The Okko Diablo - Modded Monster Pot Edition is not a factory pedal but a DIY layout: a vero (stripboard) and tagboard version of the Okko Diablo overdrive, modded so the pedal's onboard trimmers are replaced with full-size pots. It was posted on the Guitar FX Layouts blog in September 2012 as a reader request, and it turns the Diablo into an eight-knob build with the Presence and Bass controls brought out to the front panel. For players who build their own overdrive pedals, it is a way to get the Diablo circuit with every control accessible1.
What the mod changes
The stock Diablo hides some of its shaping on internal trimmers. This layout replaces those with pots, giving what the blog described as "an 8 knob version of the Diablo with the Presence and Bass controls external"1. It also includes a switch that supplies the circuits with either 9V or 18V, which the layout's author offered "to give you even more versatility in the dynamics"1.
The build uses two footswitches: one for the main distortion board and one for the boost section, with the SPDT switch selecting either 9V or 18V for the main circuit1.
Controls
| Control | What it does |
|---|---|
| Level | Volume control for the main distortion circuit1 |
| Level+ | Volume control for the boost section; if the boost is bypassed, the Level+ pot is out of circuit1 |
| Presence | External version of an onboard trimmer1 |
| Bass | External version of an onboard trimmer1 |
Build notes and fixes
Builders who have taken this layout on have run into a few wiring quirks worth knowing before you start:
- Builder johnk found the Body control works backwards, and fixed it by moving the "body 1" lead over to "body 3"1.
- The Tone and Bass controls are backwards too; they are linear pots, so the leads should be reversed1.
- Some builders reported a loud squeal or whine when only the main board is engaged at 18V. Velouria FX's fix: "Link Body 3 with Gan 3. Then connect Body 2 to the board instead of Gain 3."1
Not every build squeals. HGE Contraptions' third build, the Gain+ version, had no squeal or whine at any setting, unlike his two Boost+ builds, reporting "Ironically, this has 0 squeal/whine at ANY setting!!"1
What builders made of it
HGE Contraptions, who documented several builds of the layout, reported that "It sounds awesome :)" and shared a demo video of the finished pedal1. On the Presence control specifically, johnk found that "the presence control doesn't do that much (but it does more than my barber LTD presence control does)", so expect a subtle control rather than a dramatic one1.
Where the Diablo went next
The pedal's unusual control wiring runs through the whole circuit: the tone and bass controls are wired backwards as well and use linear pots, so the leads should be reversed when working on them1. HGE Contraptions, which documented the layout, reported "It sounds awesome :)" and shared a demo video of the pedal1.
Videos
Christian Iwanov
Sources (1)
- Guitar FX Layouts: OKKO Diablo, Guitar FX Layouts (tagboardeffects.blogspot.com), 2012-09-14
