Rocktron Reaction HUSH - Manual (Page 13)

The Variable Integrated Release (V.I.R.) technol-
ogy contained in each HUSH circuit automatically
adjusts the release rate of the expander based on
the dynamic decay rate of the incoming signal. If
the input signal stops suddenly, downward expan-
sion will occur rapidly (similar to a gate). If the
input signal decays slowly, expansion will occur
slowly without disrupting the dynamic decay of the
input signal.
The THRESHOLD control should be adjusted by
listening to the noise floor while not playing. Turn
the THRESHOLD control clockwise to the point
where the noise floor becomes inaudible. Turning
too far past this point will cause the downward ex-
pander to attenuate the output level too quickly and
not allow the signal to decay as long as it should.