. 120 Ohm resistor
  11. 150 Ohm resistor
  12. 238 kOhm resistor x2
  13. 910 kOhm resistor
  14. Operational Amplifier x5

Amplifier Parts

  1. 22K 1/4W Resistor
  2. 10µF 25V Electrolytic Capacitor
  3. 100nF 63V Polyester or Ceramic Capacitor
  4. 220µF 25V Electrolytic Capacitor
  5. TDA7052 Audio power amplifier IC
  6. 6.3mm Stereo Jack sockets
  7. 8 Ohm Loudspeaker
  8. 9V PP3 Battery or 3V Battery

Step 2: Building the Amplifier

The amplifier involves following a simple schematic as seen from the picture. Only one jack is necessary, the other is optional. Pin 1 holds the connection between the battery and C2/C3. C1 and R1 should connect to pin 2 of the IC. Pins 3 and 6 should be connected to ground. Pins 5 and 8 are connected to the jack. From the jack, the speaker is connected.

Here is a video of the amplifier at work:

Step 3: Building the Filter

The filter design is a little more compleicated than the amplifier but still easy enough to construct on a breadboard. Here is a link to the OP 37 pin out chart:

Here is an example of a single op amp connection on a breadboard:

Above is also an example of the frequency you should expect if you measure the frequency response.

An ideal circuit was made using a free program, QUCS, a bode plot was created from that and is shown above.