May. 2008 DD-7 3. Insert the plug into the OUTPUT B jack. Verify that the CHECK LED lights up orange. 6. Insert the plug into the OUTPUT B jack. Verify that the CHECK LED lights up orange. fig.DD-7-wave-7.eps_75 fig.DD-7-wave-7.eps_75 4. Adjust the MODE knob to the ANALOG position. 7. Adjust the MODE control to the REVERSE position. Verify that the CHECK LED lights up orange. Verify that the CHECK LED lights up orange. fig.DD-7-wave-7.eps_75 Verify that the waveforms are not clipped. fig.DD-7-wave-7.eps_75 Verify that the waveforms are not clipped. 5. Disconnect the plug from the OUTPUT B jack. Verify that the CHECK LED lights up red. 10.
Residual Noise Check fig.DD-7-wave-8.eps_75 Make the connections shown below to the INPUT and OUTPUT jacks on the DD-7. INPUT A: Connect a 47-k Ω dummy plug. INPUT B: Connect a 47-k Ω dummy plug. OUTPUT A: Connect a noise meter (JIS-A) and monitor speaker. OUTPUT B: Connect a noise meter (JIS-A) and monitor speaker. 1. Adjust the MODE knob to the ANALOG position. Verify that the CHECK LED goes dark. Verify that residual noise is -93.0 dB or less. Verify that no audible noise or shock noise is present. 2. Adjust the MODE control to the REVERSE position. Verify that the CHECK LED lights up orange. Verify that residual noise is -99.0 dB or less. 3.
Detach the plugs from the INPUT A and INPUT B jacks and switch off the power. Verify that no audible noise or shock noise is present. 11. Battery Operation Check 1. Insert batteries into the battery compartment, connect the AC adaptor (to INPUT A), and switch on the power. Make sure the CHECK LED lights up. 2. Rapidly disconnect the AC adaptor and verify battery operation. * Failing to disconnect rapidly triggers a reset. If reset occurs repeatedly, a problem such as faulty contact in the AC adaptor jack may be present. If the CHECK LED is dark, check the battery voltage. 16