125B · 3 knobs
PhobosGermanium Fuzz
Based on the Tone Bender Mk III· 1 other board clones it
- Category
- Fuzz· Germanium Fuzz
- Controls
- Fuzz · Tone · Volume
- Difficulty
- Easy
- Price
- $12.50in stock
From the vendor
A reproduction of the third version of the Tone Bender germanium fuzz sold by Macaris in London in the late 1960s.
The Phobos Germanium Fuzz is a clone of the Colorsound / Sola Sound Tone Bender Mk III. While the first version was essentially the same topology as a Fuzz Face, and the second version added a gain stage in front, this third version from 1967-1968 was a completely different circuit, using a Darlington-pair transistor configuration to drive a third transistor, followed by a tone control which the earlier versions were missing.
While the Mk. III Tone Bender was itself a variation of the Baldwin-Burns Buzzaround, it had a few variants of its own, both official and unofficial. The Vox Tone Bender was a licensed variant with a few parts substitutions. The Park Fuzz Sound by Park Amplification (Jim Marshall’s side-brand) was a contemporary clone. The Elka Dizzytone and the Prescription Electronics Yard Box were two others. Aside from the Buzzaround, all of the rest of these variations can be build on this PCB.
A note about the name: the original Colorsound / Sola Sound unit was not called the “Mark III”, but the Vox-licensed version was. As a result, this circuit is commonly called both the “Mark III” and the “three-knob” Tone Bender. This project will refer to it as the Mk III to differentiate it from the Mk II, which is available as another project called the Deimos.
The Phobos project has a voltage inverter which allows you to power the effect with a standard center-negative adapter while maintaining the positive-ground operation of the original. The PCB also includes biasing trim pots so you can dial in a perfect bias without having to swap out resistors.
Schematic
The schematic is in the vendor's build document, page 7. Open the build document. No KiCad fragment has been drawn for this circuit yet.
Parts list 46 rows
Report a wrong parse| Ref | Value | Normalized | Type | Notes |
|---|---|---|---|---|
| Resistors 12 | ||||
| R1 | 47k | 47k | Metal film resistor, 1/4W | |
| R2 | 220k | 220k | Metal film resistor, 1/4W | |
| R3 | 1k | 1k | Metal film resistor, 1/4W | |
| R4 | 10k | 10k | Metal film resistor, 1/4W | |
| R5 | 3k3 | 3.3k | Metal film resistor, 1/4W | |
| R6 | 18k | 18k | Metal film resistor, 1/4W | |
| R7 | 1k | 1k | Metal film resistor, 1/4W | |
| R8 | 10k | 10k | Metal film resistor, 1/4W | |
| R9 | 10k | 10k | Metal film resistor, 1/4W | |
| R10 | 220k | 220k | Metal film resistor, 1/4W | |
| RPD | 1M | 1M | Metal film resistor, 1/4W | Input pulldown resistor. Can be as low as 1M. |
| LEDR | 10k | 10k | Metal film resistor, 1/4W | LED current-limiting resistor. Adjust value to change LED brightness. |
| Capacitors 11 | ||||
| C1 | 100n | 100n | Film capacitor, 7.2 x 2.5mm | |
| C2 | 220pF | 220p | MLCC capacitor, NP0/C0G | |
| C3 | 220n | 220n | Film capacitor, 7.2 x 2.5mm | |
| C4 | 10uF | 10u | Electrolytic capacitor, 5mm | |
| C5 | 100n | 100n | Film capacitor, 7.2 x 2.5mm | |
| C6 | 2n2 | 2.2n | Film capacitor, 7.2 x 2.5mm | |
| C7 | 100uF | 100u | Electrolytic capacitor, 6.3mm | |
| C8 | 10uF | 10u | Electrolytic capacitor, 5mm | |
| C9 | 47uF | 47u | Electrolytic capacitor, 5mm | |
| C10 | 470n | 470n | MLCC capacitor, X7R | |
| C11 | 100n | 100n | MLCC capacitor, X7R | |
| Diodes 3 | ||||
| Z1 | 1N4742A | 1N4742A | Zener diode, 12V, DO-41 | |
| D1 | 1N5817 | 1N5817 | Schottky diode, DO-41 | |
| D2 | Germanium | GERMANIUM | Germanium diode, DO-07 | Original uses 1N270, but part number isn’t important. Just use any NOS germanium diode. |
| Transistors 4 | ||||
| Q1 | Germanium | GERMANIUM | Germanium transistor, PNP | Recommended to buy a selected Tone Bender Mk III set. See build notes. |
| Q2 | Germanium | GERMANIUM | Germanium transistor, PNP | Recommended to buy a selected Tone Bender Mk III set. See build notes. |
| Q3 | Germanium | GERMANIUM | Germanium transistor, PNP | Recommended to buy a selected Tone Bender Mk III set. See build notes. |
| Q3B | 50k trimmer | 50K TRIMMER | Trimmer, 10%, 1/4" | Bias trimmer for Q3. See build notes. |
| ICs 1 | ||||
| IC1 | TC1044SCPA Volt | TC1044SCPA VOLT | age inverter, DIP8 | |
| Potentiometers 3 | ||||
| FUZZ | 100kB | B100k | 16mm right-angle PCB mount pot | |
| TONE | 100kB | B100k | 16mm right-angle PCB mount pot | |
| LEVEL | 100kA | A100k | 16mm right-angle PCB mount pot | |
| Trimmers 1 | ||||
| Q1-2B | 50k | 50k | Trimmer, 10%, 1/4" | Bias trimmer for Q1 and Q2. See build notes. |
| Switches 1 | ||||
| FSW | 3PDT | 3PDT | Stomp switch, 3PDT | |
| LEDs 1 | ||||
| LED | 5mm | 5MM | LED, 5mm, red diffused | |
| Jacks & sockets 7 | ||||
| Q1-S | TO-5 socket | TO-5 SOCKET | Transistor socket, TO-5 | |
| Q2-S | TO-5 socket | TO-5 SOCKET | Transistor socket, TO-5 | |
| Q3-S | TO-5 socket | TO-5 SOCKET | Transistor socket, TO-5 | |
| IC1-S | DIP-8 socket | DIP-8 SOCKET | IC socket, DIP-8 | |
| IN | 1/4" stereo | 1/4" STEREO | 1/4" phone jack, closed frame | Switchcraft 112BX or equivalent. |
| OUT | 1/4" mono | 1/4" MONO | 1/4" phone jack, closed frame | Switchcraft 111X or equivalent. |
| DC | 2.1mm | 2.1MM | DC jack, 2.1mm panel mount | Mouser 163-4302-E or equivalent. |
| Hardware 2 | ||||
| BATT | Battery snap | BATTERY SNAP | 9V battery snap | Optional. Use the soft plastic type—the hard-shell type will not fit. |
| ENC | 125B | 125B | Enclosure, die-cast aluminum | Can also use a Hammond 1590N1. |
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