Heath Heathkit W4-AM Assembling And Using page 6

INTRODUCTION
Most
people are
inclined
to
view
the
meteoric
rise
of the
high
fidelity
craze as something which
has taken place
in the last
two
years. Actually, public
acceptance
of
home
music
reproduction
probably dates
from
the
summer
and
fall of
1948
when
the
Columbia
"LP"
microgroove record-
ing techniques
were
introduced.
It
is
significant that
a
year
earlier, there
was
described
in
the British publication
"Wireless
World," an amplifier
circuit
designed by Mr.
D.
T.N. Williamson which culminated an extensive
search
for
what
the
author described as a perfect amplifier. Within two years,
the
audio
world
had so completely accepted
the circuit
that
it
became
a
standard
for
comparison.
After eight
years, the
design
still
accounts
for by far the
greater percentage
of
all
high
fidelity
power
am-
plifiers in
use
today.
Improvements
have been made,
faults
have been discovered and corrected, other circuits
have
challenged
the
Williamson's
position, but
still
it
stands as the basic high
fidelity
amplifier.
Truly,
the
audio
field
owes Mr. Williamson
a
great
debt.
In
the past four years,
literally
thousands
of
people have
built
and used
Heathkit
Williamson-type
amplifiers.
They
represent a large majority of the units of this type
now
in
use throughout
the
audio-conscious world.
Your
Heathkit
model
W-4AM
Amplifier incorporates
all
the
worthwhile
improvements
and modifications
resulting
from
this
unequalled background.
If
you are
technically inclined, the
information contained
in the
preceding
specifications will
have
satisfied
your questions as
to
the
measured performance
of
the amplifier.
If
you are interested
primarily
in
how
the
amplifier
will
sound
,
your
Heathkit
W-4AMis
capable
of
placing the
burden
of
proof on
the
most
elaborate
and expensive speaker
systems
available today.
Unless you
have,
or expect
to have,
more
than $300.00
to
spend
for a
loud-speaker system, no
significant
im-
provement would
be audible
if
the
W-4AM
were
replaced with any other
commercially
available
power
amplifier,
regardless
of price.
If
more
elaborate
reproducers
were
used,
some
improve-
ment
at
extremely low
frequencies might be expected through
the
use
of
amplifiers
such
as the
Heathkit
W-5M.
In this
discussion,
we
have attempted
to
convince you
that
your investment
in the
W-4AM
kit is
worthy
of
extreme
care
in
construction and
installation.
Hurried or careless construction
can
only lead
to
trouble, either
initially
or
after
some
period
of satisfactory
performance.
TAKE
ENOUGH
TIME
TO DO THE JOB
RIGHT
THE
FIRST
TIME
and you
will
be repaid
many
times
in
personal
satisfaction
and
long,
trouble-free service.
If
you have
built
Heathkits before,
you
will note a
change
in
the
usual step-by-step
procedure
for
assembling and
wiring.
The new
"all-on-one-drawing"
plan
used
in this
manual
has been devel-
oped
to
make
your
work
even
more
enjoyable.
PLEASE
READ THE
MANUAL ALL
THE
WAY THROUGH BEFORE ANY WORK
IS
STARTED.
Only a very small percentage
of
Heathkit
assemblers encounter any
difficulty
whatsoever
in
com-
pleting kits of this kind.
Large
fold-in pictorial
diagrams
are included
in the
manual
for
your
convenience and are
quite helpful
if
attached
to
the
wall above your
work
space.
The diagrams
are repeated
in
small
form
within the
manual
proper.
We
suggest
that
you
retain the
manual
in
your
files
for future
reference
in
the
use
of
the amplifier
and
for
its
maintenance.
UNPACK THE
KIT
CAREFULLY AND CHECK EACH PART
AGAINST THE PARTS
LIST.
DO
NOT
DISCARD
ANY
PACKING MATERIAL UNTIL
THIS
HAS
BEEN
DONE.
In
so
doing,
you
will
become
acquainted with
each
part
and
the
chance
of
accidentally
throwing
away some
part
will
be eliminated. Full size sketches
of
each
of the
parts categories
appear on
Page
16.
Use
this in
checking against the parts
list
and
in identifying
any
questionable
components.