Pedals that stack with the Blackstar Unity 120

fills a frequency gapFills in a frequency range the other side doesn't cover, instead of piling more onto what's already there. (warm → bright)

Blackstar Unity 120 leans into a clean amp's front end, precisely the platform Ashdown Geezer Butler Signature wants

Goes in front of the amp

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

Colorsound Overdriver leans this high headroom tone toward fuzzy, which it doesn't make on its own

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. (fuzzy → octave)

Univox Super-Fuzz layers octave onto an already fuzzy signal

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. (fuzzy → modulated)

Put Boss CE-1 Chorus Ensemble after Blackstar Unity 120 in the signal chain, clear of Blackstar Unity 120'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. (high headroom → compressed)

Outlaw Effects Wrangler's own compressed 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 DD-200 Digital Delay's shimmer voice goes in Blackstar Unity 120's effects loop — it's not there to compete with Blackstar Unity 120's own octave 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.

Keep Blackstar Unity 120's octave voice out front: Boss RV-6 Reverb goes in Blackstar Unity 120's effects loop so its shimmer voice doesn't muddy it — goes in the amp's FX loop (or last, into a clean amp)

Sits in the amp's effects loop