Source Audio SA247 True Spring Reverb is the classic natural spring reverb along with a pulsing tremolo. Source Audio does not rely on the standard reverb effect processors found in many modern reverb pedals; we meticulously craft each of our proprietary effect engines and load them into a high-powered 56-bit Sigma DSP. Our two-man engineering team, Bob Chidlaw and Jesse Remignanti, dedicated years of collective work hours to capturing every nuance and idiosyncrasy of the spring reverb and tremolo effects of some of the most iconic guitar amplifiers and outboard equipment in the music gear industry. The result is indisputable sound quality with magnificent tonal depth and precision.

The True Spring reverb effects are based on a mechanical design created by Hammond Organ Company ™ in the late 1930s. This austere design uses a pair of input and output transducers to inject the dry signal of an instrument into a real set of spring coils and capture the very distinct reverberations as the sound bounces back and forth inside the springs. Of course, Leo Fender adopted this design in the 1960s with some of his "blackface" amplifiers, and a revolution was born.

• Short Spring Reverb: Modeled after the unmistakable sound of 1960s "blackface" amplifiers. After extensive research, we found a huge diversity in the spring reverb sounds of a variety of amplifiers. Some offered a tighter and less lively tone, while others sounded more "drip-y," with longer sustain and livelier reverb trails. The SHORT Spring reverb engine offers a tight sound with a fast decay and smooth trails.
• Long Spring Reverb: Produces long and deep reverb decays with a notable "drip" and very lively trails. The LONG Spring engine is not as spectacular as the TANK Reverb engine, but it offers an extremely authentic representation of some of the liveliest reverb tanks found in classic combo amplifiers.
• Tank Spring Reverb (external spring): captures the unmistakable effect of 1960s tube-driven external spring tanks. The sound of reverb tanks like the classic Fender 6G15 ™ is characterized by its "drip-y" attack and lively trail. This original two-spring design produces a bouncing delay sound, inseparable from the early days of surf rock and spaghetti western soundtracks.