WhitakerAudio J C Whitaker 20 W Stereo Audio Amplifier, Manual

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20 W Stereo Audio Amplifier
5.6 Chassis and Final Assembly
Unpack the chassis and position it on the work surface. Place a towel or other soft covering on the
work surface to avoid scratching the finish. Note there may be some rough edges on the drill holes
and cutouts. Be careful to avoid cuts or nicks.
– Find the side chassis handles and install using the #8 hardware provided. Use the handles
during the following construction steps to ensure a good grip on the chassis.
– Find the chassis bottom plate and feet hardware. Install the feet at the four corners of the
bottom plate using the hardware provided. Note that four self-tapping #6 screws are
provided. Save these for the final step of assembly—mounting the bottom plate to the
chassis.
The estimated time for completion of the following steps is about 10 hours. The chassis and
final assembly process is divided into a number of sub-sections, allowing the builder to proceed at
a measured pace. A full-size image of the completed chassis (bottom view) is provided. Refer to
this image as you complete the steps that follow.
A few general comments on wiring are appropriate at this point. The chassis accommodates a
number of cable clamps to organize wiring within the amplifier. In general, the following
guidelines apply:
• Cable clamps are provided on each side of the chassis (2 each side) to accommodate audio
cabling for the right and left channel amplifiers. The cables are: 1) input, and 2) feedback.
• Cable clamps are provided in the center of the chassis to accommodate the interconnection
of the various circuit boards. In general, wiring follows a U-shape, beginning at the front
panel, looping near the rear portion of the chassis, and returning to the front panel.
• Wiring for transformers is typically direct—leads go directly from the transformer to the
connection terminal.
5.6.1 Front Panel Components
Collect the front panel components, which include the following:
• Front panel handles
• Two 100 k
Ω
linear dual potentiometer – Volume controls (R35, R36)
• One 35 mm jack