Pedals that stack with the Fender Pro Junior IV

Zvex 59 Sound

Fender Pro Junior IV's edge of breakup character and Zvex 59 Sound's edge of breakup voice sit in the same lane rather than fighting each other

Vemuram Jan Ray

Run Vemuram Jan Ray into that transparent platform and it finally gets some medium gain

TC Electronic MojoMojo Overdrive

TC Electronic MojoMojo Overdrive leans toward transparent, and that's a real, usable character to pair with

Boss TR-2 Tremolo

Boss TR-2 Tremolo's spring voice goes after Fender Pro Junior IV in the signal chain — it's not there to compete with Fender Pro Junior IV's own edge of breakup character

Origin Effects SlideRIG Compact Deluxe

What Origin Effects SlideRIG Compact Deluxe brings here leans toward compressed — that's worth building a pairing around

Boss RV-6 Reverb

Boss RV-6 Reverb's shimmer voice goes in Fender Pro Junior IV's effects loop — it's not there to compete with Fender Pro Junior IV's own edge of breakup character — goes in the amp's FX loop (or last, into a clean amp)

Catalinbread Cloak

Keep Fender Pro Junior IV's edge of breakup voice out front: Catalinbread Cloak goes in Fender Pro Junior IV's effects loop so its shimmer voice doesn't muddy it — goes in the amp's FX loop (or last, into a clean amp)