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FRACTAL PARAMETRIC OVERDRIVE

1

PROJECT NAME

FRACTAL

BASED ON

EFFECT TYPE

PROJECT SUMMARY

DOCUMENT VERSION

Pearl

®

 OD-05 Over Drive

A versatile overdrive with a single-band parametric EQ, allowing adjustable boost or cut from 100 Hz to 
4kHz.

Parametric overdrive

1.0.0 (2022-04-08)

BUILD DIFFICULTY

Intermediate

Actual size is 2.3” x 1.86” (main board) and 1.78” x 0.87” (bypass board).

Summary of Contents for FRACTAL PARAMETRIC OVERDRIVE

Page 1: ...MARY DOCUMENT VERSION Pearl OD 05 Over Drive A versatile overdrive with a single band parametric EQ allowing adjustable boost or cut from 100 Hz to 4kHz Parametric overdrive 1 0 0 2022 04 08 BUILD DIFFICULTY Intermediate Actual size is 2 3 x 1 86 main board and 1 78 x 0 87 bypass board ...

Page 2: ...clipping EQ you can get some incredible sounds out of it You can crank the mids for a cocked wah sound or tune the circuit to enhance the resonant peak of your specific guitar and amp You can even get a scooped mids sound if that s what you re after something that s pretty rare in an overdrive The updated version of the Fractal includes one new feature the fixed post clipping treble cut can be dia...

Page 3: ...ilm resistor 1 4W R11 2k2 Metal film resistor 1 4W R12 22k Metal film resistor 1 4W R13 22k Metal film resistor 1 4W R14 22k Metal film resistor 1 4W R15 22k Metal film resistor 1 4W R16 10k Metal film resistor 1 4W R17 10k Metal film resistor 1 4W R18 10k Metal film resistor 1 4W R19 1M Metal film resistor 1 4W R20 1k Metal film resistor 1 4W R21 1k Metal film resistor 1 4W R22 10k Metal film res...

Page 4: ...switching diode DO 35 D3 1N914 Fast switching diode DO 35 Q1 Q4 2N5088 BJT transistor NPN TO 92 Substitute Original uses 2SC2240 GR IC1 JRC4558D Operational amplifier DIP8 IC1 S DIP 8 socket IC socket DIP 8 IC2 JRC4558D Operational amplifier DIP8 IC2 S DIP 8 socket IC socket DIP 8 DRIVE 100kB 16mm right angle PCB mount pot FREQ 100kC dual 16mm dual gang PCB mount pot EQ 10kB 16mm right angle PCB m...

Page 5: ...me EQ settings for example using the parametric EQ to cut the midrange and then boosting the treble for a more pronounced scooped mids sound This is a new modification that has been added to the updated version of the Fractal It replaces the clipping diode switch from the legacy version which is not very useful in this particular circuit At zero it s identical to the stock circuit so there s no go...

Page 6: ...D VA VA GND GND 2k2 100kC 100kC 2k2 68n GND 4n7 22k 22k VB 22k 22k 100n 10k 10k VB 10k 470pF 100n 1M VB 47pF 1k 1k 10k 1k 220n GND 470R 15n GND VA 10k 1uF GND IN OUT RPD D1 C16 EQ GAIN 1 2 3 TONE 1 2 3 DRIVE 1 2 3 VOLUME 1 2 3 C17 C1 R1 R2 R26 R27 C14 Q1 Q2 Q3 Q4 R28 C15 R3 C2 R5 R4 R6 R7 R8 C3 R9 C4 2 3 1 IC1A 8 4 6 5 7 IC1B 2 3 1 IC2A 6 5 7 IC2B 8 4 R10 FREQUENCYA 1 2 3 1 2 3 FREQUENCYB R11 C6 C...

Page 7: ...jacks like the Switchcraft 111X If you d rather use open frame jacks please refer to the Open Frame Jack Drill Template for the top side LED hole drill size assumes the use of a 5mm LED bezel available from several parts suppliers Adjust size accordingly if using something different such as a 3mm bezel a plastic bezel or just a plain LED x 0 775 y 1 71 x 0 775 y 1 71 ø9 32 ø9 32 x 0 775 y 0 41 ø9 ...

Page 8: ...ncy potentiometer appear to be cut in half This is intentional These are called a plated half holes or castellated holes and they are used so that the PCB can lay flat across the pots instead of angling upward for the dual pot Solder it like you would if they were normal pads but bend the top pins forward slightly so they make contact with the edge of the pads 125B ...

Page 9: ...FRACTAL PARAMETRIC OVERDRIVE 9 WIRING DIAGRAM 125B IN V GND N C N C OUT PCB IN GND V V JACK GND JACK OUT IN GND GND PCB OUT ...

Page 10: ...nly as suggestions based on the experience and opinions of others Projects may be used for commercial endeavors in any quantity unless specifically noted No attribution is necessary though a link back is always greatly appreciated The only usage restrictions are that 1 you cannot resell the PCB as part of a kit without prior arrangement and 2 you cannot goop the circuit scratch off the screenprint...

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