WhitakerAudio JC Whitaker 20 W Stereo Integrated Audio Amplifier, Manual

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– Using the available tie-wraps, organize the wiring through the cable clamps adjacent to the
right channel PWB and at the rear of the chassis.
It is recommended that some basic tests be performed on the speaker/headphone circuits
before proceeding:
• Connect a pair of stereo headphones to one of the front panel headphone jacks. Place the
headphones on your head, making sure they are properly oriented (left/right).
• Connect the common (black) lead of an ohmmeter to the back panel ground point.
• Connect the other lead (red) of the ohmmeter to the Ground terminal on the right channel
output barrier strip on the back panel. The ohmmeter should read 0 ohms.
• Connect the red lead of the ohmmeter to the 8 Ohms terminal on the right channel output
barrier strip on the back panel. A click should be heard in the right channel headphone.
The resistance shown on the ohmmeter will be quite low, in the neighborhood of 0.5
ohms. This is normal.
• Connect the red of the ohmmeter to the Ground terminal on the left channel output barrier
strip on the back panel. The ohmmeter should read 0 ohms.
• Connect the red lead of the ohmmeter to the 8 Ohms terminal on the left channel output
barrier strip on the back panel. A click should be heard in the left channel headphone. The
resistance shown on the ohmmeter will be quite low, in the neighborhood of 0.5 ohms.
This is normal.
• Move the headphone plug to the other front panel headphone jack. Touch the red lead of
the ohmmeter to the right channel 8 Ohm terminal and confirm that a click is heard in the
right channel headphone. Finally, touch the red lead of the ohmmeter to the left channel 8
Ohm terminal and confirm that a click is heard in the left channel headphone.
If the results detailed above are not observed, recheck the wiring of the headphone jacks and
the speaker PWBs. Do not move forward until these tests are successfully completed.
5.5.12 Power Management Module
Find the power management PWB, completed previously. This board will be mounted with the
component side facing inward toward the chassis top plate; the foil side will face the chassis
bottom panel. It will be necessary, therefore, to make all connections to the PWB before it is
secured in place.