The transformer leads may be trimmed as desired for a neat job,
but be sure you do not cut any of them too short (particularly if
yours is the multi-voltage version, and any change to a different
supply voltage is likely). Cutting the leads too short for re-use
may void its warranty, if it is thought to be defective. Consult the
multi-voltage diagrams elsewhere in this manual fcr connec-
tions to the terminal strips which may differ from the stepby-
step instructions here.
Be sure all strands of each transformer lead are tinned and
soldered together before connection to a lug, so that there is no
possibility of a stray strand touching anything but the lug.
39
4 0
41
42
4 3
44
45
4 6
47
q
4 8
Select the remaining spade lug, and solder it to the black
transformer lead. Connect it to the PS left lug.
Select the .005 (502M) disc capacitor, and trim its leads to
l/2” or less. Wrap one lead around the shaft of the spade
lug which is connected to the PS left (inside) lug. Wrap
the other lead around the shaft of the spade lug con-
nected to the middle lug. Solder both leads. Be sure
there is adequate clearance between these connections,
and that the spade lugs are fully engaged.
Connect the black/white transformer lead to TS lug #5.
(S3). One of these wires was previously soldered to the
lower hole of this lug.
Twist together the two red transformer leads for
neatness, and connect one iead to DB lug #2. Connect
the other to DB lug #3.
Select the .Ol mfd (103M) disc capacitor, and trim its
leads to 3/4" Strip two 1/2” pieces of insulation from the
green wire, and slide one piece over each of the
capacitor leads. Connect one lead to DB lug #2. (S-2)
Connect the other lead to DB lug #3. (S-2) Make sure
both leads are securely soldered to each lug. Here you
could overlook a poor connection.
Connect the red/yellow transformer lead to the center
of the bare wire between the capacitor lugs. (S). Lowest
hum in the unit will be attained when all of the wires
which connect here are as close to the center of this wire
as possible.
Connect the
single
green wire from output terminal LB
to the center of the bare wire next to the transformer
lead. (S).
Connect the
single
green wire from RB to the center of
the bare wire on the other side of the transformer lead.
(S).
Connect the green wire from CL lug #3 between the two
input sockets to the center of the bare wire also. (S).
Select the output assembly modules (the two major
items in the kit). You will note that the only difference,
which identifies the left or the right module, is the posi-
tion of the thermal breaker, which is located between
one pair of output transistors on the heat sink rib. Before
connecting wires to these modules it is best that you take
the time to inspect the underside of the bottom row of
holes to make certain that connections already made to
some of these are well soldered. You will be making con-
nections from the top side to holes 3,5,6,7,8 and 10.
Make sure the proper connection point is clear at each of
these. If it is filled with solder, running the iron along the
underside will uncover the hole, and it may be cleared
with a wooden toothpick.
Now position the right module (with the breaker at the
front when the long bottom row of eyelets is next to the
chassis) with the circuit board
up,
against the side of the
chassis.
Wires will be connected to the holes from the top of the board,
and you must be sure they are soldered securely to the bright
circuit ‘pads’. Each hole is ‘plated through’ - it makes a connec-
tion to the other side of the board - and a good solder connec-
tion which heats the wire and the circuit pad properly will allow
solder to flow through the hole for a secure connection.
Even though the connecting wires are just long enough to make
the connections now, they will be rather long when the
amplifier is completed. That is why working room is limited.
Any wire which is to be connected to a hole on the board should
have a tight, tinned end. The wire supplied in the kit is already
tinned, so it would not normally require additional tinning
unless the tip is frayed. Melt a small amount of solder on the tip
of the iron so that it will make a good contact with both the
bared wire end, and the circuit pad as the wire is inserted into
the hole. Then add additional solder so that there is a smooth,
bright transition from the wire to the board as it cools undisturb-
ed. If you must use a great deal of heat on a connection, make
sure that you have not loosened any adjacent connections in the
process - especially wires from the back side of the board.
The holes #lo and #3 are very close to capacitors on the board.
Be sure heat does not damage these capacitors.
49 Prepare a 5 1/2" green wire. Connect one end to hole #lO
on the circuit board. (S). Make sure it
cannot
contact the
transistor mounting screw near the underside. Connect
the other end to FR lug # 2 (S).
50 Prepare a 6” white wire. Connect one end to hole #3. (S).
Connect the other end to FR lug #4. (s).
51 Select the green and white twisted pair from the output
terminals RR and RB. Connect the white wire to hole #5.
(S). Connect the green wire to hole # 7 (S).
52
q
Select the pair of white wires from RF. Connect the
shorter wire to hole #6. (S). Connect the other wire to
hole
(S).
53 Select 4 of the long sheet metal screws. Take care to see
that no wires are trapped in the process, while you tilt up
the module and fasten it to the end of the chassis. The
screws are inserted between the heat sink fins, and then
engage the chassis.
54
Select the green and white pair of wires from input
socket RS. Connect the white wire from the left to the
top (rear) hole #l. (S). Connect the green wire to hole #2.
(S). These wires should be soldered to the circuitry on the
underside of the board, although they are connected
from the top side of the board, assuring a good connec-
tion. These wires will be specifically positioned later,
9
though they now seem long.
