In Stock. 45 Day Lowest Price - 100% Satisfaction Guarantee. Now you can have the warmth, the depth, the richness of a 50's era spring reverb - and use it with any amp, anywhere, any time. The SPRING KING sounds like a real spring reverb from the 50's because, well, it is! Danelectro started with an authentic spring reverb tank and fussed and fiddled and tweaked until the sound was "just so." The result is a rich, thick spring reverb delivering "just the right tone and warmth."