THE ICE 9 OverDrive PEDAL

There is the interesting part of the name of VOX PEDAL OverDrive is also used by the master Joe Satriani, thats name is THE ICE 9 OverDrive PEDAL, borrowed from the title of one of Satriani's popular song on his smash 1987 album Surfing with the Alien.

The Ice 9 is voiced with both a custom Tone control and an extra Bass response knob. Although they both work together, each affects the tone at a different point in the signal chain. The Bass control adds extra bottom to the sound before it enters the drive stage, delivering dynamic low-end response. The Tone control shapes the sound as it exits the drive stage, offering even more sonic flexibility. Satriani worked with VOX engineers to contour the tone controls to focus on the most desirable frequency ranges of classic overdrives, while eliminating unusable extreme settings of some of those units.

Source : satriani.com