The Wurlitzer 4600 Series
Electrostatic Organ
As
we continue looking through the Wurlitzer 4600 series instruments reed
unit, here we see both the first octave of bass reeds that generate the
16' octave of pedal tones, and we also see the top octave. This system
over-all gives surprisingly good sounding bass which has plenty of fundamental
and also a few of the lower order harmonics to add definition. Notice
that on these reeds the pickups are in slots in the bakelite strips so
that in addition to adjusting them closer or farther from the reeds, you
can also change their relative position, closer to the center for more
fundamental, or closer to the front end for slightly more harmonic development.
In looking at two of these instruments, one a 4600 that was designed for
pops playing, and the other a 4602 which is the 32 pedal classical version,
it appears that the reed pickups for the pedals in the 4600 are closer
to the center to give a bass tone with slightly less harmonic content.
This would be a little more like the 16' tibia bass in a theater pipe
organ whereas putting the pickups closer to the front would give a bass
tone a little like the 16' wood diapason of a larger classical pipe organ.
Essentially the 4600 and the 4602 are identical, but there are slight
differences. Both have the same basic sound and the same tone generation
system. The vibrato on the 4600 is more pronounced on the "full"
setting, and although the voices are the same, the names on the stop tabs
are different.
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Left and also above [closeup]. Two
views of the first or sub octave of reeds which provide notes 1-12 when
using the 16' pedal stop. These reeds have only a single pickup
and notice that the pickups are set close to the centers of the reeds.
This produces a tone which is mostly fun-damental with relatively small
amounts of the second, third, fourth and fifth harmonics. The resulting
tone is reasonably suggestive of a 16' tibia on a theater pipe organ,
however the second harmonic on the electronically generated tones is
somewhat evident whereas there is almost no second harmonic at all in
a pipe organ tibia rank. Roll mouse cursor over picture for more details.
Left. Here is a look at
the very top octave of reeds. Notice at the right that there is an extra reed
for the very top C. All of the rest of the reed pans have 12 reeds in each
one, but the the top octave has thirteen in order to have a pitch available
for top C.
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Right. Here's another close
look at the top octave of reeds the white arrows point to two of the actual
reeds. Notice that these tiny reeds are so small that the actual reed
strip is narrower than the slots in the screws that you see here. There
is only one pickup because these reeds only need to produce flute tone.
