Cornerstone Music Gear The Sparkle
Looking at the controls, there are Volume, Gain, Bass and Treble.
The Volume control acts as a master output level control.
The Bass and Treble controls manage the frequency responses of the pedal. With both set at noon, the Sparkle creates a flat frequency response, When adjusting the tone controls, the sound always stays full and well-defined without ever getting muddy or gloomy.
The 9v/18v switch allows the guitarist to choose which voltage the circuit would be supplied with, still using the same external 9v power supply. In 18v mode, the pedal offers a lot more headroom than the standard 9v, which is extremely useful for guitars with more powerful pickups.
The Sparkle requires a standard 9V DC Negative power supply only.