Pedals that stack with the Fender FSR Blues Junior IV (Black, Greenback Speaker)

pushes an amp at the edge of breakupPushes an amp already sitting at the edge of breakup over the line. (edge of breakup → low gain)

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

Goes in front of the amp

Zvex 59 Sound leans toward edge of breakup, and that's a real, usable character to pair with

Goes in front of the amp

Origin Effects DELUXE61 Amp Tremolo & Drive's own edge of breakup 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.

Put JHS 3 Series Harmonic Tremolo after Fender FSR Blues Junior IV (Black, Greenback Speaker) in the signal chain, clear of Fender FSR Blues Junior IV (Black, Greenback Speaker)'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. (dynamic → compressed)

Origin Effects SlideRIG Compact Deluxe'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.

Keep Fender FSR Blues Junior IV (Black, Greenback Speaker)'s mid-forward voice out front: Electro-Harmonix Memory Boy Analog Delay goes in Fender FSR Blues Junior IV (Black, Greenback Speaker)'s effects loop so its analog warmth 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

Keep Boss DM-2 Delay in Fender FSR Blues Junior IV (Black, Greenback Speaker)'s effects loop, clear of Fender FSR Blues Junior IV (Black, Greenback Speaker)'s own gain stage — goes in the amp's FX loop (or last, into a clean amp)

Sits in the amp's effects loop