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
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.
390 Select the remaining spade lug, and solder it to the black transformer lead. Connect it to the PS left lug.
4 0 u 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.
41Connect the black/white transformer lead to TS lug #5. (S3). One of these wires was previously soldered to the lower hole of this lug.
42G Twist together the two red transformer leads for neatness, and connect one iead to DB lug #2. Connect the other to DB lug #3.
4 3 ci 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.
44 0 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.
4517 Connect the single green wire from output terminal LB to the center of the bare wire next to the transformer lead. (S).
4 6 0 Connect the single green wire from RB to the center of the bare wire on the other side of the transformer lead.
(S).
47 q Connect the green wire from CL lug #3 between the two input sockets to the center of the bare wire also. (S).
4 8 0 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 II Prepare a 51/2" 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 0 Prepare a 6” white wire. Connect one end to hole #3. (S). Connect the other end to FR lug #4. (s).
51 C 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 #8 (S).
53Select 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 0 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, though they now seem long.
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