Specifications
Section
AUX
TUNER
PHONO
TAPE
HEAD
1 - 11,
2 - 11,
3-10-11,
3-4-11,
Selector
A
3 - 4
4-5
5-6
6-7
Switch
11 -
12,
1-11-12,
1 - 2 - 11 -
12,
1 - 2 -
12,
B
2 - 3 - 5 3 -
5,
8-9
5 - 8,
8-9
9 - 11
Entries
are
numbers of those switch
contacts
which
are
connected
together
by the rotors
at
the
particular
position.
11
7VAC
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OO
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1'2 W A
TT
AMF'
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2
50
W
HUM
ADJUST
o I
'mm°(i)"Ci)
'I
OUTPUT
16 S 4 G
TOP
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AUX
TUNER
00
MAG.
TAPE
00
PHON
O
HEAD
V
-3
V - 2 0
o
ECCS3!12A
X7
ECCB3
!12AX7
M O Oi:. L
"''''2
"' .GH FIDE L" "
V-1
o
ECC
S3!12AX7
V
-4
o
EL S.4
V - 5
o
ELS4
V
-6
o
EZS1
POW
E R
CO
NS.UMP
TIO
N
l!Ll!CTRON
IC ',," S T co "', C
TRANSFORMER
TEMPERATURE
nONT
The temperature of the transformers used in
the
HF-12 run at less than
1950
despite
the
fact
that
the
safety
limitis
at a much
higher 221
oF.
Although
19SOF
is cool for a transformer, it is very hot to
the
touch.
Transformers
which
seem too hot when
touched
with
the
hand,
are
usually
good and
are
actually
not
overheating.
Output transformers usual!y run
cooler
than
power transformers. Some
output
transformers may
appear
hotter
than others due
to being
located
near
hot components such as
output
and power tubes and power transformers.
OUTPUT TRANSFORMER LOAD
The output transformer and
the
output
tubes of any amplifier
are
subjected
to
severe
stress when
the
amplifier
is
operated
at
a high signal level without a load. To
protect
these components against possible damage, always
have
either
a
speaker
or
resistive load
connected
to
the
output
terminals of the amplifier
while
it is
being
operated.
9