The C9 from Electro Harmonix is a great organ emulator for guitar and we take it one step farther giving you fine-tune control over the C9's on-board "Mod" knob by use of an external expression pedal or an extra on-board expression knob. The C9's Mod knob controls the speed of chorus/vibrato across all the various C9 modes.…this is what you would consider the rotary speaker effect and vibe'y type sounds of organs. By controlling the C9's Mod knob through expression, you can fine-tune your organ modulation on-the-fly and hands-free, just like you would a real organ.
After the Mod is complete, the red "Mod" knob on the C9 pedal will also allow you to set the limit on the maximum heel-down slow speed. [Please note: With the red knob all the way to the left, the expression will not operate.] As you rotate the red Mod knob to the right, you limit the slowest setting of available Mod knob.
Here are the Mod options:
Add on-board Expression Knob:
This option we install an oversized onboard expression knob to the side of the pedal enclosure allowing you to control the C9's Mod knob on-the-fly by using your foot to roll the expression knob. Rolling the on-board expression knob will change the speed of the C9's chorus/vibrato.