English ManThis pedal emulates a VOX AC amplifier working at the limit. It has the ability to work as a clean boost or an overdrive depending on the volume and gain control, offering a great dynamic response and open sound.
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, 1N34A..) will produce softer distortion, the silicon (1N914 , 1N4148...) harder and the leds more fuzz and crunch. You can also experiment with different combinations (symmetric o asymmetric). Use the diode sockets and easy change the diodes to find the sound you are looking for. This project already includes a diode selector, you can also use a rotatory selector to include more combinations.
For more information about diode modifications please take a look at 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 to 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 (their codes are indicated in the BOM table). 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.
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 lines.
Potentiometers can be mounted directly on the PCB. For a correct orientation, the potentiometer shaft is marked on the PCB.