This is a bit of a unicorn nowadays ! An original large format Holy Grail Reverb!

It comes with a power supply adaptor so you can use a standard 9v cord to power it. Note that you have to use an isolated brick style power supply or just have it running from its own plug (like an ispot or some other individual 9v power supply).

In excellent condition, especially for its age!

“Unveiling the Electro-Harmonix Holy Grail, a true classic in the realm of reverb effect pedals. This coveted piece of gear, renowned for its customizable reverb settings, offers a universal solution for guitarists in need of that perfect echo. With its singular knob control and a choice of "spring," "hall," and "flerb" modes, it allows for a seamless blend between simplicity and versatility. Experience the timeless tone of this pedal that's been a favorite among musicians, maintaining its popularity over the years despite its larger enclosure.

Key Features:

• Single knob control for easy adjustment of reverb intensity
• Three selectable reverb modes: "spring," "hall," and "flerb"
• Larger enclosure, maintaining the classic design of earlier versions”