Rocktron Piranha - Manual (Page 14)

11
E. Setting the
HUSH ®
Threshold
HUSH is Hush Systems’ patented single-ended noise reduction system. The low level expander of the HUSH system
operates like an electronic volume control. HUSH utilizes a voltage-controlled amplifier (VCA) circuit which can control
the gain between the input and the output from unity to 30, 40 or even 50dB of gain reduction. When the input signal is
above the user preset threshold point, the VCA circuit remains at unity gain. (This means that the amplitude of the output
signal will be equal to that of the input signal.) As the input signal level drops below the user preset threshold point,
downward expansion begins. At this point the expander acts like an electronic volume control and gradually begins to
decrease the output signal level relative to the input signal level. As the input signal drops further below the threshold
point, downward expansion increases. A drop in the input level by 20dB would cause the output level to drop approxi-
mately 40dB (i.e., 20dB of gain reduction). In the absence of any input signal, the expander will reduce the gain so that
the noise floor becomes inaudible.
The HUSH included in the Piranha also incorporates patented V.I.R. (Variable Integrated Release) circuitry, which
intelligently tracks the guitar signal. Long, sustained notes are allowed to decay naturally without being cut off, while
quick, muted notes release quickly without a trail of noise following. The HUSH threshold is adjustable via the UP and
DOWN buttons, and is programmable for each preset (press STORE twice to save the selected threshold). When set at its
lowest threshold setting (-70), the HUSH circuit is not active.
ΠPress the HUSH button to display the current HUSH setting.
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 Use the UP and DOWN buttons to change the current HUSH threshold value.
To set the threshold properly, listen to the noise floor with the threshold set at its
lowest setting (-70) while not playing. Increase the threshold value until the noise is
no longer audible. (Use caution, as setting this value too high will cause the down-
ward expander to attenuate the output too quickly and not allow the signal to decay
as long as it should.)
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Ž Press the STORE button two times to save any changes made to the HUSH
parameter.