Lexicon PCM 80 - Manual (Page 65)

3-7
The Algorithms and Their Parameters
Infinite Infinite is acoustically similar to the Chamber algorithm, with the addition of an
Infinite parameter. When this parameter is turned on, the input to the reverberator
ramps off. (Note that this still allows the Reverb Shell to be utilized.) With Infinite
on, the reverb tail remains constant, creating strange and useful reverb effects.
When Infinite is switched off, input to the reverberator is restored, and the current
running reverb time is utilized.