Pedals that stack with the Electro-Harmonix Flatiron Fuzz

Fulltone OF-2 Octafuzz

Fulltone OF-2 Octafuzz stacks fuzzy on top of the mid-forward already here

Pigtronix Octava Micro

Pigtronix Octava Micro stacks high gain on top of the mid-forward already here

Heavy Metal FX HMFX Phase Riot Factory Second

Heavy Metal FX HMFX Phase Riot Factory Second's modulated voice goes after Electro-Harmonix Flatiron Fuzz in the signal chain — it's not there to compete with Electro-Harmonix Flatiron Fuzz's own fuzzy character

Strymon OB.1 Bass

What Strymon OB.1 Bass brings here leans toward clean boost — that's worth building a pairing around

Electro-Harmonix Memory Boy Analog Delay

Keep Electro-Harmonix Flatiron Fuzz's fuzzy voice out front: Electro-Harmonix Memory Boy Analog Delay goes after Electro-Harmonix Flatiron Fuzz in the signal chain so its modulated voice doesn't muddy it — goes in the amp's FX loop (or last, into a clean amp)

Walrus Audio Mako D1 High-Fidelity Stereo Delay V1

Put Walrus Audio Mako D1 High-Fidelity Stereo Delay V1 after Electro-Harmonix Flatiron Fuzz in the signal chain, clear of Electro-Harmonix Flatiron Fuzz's own gain stage — goes in the amp's FX loop (or last, into a clean amp)