125B · 4 knobs
TethysGermanium Fuzz
Based on the Baldwin-Burns Buzzaround
- Category
- Fuzz· Germanium fuzz
- Controls
- Sustain · Tone · Balance · Volume
- Difficulty
- Easy
- Price
- $12.50in stock
From the vendor
An early version of the Tone Bender Mk. III with a completely different voicing and transistor bias control, sold by the Baldwin-Burns company in London.
The Tethys Germanium Fuzz is an adaptation of the Baldwin-Burns Buzzaround, a germanium transistor fuzz first sold in 1966 and best known as Robert Fripp’s fuzz of choice in the late 1960s.
The Buzzaround is very similar to the third version of the Tone Bender (3-knob, often called the Mk. 3) and for that reason it’s often believed to have been a clone. However, the Buzzaround actually came earlier and the Mk. 3 was the derivative circuit, not releasing until 1967.
Despite persistent rumors that the Buzzaround was designed Gary Hurst (the inventor of the first two versions of the Tone Bender), it was discovered more recently that it was probably copied from an earlier effect called the Harmonic Generator from G. P. Electronics in Devon. No known examples of the Harmonic Generator survive to know for certain, but the control layout is the same and the advertising copy makes the similarities very clear.
The major difference between the Buzzaround and Tone Bender is the volume control, called Balance. This is actually a bias control on the third transistor and changes the tone throughout the travel, not just the signal level. Because of this, builders will generally add a true volume control in DIY Buzzaround implementations, which we’ve included here. You can use either of the controls or both in combination.
The two other notable differences from the Tone Bender Mk3 are in the gain and tone controls. The Buzzaround’s gain control is set up as a voltage divider (inter-stage volume control) rather than a variable resistor as in the Tone Bender, and the tone control is also voiced differently. These changes along with the Balance control make it a very different pedal, even though at first glance the schematics appear almost identical.
Schematic
The schematic is in the vendor's build document, page 6. Open the build document. No KiCad fragment has been drawn for this circuit yet.
Parts list 44 rows
Report a wrong parse| Ref | Value | Normalized | Type | Notes |
|---|---|---|---|---|
| Resistors 10 | ||||
| R1 | 100k | 100k | Metal film resistor, 1/4W | |
| R2 | 470k | 470k | 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 | 15k | 15k | Metal film resistor, 1/4W | |
| R7 | 27k | 27k | Metal film resistor, 1/4W | |
| R8 | 10k | 10k | Metal film resistor, 1/4W | |
| RPD | 1M | 1M | Metal film resistor, 1/4W | Input pulldown resistor. |
| 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 | 100pF | 100p | MLCC capacitor, NP0/C0G | |
| C3 | 4.7uF | 4.7u | Electrolytic capacitor, 4mm | |
| C4 | 4.7uF | 4.7u | Electrolytic capacitor, 4mm | |
| C5 | 100n | 100n | Film capacitor, 7.2 x 2.5mm | |
| C6 | 1n | 1n | 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 3 | ||||
| Q1 | Germanium | GERMANIUM | Germanium transistor, PNP | Recommended to buy a selected set. See build notes. |
| Q2 | Germanium | GERMANIUM | Germanium transistor, PNP | Recommended to buy a selected set. See build notes. |
| Q3 | Germanium | GERMANIUM | Germanium transistor, PNP | Recommended to buy a selected set. See build notes. |
| ICs 1 | ||||
| IC1 | TC1044SCPA Volt | TC1044SCPA VOLT | age inverter, DIP8 | |
| Potentiometers 4 | ||||
| SUSTAIN | 100kB | B100k | 16mm right-angle PCB mount pot | |
| TIMBRE | 100kB | B100k | 16mm right-angle PCB mount pot | |
| BALANCE | 10kB | B10k | 16mm right-angle PCB mount pot | |
| VOLUME | 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. |