“Jeff Tweedy’s acoustic pedal board just consists of an Electro Harmonix Holy Grail Reverb, a [volume pedal](http://equipboard.com/items/ernie-ball-volume-pedal), and the ubiquitous [Boss TU-2](http://equipboard.com/items/boss-tu-2-chromatic-tuner) tuner.” - [*Austin City Limits*](http://acltv.com/tag/gear/).more
The Holy Grail features three types of reverb: hall, spring, and flerb, which is a flange+reverb setting. Each setting sounds great and fills out the tone of whatever one is playing very well. It can be used for ambient swells or delay work, or to round out a driven sound. The amount of reverb is modifiable, and the pedal could not be easier to use. I recommend this pedal very much for the price for those looking for a professional sound.