The Caroline Effect Pedals - "The Blues" Expensive Amplifier brings high-end amp tones to your pedalboard in a simple interface. The right knob allows you to dial in just the right amount of grit to your signal, while the left knob handles the output volume. The middle switch allows you to alternate between two different amp voicing, vintage or a higher gain modern vintage. What started out as an April Fools' joke has now been made manifest in this cheeky overdrive pedal from the crew at Caroline.