The main dirt circuit of the Giant Hogweed uses a single op amp in a topology similar to a RAT.
A secondary octave up/down circuit can be switched on and will be mixed with your dry signal before hitting the gain stage. The individual volume controls for the octaves define how much (if any) of each gets mixed in.
The Texture control allows to mis-bias the chip and introduce gated sounds and texture. This imbalance of headroom also allows to clean up the dirt with the guitars volume control, even with buffered pedals before it, so it can be placed pretty much anywhere in the signal chain.
The tone is a “BMP” style control that pans from bass to treble. Mids adds, well, mids.
As these are analog octaver circuits, they track single notes fine but get messy with chords. You may like that mess though.
It runs on standard (Boss style) 9V power supply (no battery) and uses a relay bypass with soft switches.
Controls:
Level – Adjusts the overall volume of the pedal.
Gain – Adjusts the amount of distortion.
Tone – Adjusts the tone, from all bass at the left to all treble at the right.
Mids – Adjusts the amount of mids.
Texture – Misbiases the main gain stage, adding sag and gating.
Up – Adjusts the level of the upper octave.
Down – Adjusts the level of the lower octave.
Find more detailed info and demos on the main product page.