MC wrote:Your power amplifier is not grounded. If this effect is new then you must have had something else connected that provided ground. Note that this effect is normal (about 90 V AC, but high impedance/low current) and typical for ungrounded switched power supply systems.
Matthias, I have to partly disagree with what you said, a healthy ADI-2 cannot cause this:
• The voltage caused by ADI-2 Pro's PSU is exactly 1/2 of the mains voltage, not 90V.
This hints to the fact that it's by design, without opening the PSU I predict there are two small capacitors of equal value connecting phase and null to the secondary, a common practice.
Or it's the result of stray coupling between primary and secondary, but this usually would result in different voltages if you turn the plug to reverse phase and null, which is not the case.
• I can, by measurement, agree that normally the resulting current is extremly low, several magnitudes below what is dangerous for humans, nothing to worry if the ADI-2 PSU is in factory condition.
• Coming to the topic starters problem:
No static discharge as low as only 1/2 of the mains voltage, in a typical home system, can give the sensation of "beeing shocked".
In fact, the effect is so small that you need to know how to provoke it and what to watch out for to feel it.
• The amount of "shock" sensation described leads to the conclusion:
Something is broken, either in ADI-2's PSU or in the power amplifier used, or something got wet inside.
Much more current then usually is flowing, if this gets worse it might become dangerous.
And, yes, the power amplifier is obviously not grounded, by design, by defect, or by miswiring of the mains cabeling.
Every device in the system can be the cause, need not necessarily be ADI-2.
A professional electrician should have a look!
This is NOT a DIY task.
• One alternative explanation:
The topic starter has either a new floor carpet, or new shoes that cause charging him personally to several 10,000V (!) static voltage, that discharges each time he touches something grounded.
As children we did this intentionally to see and feel the spark.
If it's only personal static charge it shouldn't only happen on the Hifi, but when touching other grounded metal stuff too.