905 spring reverb

moog905 · processors · schema v1

905 Spring Reverberation (moogafakkin System 55 clone — categorized under Ports -> moogafakkin). The classic spring-tank reverb: metallic, dispersive, with the characteristic "boing"/chirp on transients. In-house dispersive-allpass spring model — a cascaded all-pass chain (the dispersion) feeding a modulated feedback delay with damping. MIX blends dry/wet, DECAY sets the tail length, SIZE the spring length/character. Own-code (clean-room; feedback-clamped for stability). Beige moogafakkin faceplate (the intrinsic always-on look shared by the moogafakkin module family).

A recreation of the Moog 905 spring reverberation tank — the classic metallic, splashy spring reverb with the characteristic boing and chirp on transients. It is an in-house dispersive-allpass model (own code, not a physical PDE or a port of any reverb): a cascade of Schroeder all-pass sections gives the frequency-dependent group delay that IS the spring's dispersion and chirp, feeding a modulated feedback delay line with in-loop damping for the tail. The MIX knob blends the dry input with the spring's wet output, DECAY sets how long the tail rings, and SIZE sets the spring length — short and tight, or long and boingy. Patch a signal in and dial MIX up for a splash of vintage spring on drums, guitar, or synth.

the faceplate

1 inputs · 1 outputs · 3 params

about this module

Hover a control, or open the patch panel and hover a jack.

inputs

id	cable	what it does
`audio`	audio	The dry signal to reverberate — the audio fed into the spring tank. audio signal

outputs

id	cable	what it does
`audio`	audio	The dry/wet mix: the dry input blended with the spring-reverb wet tail, ratio set by the MIX knob. audio signal

params

id	label	range	default	curve
`mix`	Mix	0..1	0.35	linear
`decay`	Decay	0..1	0.6	linear
`size`	Size	0..1	0.5	linear

controls

control	what it does
Decay	Tail length / feedback — how long the spring rings before fading. Low gives a short metallic splash; high gives a long, sustained wash. Defaults to 0.6.
Mix	Dry↔wet blend — 0 is fully dry (the spring is silent), 1 is fully wet (only the reverberated tail). Lower for a subtle ambience, higher for a drenched, surfy spring. Defaults to 0.35.
Size	Spring length / dispersion — how much chirp and boing the tank has. Small is a tight, bright spring; large stretches the dispersion for the long, wobbly, more dramatic spring character. Defaults to 0.5.

source

moog905.ts on GitHub.