Pedals that stack with the Marshall Studio JCM900 SN20H

pushes an already-dirty tonePushes an already-dirty tone harder and tightens it up. (high gain → mid-forward)

Browne Amplification Gritador takes that high gain character and pushes it toward mid-forward

Goes in front of the amp

pushes an already-dirty tonePushes an already-dirty tone harder and tightens it up. (high gain → tight)

Friedman BE-OD pushes a high gain tone toward tight

Goes in front of the amp

pushes an already-dirty tonePushes an already-dirty tone harder and tightens it up. (high gain → clean boost)

Feed a high gain signal into Analog Man King of Tone and it comes out closer to clean boost

Goes in front of the amp

sits in the right chain slotPlaced for where it does its job cleanly in the chain, not for a tonal interaction with the anchor. (high gain → lush)

Run Laney Spiral after Marshall Studio JCM900 SN20H in the signal chain, clear of Marshall Studio JCM900 SN20H's own gain stage

Goes in front of the amp

sits in the right chain slotPlaced for where it does its job cleanly in the chain, not for a tonal interaction with the anchor. (high gain → lush)

Put Hungry Robot Moby Dick V2 in Marshall Studio JCM900 SN20H's effects loop, clear of Marshall Studio JCM900 SN20H's own gain stage — goes in the amp's FX loop (or last, into a clean amp)

Sits in the amp's effects loop

sits in the right chain slotPlaced for where it does its job cleanly in the chain, not for a tonal interaction with the anchor. (high gain → modulated)

Hungry Robot The Borderland's modulated voice goes in Marshall Studio JCM900 SN20H's effects loop — it's not there to compete with Marshall Studio JCM900 SN20H's own high gain character — goes in the amp's FX loop (or last, into a clean amp)

Sits in the amp's effects loop

shapes the dynamic responseShapes how the tone responds to picking dynamics rather than its frequency or gain.

What Crazy Tube Circuits Golden Ratio brings here leans toward tight — that's worth building a pairing around

Goes in front of the amp