Harman Kardon HK20 User Manual

Input Connection:
To
connect
your
HK20
to
a
monaural
preamplifier
attach
the
shielded
cable
supplied
with
the
amplifier
between
the
INPUT
jack
on
the
HK20
and
the
out-
put
jack
on
the
preamplifier.
If
you
are
connecting
the
HK20
to
the
AX20
con-
verter
connect
the
shielded
lead
between
the
HK20
INPUT
jack
and
the
LEFT
PREAMP
OUT
jack
on
the
AX20.
Input Level Control:
This
control
adjusts
the
gain
of
the
HK20
power
amplifier.
For
monaural
application
it
should
be
set
to
maximum.
For
stereo
use
it
is
set
to
balance
your
other
amplifier.
When
used
in
conjunction
with
the
Harman-Kardon
AX20,
the
INPUT
LEVEL
control
should
be
used
in
the
following
manner.
1.
Turn
the
INPUT
LEVEL
control
on
the
HK20
to
zero.
9.
Turn
the
volume
control
on
your
AX20
to
normal
listening
level,
and
set
the
balance
control
to
the
mid-position.
3.
Play
a
stereo
record
or
tape.
The
left
channel
should
be
completely
in-
operative
since
the
INPUT
LEVEL
control
on
the
HK20
is
set
at
zero.
4.
Slowly
rotate
the
HK20
INPUT
LEVEL
control
until
the
left
channel
perfectly
balances
the
right.
5
Allow
the
INPUT
LEVEL
control
to
remain
set
in
this
position.
Further
adjustment
should
not
be
necessary.
All
additional
channel
balancing
should
be
made
with
the
balance
control
on
the
AX20
converter.
ADJUSTMENTS
Hum Adjust Control:
This
control
is
accessible
from
the
underside
of
the
chassis
with
the
bottom
plate
removed
and
from
the
top
of
the
unit
with
the
cage
removed.
It
is
physi-
cally
located
between
the
EZ81
rectifier
tube
and
the
6CG7.
To
adjust,
allow
the
amplifier
to
thoroughly
warm
up.
Disconnect
the
input
from
the
preamplifier
stage
and
turn
the
INPUT
LEVEL
control
to
maximum.
While
listening
to
the
hum
level
in
your
speaker,
turn
the
HUM
ADJUST
con-
trol
for
minimum
hum.
Output Tube Balance Control:
The
BALANCE
control
is
accessible
from
the
underside
of
the
chassis
with
the
bottom
plate
removed
and
from
the
top
of
the
unit
with
the
cage
re-
moved,
it
is
physically
located
between
the
EL84
output
tubes.
This
control
is
preset
at
the
factory
and
should
not
be
touched
unless
the
output
tubes
are
changed
or
a
periodic
yearly
check
is
required.
When
adjustment
is
necessary
follow
the
outlined
procedure.
1.
Turn
the
INPUT
LEVEL
control
on
the
HK20
to
minimum.
2,
Remove
the
shielded
connecting
cable
from
the
INPUT
jack.
3.
Slowly
rotate
the
OUTPUT
TUBE
BALANCE
control
for
minimum
hum
in
your
speaker.
4.
If
the
hum
level
is
inaudible,
set
the
OUTPUT
TUBE
BALANCE
con-
trol
to
the
exact
center
position.
5,
For
those
who
demand
supercritical
adjustment
of
this
control,
the
adjustment
should
be
made
with
an
IM
analyzer.

Harman Kardon HK20 Specifications

General

Brand	Harman Kardon
Model	HK20
Category	Amplifier
Language	English