Finding and eliminating audio hum in a complex installation can be a very frustrating task. Often, the easiest way to identify the culprit(s) is to systematically eliminate devices from the audio chain. If Cable TV is connected to any component in the system, start by unplugging the Cable completely, preferably right at the wall jack. If this eliminates, or greatly reduces the hum, it is worth a call to your Cable company. A quick fix, assuming your cable is round 75Ω wire, is to attach a 75-300Ω transformer to the end, then attach a 300-75Ω transformer to that, so that the end is back to a round 75Ω wire. There are commercially available antenna lead isolators which may provide additional insula- tion from electrical surges.
The DC-1 does generate minimal amounts of RF energy and is in compliance with FCC rules and CE standards. If some interfering noise is noted, move AM loop and FM "T" type antennas away from the DC-1 and reorient them as necessary. Use shielded cable for FM and TV antenna feeds.
Severe power surges or sags can confuse the DC-1 memory. To correct, or if you simply want to start over, restore the factory defaults with the procedure described at the end of this section.
Turn off all amplifiers. Turn the master power switch on the DC-1 rear panel OFF, wait 10 seconds, then turn it ON again. This causes the unit to run a diagnostic self-test routine which takes a couple of seconds. If the DC-1 LCD displays normally at the end of this test, no problems have been found with the DC-1 circuitry. If the internal tests fail, the LCD may display an error message, or no message at all. If this happens, contact Lexicon.
If you find that your custom settings are routinely being corrupted, the lithium battery in the DC-1 may be faulty. This part is not field- replaceable — contact Lexicon.
If the unit is still behaving erratically, perform the Restore Defaults procedure described on the following page.
