Crown CE 2000, Справочное руководство

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CE-Series Amps with an Attitude!
The Dastardly Duo: Dr. Hum and Mr. Buzz
If you have noticeable hum or buzz in your system, you may
want to check your cable connections to see if the unwanted
noise is being introduced via a ground loop. To determine the
proper wiring, first check whether the output from your source
is unbalanced or balanced (if you don’t know, refer to the unit’s
back panel or instruction manual). If the source is balanced,
refer to Figure 4.3; if it is unbalanced refer to Figure 4.4. Next,
determine if the source’s power cable is floating (ungrounded,
2-prong) or grounded (3-prong). Finally, if the source is unbal-
anced, check the type of wiring: twin-lead or single coax.
Hum and Buzz Tips
1. It is imperative that all of your electrical equipment share the
same power ground reference.
2. Unless you are interfacing to a microphone, the shield of the
cable should only be connected at one end. (See Fig. 4.2.)
3. Do not pass signal ground between electrical components in
a grounded source system.
4. If you wish to avoid ground loops, it doesn’t matter if you lift the input or output
signal ground for your system topology, just be consistent. Personally I prefer to lift
the input signal ground and it has always been successful...so far!
5. NEVER use a ground lift adapter to lift the power ground on a 3-wire AC cord; this
is not its intended purpose. It is better to have it SAFE than SILENT!! Look for the
true source of the noise.
6. Even when interfacing to an unbalanced load, it is preferable to use two-conductor
shielded cable.
7. Get rid of the lighting company!