WhitakerAudio J C Whitaker 20 W Stereo Audio Amplifier, Manual

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– 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 Rectifier PWB. Remove the screws that secure the socket 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.
– Carefully place the rectifier PWB in position from the underside of the chassis. Make sure
the board is properly oriented. See Figure 5.11 for guidance.
– Install the two 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 to achieve proper
alignment. After the socket is 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 socket properly extends through the chassis cutouts so it is flush with the top of the
chassis.
– Once all PWBs have been installed, tighten by using two screwdrivers—one from the
bottom of the chassis and the other from the top. Turn in opposite directions. Be careful
not to over-tighten. Be careful to not scratch the top finish. Note that the preamplifier
power supply PWB will be installed later.
5.6.5 Install Transformers
The chassis is shipped with the output transformers and power supply transformers packaged
separately. This is a precaution to avoid damage during shipping due to the weight of these
components. As the transformers are installed, the chassis will become quite heavy. Use the side
handles to move the chassis. It may be useful to have a second person assist during the following
steps.
In order to reach the PWB terminal posts, the lead length on the transformer wires is critical.
As typically supplied, the leads should reach their respective posts. To avoid the possible need to