Press the "Bank" up or down pedals on the left side of the GFX-8 until you reach the group that has the patch you want to edit, then press pedals "1" through "4" to select the patch.
Twist the four parameter knobs to change the sound quality of the patch. The parameter knobs are labeled "Presence," which changes the ultra-high frequency; "Treble," which changes the high frequency; "Middle," which changes the medium frequency; and "Bass," which changes the low frequency.
Determine the types of effects you want to include in the patch. You can choose from the Drive, MOD and DLY/REV effects categories. Drive has a variety of distortion effects and an acoustic guitar simulator. MOD is used for modulation effects, such as wah and flanger. DLY/REV is used for delay and reverb effects.
Check the types of effects you can use for each category. Each category has 22 selectable effects. When looking at the effects, you'll notice that they are broken up into 11 groups of two, separated by a line. The effect above the line is from the A section, and the effect below the line is from the B section.
Turn the "Effect" knobs under Drive, MOD and DLY/REV to "A," "B" or "Off." Choosing A or B allows you to select an effect from that group. Selecting "Off" disables that effect category.
Move each of the effects knobs to the effect that you want to use on your patch.
Turn the "Gain" knob to adjust the intensity of the Drive effect, "Parm Select" to adjust the intensity of the MOD effect, and "Parm Value" to adjust the intensity of the DLY/REV effect. Continue making adjustments and testing the sound of your patch until you find the sound you want.
Press the "Total" button. When editing patches, the Total button is used to changed the name of the effect. Patch names can have up to eight characters.
Turn the "Parm Select" knob to move the location of the cursor.
Turn the "Parm Value" knob to change the character that you want to enter. After entering the character, turn the "Parm Select" knob to move to the next position of the name.
Press the "Store" button twice when you have finished creating and naming your new patch to save it to the GFX-8.
Push the "Bank" up or down pedals to choose the group where you want to store the patch.
Press one of the pedals labeled "1" through "4" to choose the pedal you want to push for the patch.
Push the "Store" button to save the patch to the effects processor.