Operation Manual
62
*#1 $OM%OM$2OMOwner’s Manual
Tone-Wheels and Multi-Contact Keys
Digital Virtual Tone-Wheels and Bus-Bar Multi-contact manuals
are used in this organ to replicate the sound, touch and feel of the
original Hammond B-3 as faithfully as possible. Let’s examine
these exclusive patented features a bit deeper.
On modern electronic musical instruments, when a key is depressed,
the sound engine plays. When multiple keys are pressed, the ear
hears multiple notes, but this is an audio illusion. In actuality, only
one voice is sounding at a time, but they are cycling so fast it sounds
as if many notes are playing at once. The onboard processor “scans”
the manual for the notes pressed and feeds that information to the
sound engine. The technology is called “Keyscan” and “Dynamic
Voice Allocation”.
These technologies have worked admirably for synths, but they have
problems for replicating the original B-3 sound and touch. In the
mentioned technologies, there is one contact point, and even that is
subject to latency.
When the Hammond Organ was born in 1934, there was no digital
technology to rely on for the keying system. An ingenious mechani-
cal system was devised using a stack of 9 contacts under each key,
9 bus-bars that ran the length of the manual, and an actuator rod
which would close the contacts from top to bottom as the key was
depressed.
Those bus-bars corresponded to each of the harmonics represented
on the drawbars. A complex wiring harness completed the matrix,
which sent the signals from the closed contacts of the manual to the
drawbars, which allowed, or suppressed the tones from the ever-
spinning, ever-playing Hammond Tone-Wheels.
As the Hammond Organ gained popularity, musicians noted a few
curious side-effects courtesy of that mechanical action. One was a
rudimentary “touch sensitivity”. The actuator rod did not trip all
nine contacts at once, in fact, if the key was not fully depressed,
only a few contacts were closed. This put a randomness in the sound,
and was almost instantly exploited by organists everywhere. Dr.
Lonnie Smith wows audiences by simulating the sounds of Congas
on his Hammond. Jazz, Blues and Gospel organists developed a
move where they lightly “skipped” a chord up the manual, only to
blaze a glissando back down. The sound was, and is, indescribable,
but was an outlet for pure emotion. The great Jimmy Smith in-
vented a registration/technique called “squabbling” that took full
advantage of the manual response.
The other happy side-effect was really a defect. When you consider
the Hammond Keying system, it might be easier to think of it as a
whole bunch of electric switches. By nature; through age, corro-
sion, and contamination, electric switches become “dirty”. Witness
the “crackle” on older radios, or the flicker of a light. The Bus-Bar
switches on Hammond were not exempt, and they started to exhibit
symptoms of noise right from the start. The funny thing was, this
little random chatter gave a distinctive edge to the organ’s sound,
very much like the pick noise on a guitar, or the resinous scrape of
the bow on a violin. The key-click, as it was called made the elec-
tric organ sound less electric, and...more organic! The sound was
fresh and new. The Hammond engineers tried valiantly to correct
this, but happily, they never did.
When the New B-3 was being designed, the hallmark was authen-
ticity. But it didn’t make sense to recreate the mechanical Tone-
wheels of old. After all, it was just sine waves that they put out, and
that’s a child’s game in today’s digital technology. Previously, mod-
ern organ manufacturers (including Hammond) relied on looped
samples of vintage instruments. Close, but no cigar. What if the
entire concept of the B-3 was expressed in modern terms? 96 vir-
tual tone wheels, each putting out their sine-wave constantly, just
as the mechanical ones did, so that when keys were played, the
entry point into each sine wave was random. The resultant phase
relationship between the tones was chaotic, and in this case chaotic
is good. The richness of tone would rival the sweetest vintage B-3.
Whereas the mechanical tone generator was not the way to go, the
bus-bar multi contact keying system could not be rightly dupli-
cated in the digital realm.
Hammond-Suzuki engineers found a way to leap 1930’s technol-
ogy to the cutting edge by being faithful to the past with an eye on
the future. They reinvented the buss-bar multi-contact keying sys-
tem in such a way that the touch is indistinguishable from a vintage
B-3.
Their efforts lie before you today, in your organ.