Grounding ?


Guys,

I currently have a cheater plug on my amplifier which made a substantial difference in clarity and focus. I read somewhere that the amp should be grounded and to use a cheater plug on another unit. Which component should I use the cheater plug on, Pre, CD player or DA?

Thanks,
Wig
128x128wig
If you're really paranoid you can simply connect the chassis of the primary grounded component (typically preamp) to the chassis' of other componentry. Any reasonable size (black insulation color for appearance) (14awg & stranded for flexibility) household electrical wire with spade or ring tongue crimp lugs should be more than sufficient. Basic creativity should suffice; loosen a chassis screw on the back panels & tie the lugs thereto.

However if it was me I absolutely wouldn't bother (take a hint from Milimetr) but I would never advise someone else against safety grounding for liability reasons alone. Perceive the implication, vs. the statement. In regard to sound quality now that's the issue, which many might be more likely to focus on.

Yes you can simply voltmeter-probe to the chassis, with the other probe referenced to an AC outlet ground, to check for stray leakages. The compoment would be energised but not cabled to anything else. You need to probe on a bare metal surface or press the probe tip down hard to penetrate the paint; judiciously of course and in a strategic location (such as the bottom panel) so as not to harm the finish.
Bob_b
Yes I am paranoid, but that doesn't matter in this case.
My personal system has NO hum or other internal noise issues.

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.
Once everything agrees, the hum should disappear?
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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Exactly, J,
there will be voltage present if the ground plug is used or not! Connecting 2 pieces under these conditions is using 1 of 'em as 'local ground'.

Please explain 'leakage'. I have heard the term but am unfamiliar with its use in this case.

Have I just been lucky all these years in NOT ever having a bigtime hum problem?
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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