The Black Spring Reverb from Erica Synths is an analog spring reverb effect that uses mechanical means to create its effects. The spring reverb is a classic effect from the first half of the 19th century. Its charismatic, clangorous but also dense sound delights enthusiasts and users of this spring-based room simulation to this day. Thanks to the Vactrol-based compressor, the sound is more controllable. The open feedback loop is not only adjustable in intensity, a whole seven variants provide impressive spring reverb variations. In addition to the internal reverb tank, a toggle switch can be used to switch to the external one, or both can be activated.