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PHOBOS GERMANIUM FUZZ

1

PROJECT NAME

PHOBOS

BASED ON

EFFECT TYPE

PROJECT SUMMARY

DOCUMENT VERSION

Tone Bender Mk. III (3-knob)

A reproduction of the third version of the Tone Bender germanium fuzz sold by Macaris in London in the 
late 1960s.

Germanium fuzz

1.0.1 (2022-07-01)

BUILD DIFFICULTY

This documentation is for the 

kit

 version of the project. If you purchased the PCB by itself, please 

use the 

PCB-only version

 of the documentation instead. The circuit is the same, but the instructions 

are completely different due to the specialized parts and assembly methods used in the kit.

IMPORTANT NOTE

Intermediate

LEVEL

GERMANIUM FUZZ

FUZZ

TONE

9V

PHOBOS

Summary of Contents for PHOBOS

Page 1: ...the late 1960s Germanium fuzz 1 0 1 2022 07 01 BUILD DIFFICULTY This documentation is for the kit version of the project If you purchased the PCB by itself please use the PCB only version of the docu...

Page 2: ...rs Non Polarized 15 Wire Headers 16 Capacitors Polarized 17 Germanium Transistors Introduction 18 Germanium Transistors Q1 and Q2 19 Germanium Transistors Q3 20 Footswitch PCB 21 Input Output PCB 22 E...

Page 3: ...to learn a few things along the way This will take time Plan on about two hours start to finish It may take even longer if it s your first time building Don t rush it If you find yourself getting frus...

Page 4: ...Film Capacitors NAME QTY 2n2 0 0022 1 100n 0 1 2 220n 0 22 1 Electrolytic Capacitors NAME QTY 10uF 2 47uF 1 100uF 1 MLCC Capacitors NAME QTY 220pF marked 221 1 100n marked 104 1 470n marked 474 1 Diod...

Page 5: ...C jack 1 Input output jack 2 Mounting nut jack 0 54 4 Outer washer jack 0 6 2 Lock washer jack 0 5 thin 2 Enclosure 1 Enclosure screws 4 PCB main circuit 1 PCB footswitch 1 PCB input output DC 1 Switc...

Page 6: ...solder NEEDLE NOSE PLIERS These are used for bending leads on components and other general uses Use the smaller type with a tip that s approximately 0 05 1 25mm wide FLAT SCREWDRIVER SMALL This is us...

Page 7: ...LED BEZEL WIRE ASSEMBLY ELECTROLYTIC CAPACITOR GERMANIUM DIODE OP AMP IC TANTALUM CAPACITOR SCHOTTKY DIODE IC SOCKET TRANSFORMER MLCC RECTIFIER DIODE TRANSISTOR OR JFET Not polarized Color may vary by...

Page 8: ...SWITCH POTENTIOMETER SINGLE FOOTSWITCH POTENTIOMETER DUAL MOUNTING NUT MOUNTING NUT MOUNTING NUT MOUNTING NUT DRESS NUT OUTER WASHER DRESS NUT OUTER WASHER KNOB LOCK WASHER LOCK WASHER LOCK WASHER LOC...

Page 9: ...PCBs shown to the right The general principle for PCB population is that you want to work in layers from shortest components i e lowest profile to tallest so that when the PCB is upside down everythi...

Page 10: ...the components held in place while you solder You ll use this same technique for most of the other components as well If it gets too crowded just flip the board and solder everything you ve done so fa...

Page 11: ...the other components Make sure to observe the following precautions when working with them To prevent stress on the glass body of the diode when bending the leads use needle nose pliers or tweezers to...

Page 12: ...citors This information is just listed here for reference The legs of the IC are bent outward slightly during manufacturing so they ll need to be bent back inward before they can be inserted into the...

Page 13: ...o either one can be used in either position The trimmers can be soldered like normal components by bending the legs outward as shown These trimmers are used to bias the germanium transistors We will a...

Page 14: ...d will work in any direction To keep things neat though it s best to put them all facing the same way so the values can easily be read Note C6 box film capacitor may be either blue or red The blue one...

Page 15: ...tors as shown above These have a polarity pin so as long as they are pressed all the way down there s only one possible way to install them They do fit pretty tightly in the holes though so press firm...

Page 16: ...l only work in one direction so note the vertical mark that indicates the negative side The longer leg is positive and fits in the square pad At this point we only have the transistors left to do so n...

Page 17: ...and only one at a time to avoid inadvertently mixing them up Q1 and Q2 are not always visually distinguishable from each other and outside of the bags there may be no way to tell which is which The p...

Page 18: ...the previous page it s important to leave Q2 in its bag until Q1 has been soldered so they don t get mixed up Insert it into the pads on the PCB being mindful of the orientation either the V pattern...

Page 19: ...The third diagram shows a side view Make sure there s some clearance above the resistors The resistors are electrically insulated so it s not going to cause any problems if the metal body of the tran...

Page 20: ...later step PARTS 3 strand wire assembly 2 4 strand wire assembly STEP 3 Then solder the wires from the top This is the trickiest part of the whole build You want to solder the pads without touching t...

Page 21: ...is in place and you don t want the pins to short against anything on accident Next we ll hook up the 9V battery connector This is optional Not everyone uses batteries But if you do this pedal should...

Page 22: ...unting nut and is for aesthetic purposes only Wrap a rubber band around it to use as a grip when tightening Do not use metal tools on it or you run the risk of scratching or denting it You ll need to...

Page 23: ...e main PCB on top of the potentiometers and toggle switches as in the diagram to the left You may need to adjust the position of the potentiometers and toggle slightly if they are not aligned straight...

Page 24: ...f the enclosure as shown Note the use of two mounting nuts on each of the jacks one inside and one outside The inner nut acts as a spacer to set the DC jack flush with the outside of the enclosure The...

Page 25: ...itive or negative depending on which lead is touching which pad Next touch the multimeter leads to the pads marked Q3 TEST This is equivalent to the collector of Q3 Rotate the trimmer until you read 2...

Page 26: ...ng a small flat head screwdriver no more than 0 1 2 5mm in diameter tighten the set screw until it presses against the shaft of the potentiometer and holds the knob in place Don t over tighten or you...

Page 27: ...R_GND 47uF VA PWR_GND GND Ge 1k VA Ge 18k 1k 10k 2n2 GND GND 10kB 10kB 10k 470n 100n GND 220k 220pF VA 3k3 10uF GND GND Ge GND VA 100kB GND 100n GND 220k IN OUT RPD D1 C7 LEVEL 1 2 3 FUZZ 1 2 3 C11 R1...

Page 28: ...0022 PART VALUE R5 3k3 R6 18k or 18 2k R7 1k R8 10k PART VALUE R9 10k R10 220k RPD 2M2 LEDR 4k7 PART VALUE C7 100uF electro C8 10uF electro C9 47uF electro C10 470n MLCC C11 100n MLCC Resistors Capac...

Page 29: ...circuit The easiest spot is inside a tapped screw hole in one of the corners of the enclosure This way the probe stays in place without needing to use alligator clips The circuit must of course be ful...

Page 30: ...site There is no guarantee that we will be able to join the discussion and help solve your problem but this improves the chances It benefits the whole community if the troubleshooting process is publi...

Page 31: ...trademark holders These kits are intended to be built by the customer Aion FX is not responsible for language that may be used by the customer in the marketing or resale of the finished product All co...

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