Keyboard shortcuts

Press ← or → to navigate between chapters

Press S or / to search in the book

Press ? to show this help

Press Esc to hide this help

Vibrato/Chorus Scanner

The Hammond's internal modulation effect, developed in the early 1940s and put into production right after WWII (models BV/CV = vibrato only; BCV/DV = vibrato + chorus).^[raw/articles/wikipedia-hammond-organ.md]

How it works

A scanning delay line: a capacitor bank is scanned electronically in sequence, so the signal passes through a continuously varying delay — a phase-modulation vibrato. The chorus setting mixes the delayed (modulated) signal with the dry signal, producing a shimmering doubling effect.

  • B-2/C-2 (1949): vibrato selectable per manual.
  • B-3/C-3 (1954): V1–V3 / C1–C3 depth selector.
  • Distinct from the Leslie: the scanner is pitch/phase modulation inside the organ; the Leslie is physical acoustic rotation outside. Players use both — e.g. vibrato off + Leslie tremolo, or C3 + chorale for gospel warmth.