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Sungrazer
Based on the Monolith Oracle Fuzz· 4 other boards clone it
Want a PCB? Naegele Audio laid out a PCB for this circuit and sells boards, as well as relay bypass and I/O boards: message PedalBuilder on the PedalPCB forum.
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- Fuzz
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From the vendor
Here's my take on the Monolith Oracle. The original is described as being a modified Tone Bender Mk. I.5, although it's biased like a Fuzz Face. Either way, it's the familiar feedback amplifier topology followed by a Big Muff-style tone control. The schematic is at the bottom of the post. The stock Monolith Oracle uses a switch to change the resistor in the low pass filter side of the tone (Color) control between 12k and 100k. I replaced the switch with a B100k pot (Voice) and a 10k resistor, which lets you get either of the switch values, as well as any in between values. I also added an off board resistor between lug 1 of the Density control and ground so that the pedal doesn't mute when the Density control is turned all the way down. The original purportedly used high gain OC76 transistors, with hFE around 100 for Q1 and 300 for Q2. I used some higher gain Soviet transistors in mine. Q1 is a GT115G (hFE 116, leakage 115µA) and Q2 is a GT115D (hFE 292, leakage 109µA). With VCC = -9.11v, the Q2 collector voltage is 4.68v. It makes for an interesting comparison to the Analogman Peppermint Fuzz, another Fuzz Face variant with higher gain germanium transistors. While the Peppermint is voiced for 60's psychedelic buzz, the Oracle is voiced for sludgy desert/stoner/doom tones, likely due to the Oracle's larger Q2 emitter bypass capacitor and the treble cut from the tone stack. If you have a high gain germanium transistor sitting around and want a heavy fuzz face, the Oracle is worth your consideration. OUTSIDE <a href="https://forum.pedalpcb.com/attachments/img_5175-png.104500/" target="_blank"> <img src="data:image/svg+xml;charset=utf-8,%3Csvg xmlns%3D'http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg' width='1400' height='1867' viewBox%3D'0 0 1400 1867'%2F%3E" data-src="https://pedalpcb-forum.nyc3.digitaloceanspaces.com/data/attachments/104/104519-ccfeaccddf66a0deaeb3993342edbc80.jpg?hash=iIfkJz6Bd3" class="bbImage lazyload" style="" alt="IMG_5175.png" title="IMG_5175.png" width="150" height="201" /> <img src="https://pedalpcb-forum.nyc3.digitaloceanspaces.com/data/attachments/104/104519-ccfeaccddf66a0deaeb3993342edbc80.jpg?hash=iIfkJz6Bd3" class="bbImage " style="" alt="IMG_5175.png" title="IMG_5175.png" width="150" height="201" /> INSIDE <a href="https://forum.pedalpcb.com/attachments/img_5178-png.104501/" target="_blank"> <img src="data:image/svg+xml;charset=utf-8,%3Csvg xmlns%3D'http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg' width='1400' height='1868' viewBox%3D'0 0 1400 1868'%2F%3E" data-src="https://pedalpcb-forum.nyc3.digitaloceanspaces.com/data/attachments/104/104520-68ccf97d71db6346c9b371febdf929f8.jpg?hash=EIe4brjqq_" class="bbImage lazyload" style="" alt="IMG_5178.png" title="IMG_5178.png" width="150" height="201" /> <img src="https://pedalpcb-forum.nyc3.digitaloceanspaces.com/data/attachments/104/104520-68ccf97d71db6346c9b371febdf929f8.jpg?hash=EIe4brjqq_" class="bbImage " style="" alt="IMG_5178.png" title="IMG_5178.png" width="150" height="201" /> SCHEMATIC
Schematic
The schematic is in the post. Open it at Naegele Audio. No KiCad fragment has been drawn for this circuit yet.
Parts list 27 rows
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Check before you build · 1 value the reader of this schematic was not sure of
- R101: LED resistor drawn as 'CLR' with no value
| Ref | Value | Normalized | Type | Notes |
|---|---|---|---|---|
| Resistors 10 | ||||
| R1 | 470k | 470k | read from the schematic by eye | |
| R2 | 33k | 33k | read from the schematic by eye | |
| R3 | 100k | 100k | read from the schematic by eye | |
| R4 | 7k5 | 7.5k | read from the schematic by eye | |
| R5 | 3k | 3k | read from the schematic by eye | |
| R6 | 820R | 820 | read from the schematic by eye | |
| R7 | 10k | 10k | in series with Voice; read from the schematic by eye | |
| R8 | 68k | 68k | read from the schematic by eye | |
| R9 | 3k9 | 3.9k | between Density lug 1 and ground; read from the schematic by eye | |
| R101 | ? | ? | LED current limiting resistor, drawn as CLR; read from the schematic by eye | |
| Capacitors 9 | ||||
| C1 | 53p | 53p | read from the schematic by eye | |
| C2 | 56n | 56n | read from the schematic by eye | |
| C3 | 100µ | 100u | read from the schematic by eye | |
| C4 | 1µ | 1u | read from the schematic by eye | |
| C5 | 6n8 | 6.8n | read from the schematic by eye | |
| C6 | 1µ | 1u | read from the schematic by eye | |
| C101 | 100µ | 100u | supply filter; read from the schematic by eye | |
| C102 | 10µ | 10u | LT1054 charge pump; read from the schematic by eye | |
| C103 | 22µ | 22u | LT1054 output; read from the schematic by eye | |
| Transistors 2 | ||||
| Q1 | GT115G | GT115G | germanium PNP, hFE 116, leakage 115µA; read from the schematic by eye | |
| Q2 | GT115D | GT115D | germanium PNP, hFE 292, leakage 109µA; read from the schematic by eye | |
| ICs 1 | ||||
| IC1 | LT1054CP | LT1054CP | voltage inverter; read from the schematic by eye | |
| Potentiometers 4 | ||||
| Density | C1M | C1M | Potentiometer | read from the schematic by eye |
| Voice | B100k | B100k | Potentiometer | read from the schematic by eye |
| Color | B250k | B250k | Potentiometer | read from the schematic by eye |
| Volume | A500k | A500k | Potentiometer | read from the schematic by eye |
| LEDs 1 | ||||
| LED | LED | LED | status LED; read from the schematic by eye | |
Other boards based on the Monolith Oracle Fuzz
- Monolith Oracle Fuzz Dirtbox Layouts
- Monolith Oracle Fuzz Effects Layouts (blog)
- Monolith Fuzz Oracle Tagboard Effects
- Monolith Oracle turretboard.org