WhitakerAudio J C Whitaker 20 W Stereo Audio Amplifier, Manual

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– Locate the power supply choke, L51. Examine the mounting holes. Note that two holes are
provided within the confines of the base of the choke. These holes are used for two of the
support standoffs for the power management PWB. Install the 2.5-inch standoff using
countersunk 3/8-inch long #6 screws. Include a lockwasher between the chassis and the
standoff. Tighten.
– Install the power supply choke using the #6 hardware provided, carefully guiding the leads
through the hole in the chassis. Be sure to include the grounding lug wire. Route the
grounding wire through the chassis along with the choke leads.
All of the transformers have now been installed.
5.6.6 Install Remaining Chassis Components
Locate the remaining chassis-mounted components, which include the following:
• Panel-mount potentiometer R55
• Top chassis decal
– Mount R55 – 100
Ω
potentiometer – Hum Balance Control. Mount the device from the
top of the chassis and secure with the lockwasher and nut provided. Position the device so
that when at the center of travel, the white dot on the knob points toward the back of the
chassis.
– Carefully peal off the backing for the top chassis decal. Position it on top of the chassis,
behind tubes V5 and V6. Apply the decal.
5.6.7 Wire the Transformer Leads
Find the female “quick-disconnect” connectors. In the following steps, the transformer leads will
be connected to their respective terminals on the circuit boards using these connectors. The lead
lengths from the various transformers may need to be trimmed to remove excess length. Make
sure to keep sufficient lead length to permit organized cable routing.
5.6.7.1 Cable Organization
To facilitate cable organization, it is advisable to install expandable flexible cable sleeving on
some of the transformer leads. A supply of this material is provided. To properly perform the
following steps, it will be necessary to have a heat gun on hand. (A common hair dryer may be