Specifications
electrical Installation _
GENERAL
a)
SPEAKER
CONNECTIONS:
To
connect
your speaker
to the amplifier properly, you must know Its
rated
Imped-
ance
. This may be read off tne speaker
nameplate.
Con-
nect
one
speaker lead to
the"
G"termlnal
on the rear apron
and
tne
other
speaker lead to tne nearby terminal
corre-
sponding to the rated speaker Impedance (4,
8,
or 160hms).
Plastic-covered
lamp cord may be used for distonces up to
50 ft. wltn
little
power loss. For shorter
distances,
TV
ontenno lead
can
be
used,
particularly
If
It
Is desired to
run the speaker lead under a rug.
If
It
Is desired to use two similar or Identical
full-range
speakers of the same rated Impedance (either 8 or 16 ohms
only) for
better
sound distribution,
connect
one
speaker
lead of
each
pair to
"G"
and the two remaining leads to
the terminal with a number equal to half of
one
of
the
speaker's
rated
impedance. (It may be necessary to "phase"
the two speakers by reversing both of the leads from
one
of tne
speakers.)
This may not be done if
each
of
the
speakers Is designed for reproduction of a different
part
of the audio spectrum (woofer-tweeter combinations) In
which case a cross-ever network
Is required which
con-
nects to
the
amplifier with only
one
pair
of leads.
b)
MAG.
PHONO
INPUT: This Input is intended for use
with phonographs having magnetic cartridges. The
shield-
ed
lead
from your phonograph should be provided wltn a
shielded
plug.
The loading reslstonce presented to the
cartridge
at
the Input Is
47,000
ohms, which Is the most
generally
suitable
loading resistance for magnetic
cart·
ridges.
c)
TAPE
HEAD INPUT: This Input Is Intended
fer
receiv-
Ing tne
output
signal
directly
from tne playback head of a
tape
deck.
NARTB
tape head
equalization
for 7
1/2
and
15
I.p.s.
tape
speeds Is applied to signals fed In
at
this
Input. The load ing resistance presented to the
tape
head
Is 100
,000
ohms.
d) HIGH lEVEL INPUTS: Two high level Input Jacks
des-
Ignatedas
Tuner and Auxiliary
are
provided for connection
of tuners, tv
receivers,
equalized
and pre-ampllfled
tape
recorder
playback,
and ordinary or
RIAA
equalizing
crystal
or
ceramic
phono cartridges without
adaptor.
A shielded
cable
with a shielded
"phone-type"
plug should be used
to
connect
each
of these sources to the corresponding am-
plifier
input Jack. Unless the source has a low-Impedance
output such as a
cathode
follower{wlth which up to 50
ft.
of
cable
can be used), use tneshortestpasslble connectton
4
and low
capacity
snlelded
cable
(cable having as low
01
25mmfd
capacitance
per foot Is
availab
le) .
If ftle tuner employed has a valume control to adlust ftle
output,
set
this control to
give
about tne same sound level
for
any
given setting of the amplifier
VOlUM
Econtrol
01
obtained
from an
average
orchestra l recording
played
on
your phonograph. If you do
this,
there will not be
any
extreme
change
in sound level when switching from
phono-
graph to tuner or vi ce
versa.
e)
TAPE
OUTPUT: A shielded
cable
(up to 30 ft. may be
used) with a shie lded
"phone-type
" plug should be used
to
connect
from the
TAPE
OUTPUTlack to the Input of
the
~pe
recorder. Any input chosen by the
SELECTOR
Is fed
out
to the
tape
recorder through this
jack.
Phono inputs
fed In
at
MAG.
PHONO
are
of course
equalized
accord-
Ing to tne
RIAA
characteristic
and a ll the inputs are
af-
fected
by the level
and
tone controls.
f)
POWER
CONNECTIONS:
The 117VAC,
250W
re-
ceptacle
is
"live"
or
"dead"
depending on whether the
amplifier power switch is turned on or off .
By
plugging
Into It the line cords of associated equipment (tuner,
tape
recorder,
etc.)
it is possible to turn these components on
or off with the amplifier. Use a
cube
tap if It Is desired
to
connect
more than one
device.
Record changers and
tumtables should be plugged into a wall
outlet
as a
pro-
tection to the mechanisms of these units.
HUM
ADJUSTMENT
a) After checking the amplifier for proper
operation,
re-
move all input cables to
the
amplifier and
makethe
follow-
Ing control settings which hold throughout the process of
hum adjustment:
SELECTOR
at
PHONO,
LEVEL
to 10,
TREBLE
centrci
at
-5,
BASS
control at O.
Next,
procede
01 follows: With your ear held close to the
speaker,
insert
the amplifier power plug into the wall
outlet
and listen to
tne hum
level.
Now pull out the plug and reinsert it with
tne prongs reversed and Iisten again . Choose the prong
position which gives the least hum. Now
connect
the
tuner
input
connector
to the amplifier input
jack,
andwlth
tuner
set between stations and the tuner volume control
set
at
minimum, do the same with the power plug of the
tuner,
using tne 117VAC
convenience
outlet
on the
amplifier
if
desired. Finally
connect
the phono input connector to
the
amplifler
MAG.
PHONO
or AUX. Input (as required)
and
find the lowest hum position for the power plug of
the
phonograph In a wall
outlet.
Do this with the phonograph
off and the pickup arm
at
rest position.