Eternity

PCB DESIGNATORS

Capacitors

C1    100n     100NF 100V 5% POLYESTER FILM BOX TYPE CAPACITOR
C2    47n       47NF 100V 5% POLYESTER FILM BOX TYPE CAPACITOR
C3    150n     150NF 100V 5% POLYESTER FILM BOX TYPE CAPACITOR
C4    220n     220NF 100V 5% POLYESTER FILM BOX TYPE CAPACITOR
C5    10u        10UF 50V ELECTROLYTIC CAPACITOR 5X11MM
C7    47u        47UF 25V ELECTROLYTIC CAPACITOR 5X11MM
C8    47u        47UF 25V ELECTROLYTIC CAPACITOR 5X11MM

IC
IC1    NJM4558        NJM4558D IC DUAL OPERATIONAL AMPLIFIER
IC Socket        8PIN IC DIP SOCKET

Diodes
D1    1N914        1N914 SMALL SIGNAL DIODE 200MA 100V
D2    1N914        1N914 SMALL SIGNAL DIODE 200MA 100V
D3    1N914        1N914 SMALL SIGNAL DIODE 200MA 100V
D4    1N914        1N914 SMALL SIGNAL DIODE 200MA 100V

Resistors
R1     3.3k     3.3K OHM 1/4W 1% METAL FILM RESISTOR
R2     1M        1M OHM 1/4W 1% METAL FILM RESISTOR
R3     20k       20K OHM 1/4W 1% METAL FILM RESISTOR
R4     1k         1K OHM 1/4W 1% METAL FILM RESISTOR
R5     330       330 OHM 1/4W 1% METAL FILM RESISTOR
R6     1k         1K OHM 1/4W 1% METAL FILM RESISTOR
R8     330       330 OHM 1/4W 1% METAL FILM RESISTOR
R9     10k       10K OHM 1/4W 1% METAL FILM RESISTOR
R10    10k      10K OHM 1/4W 1% METAL FILM RESISTOR
R11    1M        1M OHM 1/4W 1% METAL FILM RESISTOR

Potentiometers
GAIN    500k-A      500K OHM LOG POTENTIOMETER
VOL      500k-A      500K OHM LOG POTENTIOMETER
TONE    5k-A          5K OHM LOG POTENTIOMETER

PCB SCHEMATIC

PCB

MODIFICATIONS

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, substitute the jumper for a diode on D4 to change to symmetric. Install the diode sockets on the opposite side of the silkscreen to leave room for the gain potentiometer.

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.

Ceramic capacitors

Ceramic 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 assemble 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.

Potentiometers

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