Rocktron VooDu Valve Online User Manual page 20

The PRE EQ (EXPERT) function is available in all presets—regardless of which
configuration is currently recalled.
This function allows you to shape the tone prior to the distortion stage. Considerable
tone variations can be achieved by modifying these pre-distort EQ parameters.
The PARAMETER SELECTcontrol will allow you to access these PRE EQ parameters:
LF LEVEL The pre-LF (low frequency) LEVEL parameter allows you to cut or
boost the low frequencies from -15dB to +6dB prior to the distortion
stage. This EQ section is a shelving-type.
LF FREQ The pre-LF (low frequency) FREQUENCY parameter allows you to
select a frequency band with an upper frequency between 63Hz and
500Hz to be cut or boosted by the pre-LF LEVEL parameter.
MID LEVEL The pre-MID LEVEL parameter allows you to cut or boost the mid-
band frequencies from -15dB to +12dB prior to the distortion stage.
MID FREQ The pre-MID FREQUENCY parameter allows you to select a mid-band
center frequency between 500Hz and 4KHz to be cut or boosted via the
pre-MID LEVEL parameter.
MID BW The pre-MID BANDWIDTH parameter determines how wide or
narrow the bandwith of the selected mid-band frequency is (in octaves).
A small bandwidth only boosts or cuts frequencies close to the center
frequency, while a large bandwidth affects the level of frequencies up to
two octaves from the center frequency.