Mini Guitar Amp

This mini guitar amplifier is based on the Ruby Amp (runoffgroove.com). It delivers ½ Watt at 9V, being perfect as a home practice amp. It has gain and volume control, offering a very dynamic sound on any speaker.
Steps

Created by DHEA
Status: Active
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Designators and components Step 2 of 4

COMPONENTS

Capacitor
C1    47n       47NF 100V 5% POLYESTER FILM BOX TYPE CAPACITOR
C2    47n       47NF 100V 5% POLYESTER FILM BOX TYPE CAPACITOR
C3    220u     220UF 25V ELECTROLYTIC CAPACITOR 8X12MM
C4    100n     100NF 100V 5% POLYESTER FILM BOX TYPE CAPACITOR
C5    100u     100UF 35V ELECTROLYTIC CAPACITOR 6X11MM
C6    100n     100NF 100V 5% POLYESTER FILM BOX TYPE CAPACITOR (Optional)

Diode       
D1    LED       LED 3MM GREEN  

Resistor
R1     1M        1M OHM 1/4W 1% METAL FILM RESISTOR
R2     3.9k      3.9k OHM 1/4W 1% METAL FILM RESISTOR
R3     10         10 OHM 1/4W 1% METAL FILM RESISTOR
R4     2.2k      2.2k OHM 1/4W 1% METAL FILM RESISTOR

IC
Q1    2N5457     SMD SOT-23 2N5457 JFET N-CHANNEL TRANSISTOR
(Q1 SMD TRANSISTOR PCB)
IC1   LM386       LM386 AUDIO AMPLIFIER IC
(IC1 Socket    8 PIN DIP IC SOCKET ADAPTOR)

Potentiometer        
VOL           10k-B       10k OHM Lin POTENTIOMETER
GAIN         1k-B         1K OHM Lin POTENTIOMETER
 

PCB

 

SCHEMATIC

 

BOOST MOD

Place a 100nF capacitor on C6 and connect a switch to Sw.

 

GENERAL DESCRIPTION OF COMPONENTS

Resistors

Use a multimeter or the color bands to obtain the resistance value. Resistors do not have polarity, you can place them in any direction.

Electrolytic capacitors

Electrolytic capacitors have their value printed on them. The negative polarity pin is indicated by a white strip along the can. They also have a longer leg indicating the positive pin. The maximum voltage rating never can be exceeded, make sure you are using at least double voltage rating than your power supply. For example, if you are using a 9V power supply, use a electrolytic capacitor with at least 18V maximum voltage rating.

Polyester capacitors

Polyester capacitors have their value marked with three numbers. Read as picofarads (pF), the first two are the 1st and 2nd digits and the third is the multiplier code. These capacitors do not have polarity, you can place them in any direction.

Integrated Circuits

Integrated Circuits (ICs) have their model printed on them. A notch half-circle or a dot indicates the correct position on the PCB.

Diodes

Diodes have their model printed on them. The polarity (cathode) is indicated by the ring near the side. This ring is also marked on the PCB.

Led diodes

Led diodes have polarity, the cathode is indicated as a flat surface on the side of the diode and also it is the shorter led. On the PCB, the cathode is marked as a flat side and anode as a round side.

Transistors

Transistors are three terminals components and their model is printed on them. To indicate the correct orientation, one side of the transistor is flat and the other one is round.

Potentiometers

Potentiometers have their resistance value marked on them. They are marked with A, B or C for logarithmic, linear and reverse logarithmic, respectively.