Mad Bean Pedals 8-Ball, Quick Start Manual

6 

The 

8-Ball

 is based on the Marshall® Blues Breaker™ pedal. It has several modifications to increase 

the range of overdrive as well as address some of the inherent brightness of the stock design. This 
should be a very easy project for all levels of builders as well as provide a solid foundation to any 
pedal board.

 
The 8-Ball includes two clipping options: the stock soft clipping and LED hard clipping. These are very 
different sounding. The soft clip is very smooth while the LED clipping is quite aggressive. The 
remaining mods are all at the component value level. The stock version has been re-voiced to a 
thicker, meaty overdrive via some cap value tweaks. The 8-Ball also has more gain on tap. Finally, 
the traditionally low output of the stock unit has been increased slightly. Note that the 8-Ball is still on 
the low side of total output so you should expect unity volume at around 1 to 2 o’clock on the Volume 
knob. 

Notes 



  D1 and D2 are shown as LEDs on the PCB (my preference for diode choice) but you can use 

other clipping diodes here such as the 1N4001. 



  You can increase the effect output further by going up to 300k on R8. This is as far as I could 

take it before making the circuit unstable. 

Voltages 

IC1

4558

1

4.66

2

4.61

3

4.2

4

0

5

4.59

6

4.6

7

4.6

8

9.2

9.42v Supply