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where
you con enjoy
a
normal
volume
level
and
are act-
ually
listening.
When
the situation requires
a very
soft
level,
or
you are simply providing
background
music, in-
sertion of
loudness
compensation (IN
position) will
elimi-
nate
a
thin
"tinny"
sound
quality
by
boosting lower
boss
tones
to
a more
audible
level.
The
reason
we
prefer that
you
limit
the use of
loudness
compensation
is
thot
compen-
sation tends
to
create the impression
that
you
are
sitting
close
to
an orchestra
that
is
playing
softly.
This carries
over
to
what would
normally be
loud orchestral passages
and
may
therefore
be
grossly
contradictory
to
the sense
of
the music.
When
no compensation
is
used
for
soft
listen-
ing
levels,
it
seems merely
that
you
are
sitting at
a
greater
distance
from
the orchestra, but the sense of the
music
is
not disturbed
except
for
the
loss
of audibility
mainly
at
the
extreme low
frequencies.
However,
many
people pre-
fer
the
pleosure of hearing the
full
frequency range
even
at
very
low
listening levels
and
they
will
employ
loudness
compensation
more
often.
LISTENING
TO PHONOGRAPH:
Set the
SELECTOR
switch
to
PHONO
if
you have a magnetic
cartridge
or
a
ceramic
cartridge
with
adaptors interposed
between
the
cartridge outputs
and
the
MAG.
PHONO
1
and
2
Inputs.
(The
RIAA
equalization provided
at
the
PHONO
position
is
now
the
intemotionalstondard
In
the
recording
industry
for
both
monophonic and
stereophonic records
and
is
olso
a very good compromise
For
the
most importontof the older
monophonicrecording
characteristics.) Set the
SELECTOR
switch
toAUX
A
or
AUX
B
If
you
are using
a
stereophonic
crystal
cartridge (Ronette)
connected
to
either
AUX A
or
AUX
B
inputs.
To
play
a
stereophonic
record.
Initially
set
the
MODE
switch
to
MONOPHONIC PHONO
ond
balance
the
two channels
as
described
obove
in
"LEVEL
BALANCE BETWEEN CHANNELS". When
this
Is
done,
set
the
MODE
switch
to
one
of the
STEREOPHONIC
posi-
tions for
stereo
listening.
To ploy a
monophonic
record,
the
procedure
Is
exactlythe same, only
the
MODE
switch
remains
set at
the
MONOPHONIC PHONO
position,
pro-
viding
the identical signol
in
both channels with
mixing
of the
inputs
for
vertical
rumble
cancellation.
If
it
is
desired
to listen to
the
monophonic
record
on one
channel
alone,
set
the
MODE
switch
to
the
CHECK
AMPLIFIER
1
orCHECK
AMPLIFIER
2
position
depending on which chan-
nel
is
desired.
Note
that
in
the
latter
case there
is
no
mixing
of the
Inputs
and
vertical
rumble
is
not cancelled.
The useofthe
LOUDNESS
switch,
ond
the
BASS
and TREBLE
controls,
is
described above.
LISTENING
TO
TAPE
DECK
(direct
connection
to
tape
head):
Set the
SELECTOR
to
TAPE.
NARTB
tape equali-
zation
is
provided
in
both channels
for
the tope
speed
selected
with
the
TAPE
switch
on
the
front
panel.
One
position
Is
for
7
1/2
Ips
tapes
and
the
other
for
3 3/4
ips
tq>es.
These
equalizations are the
industry
standard
for
pre-recorded stereophonic and monophonic
topes.
The
remainder
of
the
procedure
is
the
same
os
"Listening
to
Phonograph"
described obove,
listening
TO
AMONOPHONIC
source
CONNECT-
ED
TO
AUXILIARY
Al,
AUXILIARY
fll,
TO
MONO-
PHONIC
AM
BROADCAST,
OR TO
MONOPHONIC
FM
BROADCAST
:
Set the
SELECTOR
to
AUX
A,
AUX
B,
AM-
FM,or FM-MULTI.
respectively
and
the
MODE
switch
to
MONOPHONIC
TUNER,
AUX.
Use
the
BASS
and TREBLE
controls as
described
previously.
LISTENINGTOA
STEREOPHONIC
SOURCECONNECT-
ED
TO
AUXILIARY
Al ond
A2,
AUXILIARY
Bl
and
B2,
AM
and FM,
FM
ond
FM
MULTIPLEX:
Set the
SELECTOR
to
AUX
A,
AUX
B,
AM-FM,
or
FM-MULTI
respectively.
Set the
MODE
switch
ot
STEREO
NORMAL
or
STEREO
REVERSE. The LEVEL, BASS ond TREBLE
controls ore
set
os
described
previously.
MAKING
RECORDINGS:
Tape
recordings
may
be
made
by
connecting
the recorder
to
the
TAPE
OUTPUT
jacks.
Pleose note
that recordings
cannot be
made
on
tape decks
unless those
decks
are
equipped
with
the electronics re-
quired
for
recording.
maintenance
Your
preamplifier
should
require
little
service
except
for
normal tube repiocement.
To
facilitate servicing,
remediol
and
trouble-shooting
pro-
cedures
have been provided
in
the
TROUBLE
SHOOTING
CHART
that follows.
VOLTAGE
andRESISTANCE
CHARTS
ore
also
provided
os
an
aid
to
locating defective
com-
ponents.
On
the
schematic diagram,
AC
mid-frequency
(1
kc)voltage
sensitivities
are
shown
at
most of
the grids
for
full
2
volt
output
in
order
to
permit
a
careful,
stoge-
by-stoge
check
of
the
operation.
TROUBLE-SHOOTING
PROCEDURES
Connect
the leads from the stereo cartridge
and
from the
two
speakers
to
the amplifier.
These connections
are
made
os
described
in
the section "Electrical Installation".
Set
the
SELECTOR
switch
at
PHONO
and
the
MODE
switch
at
STEREO
NORMAL
or
REVERSE.
Play a
known
high
quality
stereo
recording
on
the
phonogroph.
if
there
is
no
oufout
to
the
speaker
or
if
the output
is
low
or
audibly
distorted,
precede
to
the
checks
for
those
symptoms.
If
there
is
excessive
hum
In
the output,
disconnect the
phono
input
cable from
the amplifier
ond
short
the
phono
input
jack to
chassis.
If
the
hum
disappears, the trouble
is
not
In
the amplifier but
in
the
phonograph
or
in
the connection
to
the
amplifier.
In
each
case,
check
for
the trouble
in
the amplifier
which
seems
defective.
If
both
amplifiers
ore defective,
check
the
power
supply.
Each
channel can
be
dealt
with
separately
by
setting
the
MODE
switch
to
CHECK
AMPLIFIER
I
or
2
as
desired.
The
causeof phonograph
hum maybe
a
metal pick-up arm
or
motor
not
grounded
to
the
preompi
if
ier
chassis (run
these
ground
leads directly
to
the preamplifier
chassis,
not
to
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