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Insert the tinned 8” black wire from the bottom of the power supply board
into the TB3 hole marked N12 and solder it on the top side.
5 Volt Power and Ground wires
Locate the red/black 18 AWG bonded-paired wire (zip cord). Prepare a 14” length per the
following diagram:
5V power and ground wire installation
Done? (
)
Twist and tin the bare end of the 14” red wire.
Twist and tin the bare end of the 14” black wire.
Insert the tinned 14” red wire from the bottom of the power supply board
into the TB9 hole 5V and solder it on the top side.
Insert the tinned 14” black wire from the bottom of the power supply board
into the TB9 hole marked BGD and solder it on the top side.
Connect Power Input wires and install the Power Supply
Locate the 22 AWG stranded wires that come from the switched outlet. Remove ¼” of
insulation from the ends. Twist and tin the free ends of the black and white wires.
1.
Twist the insulated portion of the black and white wires together. Forming a
twisted pair like this minimizes hum.
2.
Insert the white wire into the hole marked AC2 on the component side of the
power supply PCB, and solder that wire on the solder side. Cut off any extra lead
length on the solder side.
3.
Insert the black wire into the hole marked AC1 on the component side of the
power supply PCB, and solder that wire on the solder side. Cut off any extra lead
length on the solder side.
4.
Install the power supply PCB into the chassis. For now,
loosely install just one
screw
, the 4-40x0.25” zinc plated (silver colored) SEMS screw through the PCB
hole nearest the back corner of the chassis into the stand-off on the chassis floor.
The AC1 and AC2 terminals will be next to the back corner of the enclosure.
Installing just one screw allows you to swing the PCB out of the way to make
installing the transformer easier.
5.
Fasten the transformer to the right side wall of the preamp in the manner shown in
Figure 18. This operation may be easier if you turn the chassis on its side so that
gravity helps you. Prevent scratches on the side of the chassis by setting it on a
towel.
