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PRELIMINARY!
Be
lure
oil
tube*
are
firmly
seated
In their
sockets
and
that the tube shteldsare
making good
contact
with
their
bases.
As
Initial
adjustments,
set
these controls
as follows:
LEVEL
at
zero,
LOUDNESS
at ten,
BASS
at
zero.
Turn the amplifier
on by
turning the
TREBLE con-
trol
clockwise from
OFF
and
set
It
at
zero
Initially.
LISTENING
TO
PHONOGRAPH:
Set the
SELECTOR
to
one
of
the record equalization
positions
on
the
dial.
Do-
ing so automatically
selects
thephonograph
Input
plugged
Into
PHONO
INPUT
1
or
PHONO
INPUT
2.
For help
In
choosing the recording curve appropriate
to
any
parti-
cular record,
refer to
thechart
titled
"RECORD EQUILh
ZATION
SELECTION".
When
In
doubt
as
to
which
equl
II-
zaflon
Is
most
appropriate, use
RIAA, which
Is
the best
compromise
for
all
records.
Keep
In
mind
that
while
the
positions
offered
caver most recording curves
likely to
be
encountered,
additional separate
and
variable
bass
and
treble response adjustments
are necessary
for folly satis-
factory
results.
These
may
be
necessary
to
compensate
for
the over-all
characteristics
of your audio system
(In-
cluding
room
acoustics).
Inexact
matching of
the actual
recording
characteristic
by any
of the equalizations pro-
vided, and,
above
all,
the
particular
tastes
of the
listener.
4
LEVEL
&
LOUDNESS CONTROLS:
Simply
stated,
the
purpose of
the
LOUDNESS
control
Is
to
provide
compen-
sation for
the Increasing Inefflctencyof the
human
ear
In
hearing
bass
and
treble
with decreasing
volume
level
.
The
LOUDNESS
control, as
It
Is
turned counter-clockwise
from
maximum
clockwise
rotation,
not only decreraes the
volume
but
Increasingly
emphasizes
the bass
and
treble
according
to
the
Fletcher-
Munson
curves (curves
developed
from
a
statistical
study
of
this
effect).
An
uncompensated
LEVEL
control
Is
also
provided
to
"set"
the
LOUDNESS
control
for
proper operation
In
any
system,
and
also
for
the purpose of
adjusting
the
listening level
when
going
from quiet program
material to loud
program
material or
the reverse without occasioning
a change
In
the
loudness
compensation.
To
"set"
the
LOUDNESS
control
at
any
time, perform these operations
In
the order gjv
^p
to
avoid
blasting
or
possible
damage
to
speakers of
low power-hand-
ling
capacity:
a)
Turn the
LEVEL
control to zero; b)
Turn the
LOUDNESS
control to ten;
c)
With
high
level
orchestral
program
material
being fed
to
the
amplifier
from
your
phonograph
or tuner,
advance
the
LEVEL
control set-
ting until
a
relatively loud
listening level
Is
obtained,
d) Turn
down
the
LOUDNESS
control
until
your normal
listening level
Is
obtained with
the
LEVEL
control
set
as
just
described. Proper loudness
compensation should
now
be
obtained at
any
listening level
adjusted
to
with the
LOUDNESS
control
.
The same
reference
LEVEL
control
setting will
be
suitable
for
both
phonograph and
tuner
list-
ening
If
the
volume
control
of the tuner has
been
adjusted
as
described
In
the
"High
Level
Inputs" sub-section
of the
"Electrical
Connections"
section.
When
selecting
Inputs
which do
not
have
level ad|usts,
such
as
tv
or
a
crystal
cartridge
connected
to the
AUX.
Input,
It
may
be
desir-
able
to set the
LEVEL
control to
zero beforehand
and
then
bring
up
the
LEVEL
control to
obtain the desired
list-
ening
level to
avoid
blasting.
Note
that the
LEVEL
con-
trols
affects
the output
to
tape recorder
available at the
TAPE
OUT
jack but that the
LOUDNESS
control
has
no
affect
on
this
output.
BASS
CONTROL:
The
plus sign
on
the
right
side
of
the
dial
Indicates that
clockwise
rotation
from
the
mid-point
(0)
Increases
(boosts)
ban
response; the
minus
sign
on
the
left
side Indicate that
counter-c lockwtse
rotation
from the
mld-potnt decreases
(cuts)
ban
response.
There
Is
no
In-
teraction
with the
TREBLE
control. Start
all
adjustments
with
this
control set
at
the
mid-point (0^ which
Is
called
the
"flat" position
since
ban
response
Is
neither
cut nor
boosted at
this
setting. This
control
does
affect
theout-
put
to
a
tape recorder from the
TAPE
OUT
jack
to
permit
"touching
up" of
the record equalization or reducing the
effect
of
low
frequency
disturbances
when
recording
on
tape.
Set
It
at zero
If
no
effect during recording
Is
de-
sired.
e
TREBLE
CONTROL:
The
plus sign
on
the
right
side
of
the
dial indicates that
clockwise
rotation
from
the
mid-point
(0)
Increases
(boosts) treble
response; the
minus
sign
on
the
left
side Indicates that
counter-clockwise
rotation
from
»hs
mid-point
decreases
(cuts)
treble response.
There
Is
no
Interaction
with
the
BASS
control.
Start
all
adjust-
ments with
this
control
set
at the mtd-potnt
(0),
which
Is
called the
"flat" position
since
treble
response
Is
neither
cut nor boosted at
this
position. This control
does
affect
the output
to
a
tape recorder from the
TAPE
OUT
jack
to
permit "touching
up"
of
the
record equalization or reduc-
ing the effect of high
frequency
disturbances
when
record-
ing
to
tape. Set
It
at
zero
If
ho
effect
during recording
Is
desired.
LISTENING
TO
TUNERS,
TV,
TAPE RECORDERS:
With
the
SELECTOR
switch
set at
TUNER,
TV, TAPE
or
AUX-
ILIARY, the
corresponding high
level
Input from
a
radio
tuner,
tv,
tape
recorder,
second
tuner or
crystal
cartridge
will
feed through the
amplifier.
Adjustmentof
the
volume
control
on each
source
Is
discussed
In
the
"Electrical
Con-
nections" section
under "High Level
Inputs"
and
again
under "Lever
&
Loudness Control"
In
this
section.
MAKING
RECORDINGS:
Tape, wire,
or
disc recordings
'"ay
be
made
by
connecting
the recorder
to
the
TAPE
OUTPUT
jack.
See
"TAPE
OUTPUT"
under
ELECTRICAL
CONNECTIONS"
and
the
"BASS
CONTROL"
and "TRE-
BLE
CONTROL"
operating
Instructions.
With
the output
of the recorder connected
to
the
"TAPE INPUT"
jack,
turning the
SELECTOR
switch
to
TAPE
readies the
ampli-
fier for
playback
of
the recording.
RECORD EQUALIZATION SELECTION
Recordsare
made
with boosted
volume
In
the
treble
range
to
mask
surface noise
and reduced volume
In
the bass
range
to
conserve groove space
and
reduce
distortion.
As
there
was no
universally
accepted
standard
of
treble
boost
and
bass
cut
In
recording before Spring 1954, re-
cords of
which
the masters
were
made
before
this
date
may
require
any one
of several
different equalizations
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