Zoom GFX-8
Guitar effects processor
Custom Distortion guide
In the GFX-8ED software you can create two custom drives,
including custom distortion settings.
In the editor, this setting can be accessed via:
Drive module > then select Custom1 or Custom2
and
File > New > Custom Distortion (to design the four modules, which you can use in a Custom Drive)
Custom Distortion Editor: Receive for loading Custom distortion parameters from the Gfx-8, Store to save your settings in your Gfx-8. Other buttons are for pre-and post-filter cascades and for selection of the distortion characteristic.
The image shows the structure of a Gfx-8 drive unit. This structure is just as present in the pre-programmed drive types, but not obvious. You only see this structure when you program your own drive unit.
You have to distinguish between the drive module and the modules used in it.
In a "Custom drive" you can embed the modules of the other pre-programmed drive types as well.
Look to the following scheme.
Structure of a Custom Distortion with its four independent modules
Each custom drive unit consists of the modules "Distortion character" followed by three filters for the treble (High Char), middle (Mid Char) and low frequencies (Low Char). Corresponding to these four modules we have four controllers in the patch editor.
Controllers selecting the four modules that are used in a custom drive.
With the potentiometers for each module you choose either one of the already pre-programmed distortions or modules from your own distortions designed with the Custom distortion editor. Zoom uses the term "custom drive" for the a complete drive unit which is a distortion module + pre- and post-filtering. On the other hand you have a "Custom distortion" wich is a set of four modules that can be used in a Custom drive but they do not need to be used!
"Pre gain" control defines the strength of the distortion.
"Tone" determines whether the heights are lowered
before the guitar sound reaches the distortion.
"Gain" determines the output volume of the drive module.
The Custom Distortion Editor
With this editor you can design the four modules of each Custom distortion.
The first module consists of a three-stage filter
in front of the distortion and a selectable pre-defined distortion curve.
If you click on the first button "Special 1" you get
into this window with pre-filtering and distortion.
Custom Distortion sub window 1
In the example above a treble booster filter has been combined with a classic tube distortion. With the button "Send", the amp simulation will be sent to your GFX-8 via Midi. If you want to use this distortion in a sound patch, you have to select "Custom1" or "Custom2" in the Drive module and you have to set the "char" control on S1 or S2.
After setting of the filter values you first have to press the "Calc" button, so that the filter is calculated. After that press the "Send" button which sends the modelled filter and distortion to the GFX-8.
In addition, you can design filters for post-filtering of the distortion sound and place them in the High Char, Mid Char and Low Char modules.
Hint:
You can achieve the greatest sound effect with bandpass
filters of different center frequencies. Sonically, this
corresponds to a wah pedal with different pedal positions.
You can place three different band passes in the High, Mid and Low Char
module.
These filters can be programed freely.
They are not limited to the high, mid and low frequency range.
Since you can freely select which filter module is used in a Custom drive,
you can chose from 6 different band passes that you have created
(each Custom distortion has 3 post filter modules).
The filter editor is a bit awkward to use because
you have to enter numbers and you cannot hear the results in time.
It may be a better idea designing proper filters with an
audio software, and then put the values found into the GFX-8 editor.
You must save the custum distortion settings in a separate custom drive file. They are not stored in the patch files.
Likewise, the distortion settings must be send separately to the Gfx-8. After that they are available in the drive module in the Custom1 and Custom2 setting.
Contact: op@engon.de
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