Pedals that stack with the Hiwatt Custom Studio Stage MkIII 20/40W 2x12 Combo

Fjord Fuzz Fjaer Spring Reverb

Fjord Fuzz Fjaer Spring Reverb stacks fuzzy on top of the mid-forward already here

Fjord Fuzz Midnattssol

Put Fjord Fuzz Midnattssol in front and the mid-forward tone leans further toward fuzzy

JHS Angry Charlie

JHS Angry Charlie's own voicing points at Marshall-style amps, and Hiwatt Custom Studio Stage MkIII 20/40W 2x12 Combo delivers it

Artec SE-NGT

Keep the SE-NGT ahead of the Custom Studio Stage MkIII — it silences noise before the amp's own articulate clean kicks in.

Mu-Tron Bi-Phase

Into Hiwatt Custom Studio Stage MkIII 20/40W 2x12 Combo, Mu-Tron Bi-Phase is right at home: it's built around Marshall-style amps

Catalinbread Cloak

Hiwatt Custom Studio Stage MkIII 20/40W 2x12 Combo leans into Marshall-style amps, precisely the platform Catalinbread Cloak wants — goes in the amp's FX loop (or last, into a clean amp)

EarthQuaker Devices Dispatch Master V2

EarthQuaker Devices Dispatch Master V2's own voicing points at Marshall-style amps, and Hiwatt Custom Studio Stage MkIII 20/40W 2x12 Combo delivers it — goes in the amp's FX loop (or last, into a clean amp)