Hammond L series User Manual

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

Hammond L series Specifications

General

Brand	Hammond
Model	L series
Category	Musical Instrument
Language	English