Pedals that stack with the Ampeg GV-12UK

clean platform takes the driveA clean, high-headroom stage takes on dirt it can't generate by itself. (transparent → low gain)

The Geezer Butler's doom-heavy bass distortion pushes the GV-12UK's natural jazz-blues voice into real heaviness.

Goes in front of the amp

clean platform takes the driveA clean, high-headroom stage takes on dirt it can't generate by itself. (transparent → low gain)

The ODB-3's bass-voiced overdrive gives the GV-12UK's natural jazz-blues tone real rock grit.

Goes in front of the amp

clean platform takes the driveA clean, high-headroom stage takes on dirt it can't generate by itself. (transparent → fuzzy)

Run Fulltone OCD Obsessive Compulsive Drive into that transparent platform and it finally leans toward fuzzy

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.

Put EarthQuaker Devices Grand Orbiter V3 after Ampeg GV-12UK in the signal chain, clear of Ampeg GV-12UK's own gain stage

Goes in front of the amp

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

Vox Valvenergy Silk Drive's own smooth character is the real reason this is worth trying

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.

Boss RV-6 Reverb's shimmer voice goes in Ampeg GV-12UK's effects loop — it's not there to compete with Ampeg GV-12UK's own compressed character — 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.

Put Boss DD-200 Digital Delay in Ampeg GV-12UK's effects loop, clear of Ampeg GV-12UK's own gain stage — goes in the amp's FX loop (or last, into a clean amp)

Sits in the amp's effects loop