The Blood Donor fuzz pedal from Catalinbread is a revamped, fine-tuned version of the venerable Katzenkonig with a slew of changes that truly unlock the circuit’s potential. A carefully selected transistor set has been added, which pushes the boundaries of saturation and gain to their electrical limits, giving the pedal a little more fur and bite. The noise floor has been trimmed while widening the utility of all controls, giving an increased range of input sensitivity that mimics the volume knob on your guitar. The Catalinbread Blood Donor can be powered with a standard 9V battery, or a center-negative, regulated 9V DC external power supply.