Effect not working Guitar signal works in by pass mode (switched off) when switch on you have dry signal but no reverb. When you turn reverb knob fully clockwise the sound disappears. Possibly requires a new Op Amp
Electro-Harmonix Holy Grail Reverb Guitar Effects Pedal with Original Box
Electro-Harmonix Holy Grail Reverb Pedal
electro-harmonics Holy Grail Plus Reverb Pedal
Dunlop Herco Holy Grail Flex 75 Guitar Picks Plectrums 1,2,3,4,5,6,12,24,36
TXTone Transparent Cosmic Light Crystal Singing Holy Grail 432/440Hz With Case
Dunlop Herco HE777P Holy Grail Guitar Picks Player Pack - 6 x Plectrums
