WhitakerAudio 60 W Stereo Power Amplifier, User And Assembly Manual

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60 W Stereo Power Amplifier
– Find C6 – 0.015 µF, 200 V . Set this component aside. It will be installed later on the
speaker terminal PWB.
– Install C8 and C9 – 0.01 µF disc, 1 kV . Solder in place.
– Install C10 – 0.01 µF, 100 V ceramic . Solder in place.
– Install the four-terminal Molex barrier strip. Solder in place.
– Mount the two 4 terminal Molex contact headers at the Conn1 and Conn2 positions.
Solder in place.
– Find tubes V1, V2, and V3. Set them aside in a safe place. The tubes will be installed
during the final checkout process.
– Find the quick-disconnect connectors. Set them aside; they will be used later.
– Mount the ten 3/4-inch long standoffs on the foil side of the board using the 4-40 hardware
provided. Use a lock-washer on the screw head (component side) of the board. Standoffs
are positioned at the four corners of the PWB and on each side of the tube sockets. Note
that one of the standoff sets includes a ground lug. Place this lug and standoff in the corner
of the PWB closest to the XFMRCT tab. The ground lug goes on the component side of
the board. The screws should be finger-tight for now.
In the following steps the tube sockets will be mounted and connected to the PWB pads.
These steps will require a considerable amount of time and patience. Successful completion is
critical to proper operation of the amplifier.
– Mount the three sockets on their respective standoffs. Pin 1 of the socket can be identified
by a number stamped on the bottom side of the socket. Pin 1 on the PWB is identified by a
square pad. Place the socket in the proper orientation over the PWB so it rests on the
standoffs. The top of the socket (the side the tube plugs into) should face outward. Loosely
tighten the mounting screws. See Figure 5.2 a . For the two octal sockets (V2 and V3),
identify pins 2 and 7 (the heater connections). Bend these pins out away from the socket.
This will facilitate connection of the heater wires later in the process.
– Install connecting wires from the PWB pads to the tube socket pins. Solder in place.
Materials for these steps can be found in the “Tube Socket Hookup” package. Note that