Technical input that might be of interest, though not providing exactly what Greg requested. This from my bro-in-law who is a talented musician (keyboards his forte) and studio owner (engineering, production, mastering). He’s in the AllMusic Guide for what that is worth. He owns a couple of Hammonds including a B3 that he refurbished. Safe to say he’s intimately familiar with how they work. His comments:
"Key click" and "percussion" are two different things. They are commonly confused with one another.
Key click was the result of an electrical contact being made when a note is depressed on the organ. Key click was considered a flaw and Hammond used frequency filtering to help suppress this.
There are ways to accentuate the key click by tapping directly out of the organ’s preamp and going straight into a mixing console or guitar amp. Organists like Keith Emerson, Jon Lord and many others utilized this sound.
Percussion was a design feature that was introduced in 1955 on the B3 and C3 models and then later it was available on most other models. The percussion effect is a set of four tabs on the top right of the console that when depressed, adds varying degrees of harmonic attack to the note. Sort of like when you strike a marimba or vibraphone. It is in no way like the sound of key click.
"Key click" and "percussion" are two different things. They are commonly confused with one another.
Key click was the result of an electrical contact being made when a note is depressed on the organ. Key click was considered a flaw and Hammond used frequency filtering to help suppress this.
There are ways to accentuate the key click by tapping directly out of the organ’s preamp and going straight into a mixing console or guitar amp. Organists like Keith Emerson, Jon Lord and many others utilized this sound.
Percussion was a design feature that was introduced in 1955 on the B3 and C3 models and then later it was available on most other models. The percussion effect is a set of four tabs on the top right of the console that when depressed, adds varying degrees of harmonic attack to the note. Sort of like when you strike a marimba or vibraphone. It is in no way like the sound of key click.