OKKO Diablo - Modded Monster Pot Edition

Request.  A modded version of the Okko Diablo with pots replacing the onboard trimmers and scope for even more!  This will give you an 8 knob version of the Diablo with the Presence and Bass controls external.  If you're feeling particularly brave you could even replace the trimmers on the booster to make an 11 knob Okko Diablo Behemoth, but I'll leave that one up to you! :o)

Includes a switch which will supply the circuits with either 9V or 18V to give you even more versatility in the dynamics and headroom of the effect, and the main effect and boost have been done on separate boards so you can just make the main circuit if you want to, or maybe even add your favourite boost instead of this one.  The main board will fit in a 1590B and there's a prize for the first person to do it with all 7 main board pots! :o)

Tip: I have heard a recommendation that the 100R resistor from Q3 source can be replaced with a 1K trimmer to help bias things up, but again I'll leave that choice to you as to whether you add a trimmer or experiment with resistor values (800 ohms worked for the guy who suggested it).

Info about the original from Okko:

The Diablo is a versatile low to medium gain overdrive with an exceptionally dynamic response. It preserves the character of your instruments and is very sensitive to your playing technique. Thanks to the effective and musical controls, the Diablo works equally well with any kind of guitar, amp or playing style. People use it for so many different sounds, you would hardly believe that they use the same pedal.

Besides the usual Gain, Tone and Level knobs, the Diablo has some more interesting controls:

FEED affects the amount of bass in the input signal. You know the problem: an overdrive sound gets muddy rapidly if the input signal is too bass heavy (that’s why the treble booster was invented).  With the FEED control you can make even the fattest neck humbucker sound clear and transparent or beef up weak pickups a little.

The BODY control takes effect on mids and compression.  Another important feature is the HEADROOM SWITCH. Set to the "HI" position, an internal electronic voltage doubler is activated – the Diablo runs on 18 Volts from a regular 9 V battery or power supply.  The higher voltage gives more dynamic range, more headroom and tighter bass – just try it!

The Diablo comes in two versions: the regular one and the Diablo Gain+ with two footswitchable gain settings.