Eternal Spring is a low-pass filter with personality. Depending on its drive and resonance settings, the circuit can add a little bit of saturation, a good amount of dirt or heavy distortion to incoming audio material. Occasionally, users will feel reminiscent of a wavefolder. The cutoff potentiometer means business. The resonance ranges up to beefy self-oscillation. However, thanks to the gain stages acting like a natural limiter, the circuit won’t squeal all too loud. – Therefore, musicians can boldly reach for all controls. A FM input allows wild modulations in the audio range. Temperature compensation was deliberately omitted in order to give the Eternal Spring a more lively character.

The module comes equipped with an AC-coupled audio input. The following drive circuit is able to boost incoming signals considerably. Its results range from light saturation to harsh distortion. The filter section features cutoff and resonance potentiometers. In addition, there is a CV input with attenuator and a phase inverted FM input. Drive and resonance parameters influence each other. The lack of temperature compensation causes musical instabilities.