The Source Audio True Spring Reverb Pedal SA247 derives its reverb effects from a mechanical design developed by the Hammond Organ Company™ in the late 1930s. This design employs input and output transducers to send an instrument's dry signal through a set of spring coils, capturing the unique reverberations as the sound oscillates within the springs. Leo Fender later incorporated this design into some of his "blackface" amplifiers in the 1960s, sparking a revolution.

Short Spring Reverb: This mode emulates the distinctive twang of the 1960s "blackface" amplifiers. Our extensive research revealed a wide range of spring reverb sounds across different amps, from those with a tighter, subdued tone to others that produced a "drippier" sound with prolonged sustain and more vibrant reverb trails.

Long Spring Reverb: It generates prolonged, deep reverb decays with a pronounced "drip" and dynamic trails. The LONG Spring engine, while not as intense as the TANK Reverb engine, provides a very accurate depiction of the more animated reverb tanks found in vintage combo amplifiers.

Tank Spring Reverb (Outboard Spring): It replicates the distinctive sound of the 60s' tube-driven outboard spring tanks. The reverb tanks, like the iconic Fender 6G15™, are known for their "drippy" onset and lively trail. This classic two-spring configuration yields a resonant, delay-like effect that is synonymous with the early surf rock and spaghetti western movie soundtracks.