WhitakerAudio 60 W Stereo Power Amplifier, User And Assembly Manual

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WhitakerAudio
5.3 Assembly of the Power Supply PWB
Check the shipping box for the major component groups. Find the power supply box. Set the other
boxes aside for now. Organize the components for the power supply in a logical manner, grouping
resistors together, capacitors together, and so on. Note that a schematic diagram of the supply is
provided, along with a copy of the PWB component layout. The component layout sheet is a
useful reference as many of the part numbers are obscured when the components are installed.
The estimated time required to complete assembly of the power supply PWB is 2 hours.
After reviewing the Construction Techniques section of this manual, begin populating the
PWB. As the packing envelopes are used, set them aside for recycling. Before beginning, clean
the soldering iron tip.
– Install the “quick disconnect” male tabs using the pads provided on the board. There are
59 positions on the power supply board. Solder in place.
Note that the mounting pins fit tight into the board. This is normal. Use a pair of pliers to hold
the tab while inserting the pins into the PWB. Make sure the PWB is resting on a soft flat surface
while the tabs are installed. It is most efficient to install all of the tabs and then turn the board over
and solder in place. Be careful to not damage the board while installing the tabs. While not strictly
necessary, it is recommended that the flat side of the tab be oriented so as to face the same
direction for all posts.
The proper procedure is illustrated in Figure 5.1.
Clean the soldering iron tip before moving on to the following steps..
– Install R51, R52, R53, and R54 – 100 k
Ω
, 2W . Solder in place, providing about 1/2-inch
clearance above the board.
– Install R55 – 10
Ω
, 20 W . Solder in place, providing about 1 inch clearance above the
board.
– Install R56 – 12 k
Ω
, 5 W . Solder in place, providing about 3/4-inch clearance above the
board.
– Install R57 – 68 k
Ω
, 2 W . Solder in place, providing about 1/2-inch clearance above the
board.