Grounding ?

Which raises another question, why do some amp manufacturers include a ground lift switch.
08-09-09: Phd

The switch only lifts the signal ground from the chassis. Never the safety equipment ground from the chassis/enclosure.
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My recommendation is to check NOT to ground, but between system components. IF there is voltage present, I would consider swapping hot/neutral where the power pigtail gets to the first terminal strip or whatever.
08-10-09: Magfan

If there is a difference of potential, voltage, from one chassis to another then there would indeed be a current flow when the two chassis are connected together by ics.

If the AC polarity is reversed and not correct on a piece of equipment that could cause a higher potential, voltage, from that piece of equipment to another piece of equipment where the AC polarity is correct. I would think the difference of potential would be there whether an equipment ground was used or not. Jmo.....

Something that should be made clear when measuring AC leakage of the primary winding of a power transformer the measurement is actually referenced to the neutral conductor.... The neutral being the grounded conductor which shares the same ground plane as the equipment grounding conductor. That is why most people measure from the chassis to the equipment ground of the recept. But the actual difference of potential is being measured to the neutral.
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Please explain 'leakage'. I have heard the term but am unfamiliar with its use in this case.
08-10-09: Magfan

Charles Hansen on the subject.

1) Reversed AC polarity -- All power transformers have an inherent asymmetry to their construction. The primary winding comprises multiple layers, so that one lead is connected to the innermost windings and the other lead is connected to the outermost windings. This means that one lead has a higher coupling capacitance to the core of the transformer. Please remember that the AC supply is also asymmetrical, with the neutral lead essentially being at ground potential (assuming there is not a fault in the house wiring). The result is that one orientation will give a higher AC leakage current to the chassis of the amp (and worse sound) than the other orientation.

Not all transformer manufacturers use consistent markings on their transformers so that the correct orientation can be identified, and not all amp manufacturers pay attention to this even if the transformer is correctly marked. The result is that many audio products have a random chance of being correctly oriented.

http://www.audioasylum.com/audio/general/messages/449743.html

Sean.... thread here on Agon.
http://forum.audiogon.com/cgi-bin/fr.pl?htech&1014011751&openusid&zzSean
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