Mini Portable Guitar Amplifier

Can be fitted into a packet of cigarettes

Also suitable as Fuzz-box

Circuit diagram:

Mini Guitar Amplifier


R1______________22K  1/4W Resistor

C1______________10µF  25V Electrolytic Capacitor
C2_____________100nF  63V Polyester or Ceramic Capacitor
C3_____________220µF  25V Electrolytic Capacitor

IC1__________TDA7052  Audio power amplifier IC

J1,J2__________6.3mm  Stereo Jack sockets (switched)

SPKR___________8 Ohm  Loudspeaker (See Notes)

B1________________9V  PP3 Battery or
                  3V  Battery (2 x 1.5V AA, AAA Cells in series etc.)

Clip for PP3 Battery or socket for 2 x 1.5V AA or AAA Cells


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:


Technical data:

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 consumption @ 60mW and 3V supply: 80mA

Quiescent current consumption: 6mA @ 9V, 4mA @ 3V supply

Fuzz-box current consumption: 3mA @ 3V supply