WhitakerAudio J C Whitaker 20 W Stereo Audio Amplifier, Manual

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20 W Stereo Audio Amplifier
– Install the front-facing hardware for filter FL51, which should be oriented as follows:
screw head (6-32 x 3/8) / flat washer / FL51 mounting tab / chassis / lockwasher / standoff
/ flat washer / screw head (6-32 x 3/4). The acrylic cover will be installed later. As with
the other mounting tab, the front-facing tab may be notched for easier assembly. After
both mounting screws of FL51 have been installed, tighten both.
5.6.4 Install Printed Wiring Boards
The following steps require patience. Do not force the boards and tube sockets into position, but
rather work them in carefully and slowly.
– Locate the Amplifier PWB #1 (right) assembly. Remove the screws that secure the sockets
to the standoffs, and remove the screws in the standoffs at the four corners of the PWB (if
present). Set these in a convenient place.
– Check the heater wiring on the foil side of the board. Position so the wiring will rest
against the chassis when secured in place.
– Carefully place the right channel amplifier PWB in position from the underside of the
chassis.
– Install the six 4-40 x 3/8-inch mounting screws from the top of the chassis to the socket
standoffs on the circuit board. Some adjustment may be needed for the sockets to achieve
proper alignment. After the sockets are in position, install the four screws for the four
standoffs at the corners of the PWB. Do not tighten the screws until all screws have been
threaded and the sockets properly extend through the chassis cutouts so they are flush with
the top of the chassis.
– Locate the Amplifier PWB #2 (left) assembly. Remove the screws that secure the sockets
to the standoffs, and remove the screws in the standoffs at the four corners of the PWB (if
present). Set these in a convenient place.
– Check the heater wiring on the foil side of the board. Position so the wiring will rest
against the chassis when secured in place.
– Carefully place the left channel amplifier PWB in position from the underside of the
chassis.