Tweakers' Asylum

RE: You would still have a ground loop.

70.56.4.35

This Post Has Been Edited by the Author

In Reply to: RE: You would still have a ground loop. posted by Pooge on July 04, 2007 at 14:26:42

Here is the facts, as we know them:

The wiring,
* One truly dedicated 120V branch circuit. Consisting of one each dedicated, hot conductor, neutral conductor, and equipment grounding conductor.

* Two separate 120V circuits. A 3 wire multi wire branch circuit consisting of two hot conductors (each connected to a breaker fed from each Line in the electrical panel L1 and L2). One shared neutral conductor, and one shared equipment grounding conductor.

* The truly dedicated circuit feeds the preamp and what ever source equipment.

* The two separate circuits,
if a power amp is feed from each separate 120V circuit a hum is heard through the speakers.
Note..... There is only one equipment grounding conductor for both circuits feeding the power amps....
Added note, at idle both amps theoretically are drawing the same amount of current so the two power transformers primary windings are in series with one another and being fed by a difference of potential of 240 volts nominal.

* If both power amps are plugged into only one of the separate circuits, that circuit being fed from the same Line in the electrical panel as the truly dedicated circuit, the final result, no hum is heard through the speakers.

*Still the same equipment grounding conductor.

* Why no hum??

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