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Two
positions
of
the
''Mode Switch",
"Vibrato",
and "Delayed
Vibrato"
also
effect
the
normal
Hammond
percussions
I
when
they
are in
use (See
Note
above).
2-9.
FREQUENCY
DIVIDER
-
When
using the
"Chime"
voice,
it is
necessary
to create a
\
1-1/4
harmonic
for the
proper reproduction
of
the
"Chime"
tone.
This
is
accompHshed
by
routing the 5th
harmonic
into
an
ampli-
fier
made
up
of
Q315
and Q316.
Q317
'
rectifies
and
further amplifies
this
pulse
which
is
then
fed to
a
two-stage
frequency
divider,
made
up
of
Q318, Q319, Q320,
\
and Q321.
The
output of
this
second
I
frequency
divider
is
then routed
back
to
I
the "Selector
Switch",
and
is
used
as
one
of
the
harmonics
in
the
"Chime"
voice.
NOTE
j
Because
a
frequency
divider
can
cv
I
handle only
one frequency
at a
time,
any
attempt
to
play
two
or
more "Qiime"
notes
at
a
time
will
result in distortion.
^
2-10.
CYMBAL AND
BRUSH -
The "Cymbal-
Brush"
switch
when
in
the
"off"
position
disables
the keying functions necessary to
produce
the
"Brush"
effect.
With
the
"Cymbal-Brush"
switch
in
any one
of
the
"on"
positions,
the
8th
harmonic
of
the
lower
manual
is
disabled
and
this
harmonic
busbar
is
used
for
keying
the
"Brush"
effect.
The
pedal
signal
(keying) contact
is
used
to
activate
the
"Cymbal"
effect
each time
a
pedal
is
depressed.
,2-11.
BRUSH KEYING -
With
the
"Cymbal-Brush"
'
switch
in
any
of
the
ON
positions,
the base
of
Q322
is
routed
now
to the
8th
harmonic
busbar
in
the
lower manual.
Anytime
a
key
is
depressed, the base voltage
of
this tran-
sistor
is
routed
to
ground,
and
this
stage
'
stops conducting.
The
attendant
rise
in
collector voltage
is
impressed
on one
plate
of C608.
The
other
plate
of
C608
responds
by
driving excess electrons
off to
ground
through
resistor
R624.
The
resultant posi-
tive
voltage
is
then
fed
through
D203
to the
base
of
Q323,
the
"Brush"
gate.
To
the base
of
this
"Brush"
gate
is
also
fed the noise
from
the noise generator
Q324.
This noise
is
now
tuned
in
the
collector
circuit
and
fed to the
"Cymbal and
Brush" ampUfier
i
which
comists of
Q325
and Q326.
2-12-
CYMBAL
KEYING.
- Anytime
a
pedal
is
depressed, the pedal
signal
is
routed
to the
pedal drawbar.
A
portion of
this
same
signal
is
also
fed to
Q327
and Q328. These
stages
amplify
and
shape
the
signal
and
feed
it
through
R61
2 to the base of
Q330, and
through
R613
and
D205
to a
R/C
storage
network and
the base
of
Q329. The
signal
developed
across
R616,
the emitter
resistor
of
Q330,
is
rectified
by
D204
and
this
posi-
tive
voltage
is
applied to the base
of
Q331,
the
"Cymbal"
gate,
turning
it
on.
At
the
same
time, the
output of
Q328
is
being
rectified
by
D205
and
slowly
appUed
to the
base
of
Q329.
When Q329
is
biased into
conduction
it
depletes the base
bias
nor-
mally
supplied
to
Q330
through
R612
and
Q330
stops conducting. In
this state,
no
signal
is
available
at
the emitter
of
Q330
to
be
rectified,
and Q331,
the
"Cymbal"
gate,
slowly turns
off.
To
the base
of
this
"Cymbal"
gate
is
also
fed the noise
from
the noise generator,
Q324.
This noise
is
tuned
in
the
collector
circuit
of
Q33
1
and
fed to
Q325
and
Q326
the
"Cymbal
and
Brush"
amplifier.
2-13.
BRUSH
AND CYMBAL
AMPLIFICATION.
-
After being
ampUfied by
Q325
and Q326,
the
"Brush and
Cymbal"
signals are
routed
to
a
voltage divider consisting
of
R604, R605, and
R606.
It is
then tapped
by
the
switch
and
routed
to
R602
the
overall
level
control.
This
is
located
on
a
terminal
strip
on
the
lower organ
shelf,
near the
AO—
43
ampli-
fier.
The
wiper of
the
overall level
control
(R602)
now
feeds into the
AO—
43
ampli-
fier
through
R601
and
C318
to Pin 7
of
V8.
To
enhance
the
"Brush and
Cymbal"
effects,
a small high
frequency speaker
is
attached
to the
main
ampHfier.
It is
located
under
the
lower
right
hand end
block
on
the organ.
2-14.
POWER
SUPPLY.
-
Power
supply
chassis
is
suppHed
with
+340
volts
DC
from
AO-43
amplifier.
+80
volts
required
for
percussion
assembly
is
obtained
from
voltage divider
R690, and
R69
1
.
+
1
2
volts
is
obtained
from
Zener Diode
D201.
2-15.
L-100-1
SIX-VOICE
PERCUSSION
CIR-
CUITRY.
-
2-16.
POWER
SUPPLY
(See Figure
5-7).
-
Power
supply
components
are
located
in
the
power
supply
chassis
assembly
(127-7
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