Electro Harmonix positioned the B9-U within their 9 Series as an organ machine effect pedal designed to transform the signal of a guitar or keyboard into the sound of a full-body electric organ. It shipped with nine presets, each tuned to emulate classic tonewheel and combo organ tones drawn from the 9 Series lineage.

The unit offered dedicated controls for percussive attack level, modulation speed, organ volume, and dry volume — allowing the player to blend the processed organ signal with the original dry signal for layered textures. The B9-U accepted input from both guitar and keyboard sources, with a 1 MΩ input impedance suited to passive instrument pickups and a 500 Ω output impedance for driving standard amplifier inputs or audio interfaces. Current draw is 100 mA at 9 V DC, and the pedal measured 4.0″ wide × 4.75″ long × 2.25″ high. An EHX 9.6DC-200 power supply unit was included. The unit was designed for use alongside the C9 for expanded dual-keyboard possibilities.

Owners requiring service, calibration, or integration advice should consult a qualified guitar or keyboard technician familiar with effects signal chains.