EternityThis guitar pedal offers a very smooth type of overdrive similar to the saturation generated by a vacuum tube. It is perfect to play blues and rock, adding a smooth saturation and good sustain.
DESIGNATORS AND COMPONENTS Step 2 of 4
MODIFICATIONS AND EXPERIMENTATION
You can obtain different types of distortion by changing the diodes. The germanium diodes (1N60, 1N270 or 1N34A) will produce softer distortion, the silicon (1N914 or 1N4148) harder and the leds more fuzz and crunch. You can also experiment with different combinations (symmetric o asymmetric). Originally the circuit uses asymmetric configuration, subtitute the jumper for a diode on D4 to change to symmetric. Install the diode sockets on the oposite side of the silkscreen to leave room for the gain potentiometer.
For more information about diode modifications please take a look to www.diystompboxes.com/cnews/mods.html
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.
Potentiometers can be mounted directly on the PCB. For a correct orientation, the potentiometer shaft is marked on the PCB.