Section 6 — Effect Parameters
Edit/Effect Parameters
15
ROM-27 VCF+DISTORT
VCF+DISTORT combines a voltage control filter and a raspy distortion. Three effects can be
obtained: Distortion, Wah-wah, and Auto-wah. The last two functions use the same VCF. These
filters can be disabled or used as EQ if desired. There is a second VCF that exists after the
distortion. It can be set to act like a simple speaker simulator, or it can be modulated in parallel
with the pre-distortion VCF.
VCF+DISTORT Signal Routing
R
L
Main
Outputs
Distortion
Level In
Post-Dist
VCF
Pre-Dist
VCF
Distortion
Level Out
Clip
Env Fol
Env Fol
Distortion
Bypass
Variable
HiPass
Filter
BUS1 Left
BUS3 Left
BUS2 Left
BUS1 Right
BUS3 Right
BUS2 Right
The BUS1, BUS2, and BUS3 MIX parameters can be routed into the effect with different Dry/Wet
mixes.
The parameters available for this algorithm are:
DIST LEVEL IN
Range:
0 to 99
This parameter controls the gain going into the distortion effect. DIST LEVEL IN will boost the
signal level up to 48 dB. For more distortion, use a high input level gain and turn the DIST
LEVEL OUT down to keep the volume under control. For less distortion, use a low gain input
level and a higher output volume.
DIST LEVEL OUT
Range:
0 to 99
This parameter controls the gain coming out of the distortion effect. Generally, if the DIST
LEVEL IN is set high, set this parameter lower to control the volume.
PRE-DIST VCF FC
Range:
1 to 99
This parameter determines the filter cut off frequency before the distortion. Higher values have a
brighter sound. This parameter can be modulated, using a CV Pedal for a wah-wah pedal effect.
To disable the distortion filter, set this parameter to 99. To use as an EQ, set the desired value
and make sure PRE-DIST ENV FOL is +0. To use as the auto-wah, set this parameter close to 1
(lower values) and turn on PRE-DIST ENV FOL.
PRE-DIST VCF Q
Range:
1 to 25
This parameter determines the level and width of the resonant peak at the filter cutoff point.
While the PRE-DIST VCF FC parameter determines where (at what frequency) this peak will
occur, the PRE-DIST VCF Q setting controls the presence of the peak. This setting is important for
the auto-wah effect.
PRE-DIST ENV FOL
Range:
-99 to +99
This parameter determines how much the amplitude of the incoming signal will modify the
distortion filter cutoff frequency. When set to +0, no modification will occur. When set to mid
positive values, the PRE-DIST VCF FC will go high, but then come down to its nominal setting.
When set to negative mid values, the PRE-DIST VCF FC will go low, and then go back up to its
nominal setting How quickly it does so is determined by the ATTACK and RELEASE
parameters. This sound is the auto-wah; positive values will boost the high frequencies, offering
an “oww-oww” sound, and negative values will cut the high frequencies, producing a “dweep-
dweep” sound.
