The Holy Grail Nano from Electro-Harmonix is a compact digital reverb pedal that features three different reverb algorithms: Spring, Hall, and Flerb. The algorithms were designed and tailored for the electric guitar, but work equally well with most instruments and voices. A three-position switch lets you choose the reverb style and a Reverb knob acts as a wet/dry control. The unit is enclosed in a compact, rugged die-cast chassis, and comes with a US9.6VDC-200BI power supply.

The Spring algorithm is a re-creation of the classic spring reverbs that are found in many guitar amplifiers. The Hall algorithm simulates the reverberations heard in large spaces such as concert halls and cathedrals. The Flerb algorithm combines flanging with spatial reverb to create an ethereal sound. True bypass switching ensures your tone won't be affected when the pedal is bypassed.