Pedals that stack with the Red Witch Opia

Univox Uni-Vibe

Run Univox Uni-Vibe after Red Witch Opia in the signal chain, clear of Red Witch Opia's own gain stage

Z.Vex Super Hard On

Z.Vex Super Hard On layers clean boost onto an already fuzzy signal

Walrus Audio Ages

Put Walrus Audio Ages in front and the fuzzy tone leans further toward clean boost

Strymon OB.1 Bass

Strymon OB.1 Bass leans toward clean boost, and that's a real, usable character to pair with

Pigtronix Echolution

Keep Pigtronix Echolution after Red Witch Opia in the signal chain, clear of Red Witch Opia's own gain stage — goes in the amp's FX loop (or last, into a clean amp)

Walrus Audio Melee Wall of Noise Black

Walrus Audio Melee Wall of Noise Black's ambient voice goes after Red Witch Opia in the signal chain — it's not there to compete with Red Witch Opia's own modulated character — goes in the amp's FX loop (or last, into a clean amp)