Pedals that stack with the Randall RD40 Diavlo

Friedman BE-OD

Friedman BE-OD takes that high gain character and pushes it toward tight

Beetronics Buzzter Boost Preamp

Feed a high gain signal into Beetronics Buzzter Boost Preamp and it comes out closer to clean boost

Marshall Guv'nor

Marshall Guv'nor takes that high gain character and pushes it toward mid-forward

Electro-Harmonix Deluxe Electric Mistress

Put Electro-Harmonix Deluxe Electric Mistress after Randall RD40 Diavlo in the signal chain, clear of Randall RD40 Diavlo's own gain stage

Hungry Robot Moby Dick V2

Keep Hungry Robot Moby Dick V2 in Randall RD40 Diavlo's effects loop, clear of Randall RD40 Diavlo's own gain stage — goes in the amp's FX loop (or last, into a clean amp)

Walrus Audio Fathom

Keep Walrus Audio Fathom in Randall RD40 Diavlo's effects loop, clear of Randall RD40 Diavlo's own gain stage — goes in the amp's FX loop (or last, into a clean amp)

Warm Audio Pedal 76 Compressor

Warm Audio Pedal 76 Compressor's own tight character is the real reason this is worth trying