Mini Guitar AmpThis mini guitar amplifier is based on the Ruby Amp (runoffgroove.com). It can yield 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.
DESIGNATORS AND COMPONENTS Step 3 of 5
GENERAL DESCRIPTION OF COMPONENTS
The resistors are ¼ Watt metal type. You can either use a multimeter or the color bands to obtain their values. Resistors don’t have polarity; you can assemble them in any direction.
Electrolytic capacitors have the value printed on them. The polarity is also is marked for the negative lead, additionally the longer leg is the positive and shorter the negative. Assemble the electrolytic capacitor according with the positive polarity (+) marked in the PCB, that is, the longer leg of the capacitor is passed through the pad marked with +.
The polyester capacitors have three numbers, read as picofarads (pF), the first two are the 1st and 2nd digits and the third is the multiplier code. This type of capacitors doesn’t have polarity; you can assemble them in any direction.
Diodes have their type number marked on them. This two terminals component has polarity; a ring near the side indicates the cathode. This ring is marked as a line to indicate the correct polarity in the PCB.
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.
Integrated Circuits have their name and model printed on them. A notch half-circle or a dot indicates the correct position that the IC needs to be assembled on the PCB.
Transistors are three terminals components and their model and name are printed on them. To indicate the correct assembling position one side of the transistor is flat and the other one is round, in the same way, the PCB is marked with round and flat side.
Potentiometers can be mounted directly on the PCB. For a correct orientation, the potentiometer shaft is marked on the PCB.