John Frusciante started using this effect pedal around the time of the ‘By the Way’ release, circa 2002. It was seen regularly on his pedalboard during the album tour, which means that the same unit was also likely used during the studio sessions. The pedal was also used extensively during the ‘Stadium Arcadium’ era.
Holy Grail and the Clean Sound
Apparently, the way John had it set up most of the time was that it stud right between his Boss CE-1 Chorus and his Marshall Silver Jubilee. To remind you, in case you haven’t read about the CE-1 – he used the Boss to basically split his signal between a Marshall Major (crunch) and Marshall Silver Jubilee (clean sound). Based on this, the Electro-Harmonix Holy Grail Reverb played a major part in how John achieved his clean sound – or at least it did when it was used in this fashion.
Three reverb options are available via the slide switch: Spring, Hall and Flerb. The first, Spring, is modeled on the spring reverbs found in typical guitar combos, right down to the rhythmic flutter, though there's no 'sproing' when you kick the unit! As with the real thing, the only variable is how much you dial in, but I thought it was actually pretty good. Next is 'Hall', and though it may be a little on the generous side for some types of music, it's absolutely perfect for doing cover versions of Peter Green's 'Albatross' or that type of blues that sounds as though it was recorded at a large venue when nobody turned up! As for Flerb, the manual (actually a piece of blue paper) says that it is 'a beautiful reverb like nothing you have heard before and may help you to play your instrument in new ways'. To me, though, it sounds like a flanged reverb, a bit like the guitar effect on the intro to 'Shine On' by Pink Floyd.