The knobs cover Volume, Cut, Output, Bass, Treble and Boost. Alternate functions set room ambience and the speed and intensity of the vibrato. Boost can model a 1960s germanium treble booster or the preamp of a 1970s tape echo.

A Speaker switch changes between three speaker types, named Silver, Blue and Green after the original drivers. Each has its own microphone setup, and the cabinet can be bypassed when feeding a real speaker.

Released in 2022, Ruby '63 shares its format with the Dream '65 and the later Lion '68. The UAFX app edits sounds over Bluetooth, four presets live in the pedal, and MIDI over USB handles changes. Stereo inputs and outputs support a 4-cable connection.