Why is a 1.5-2 volt AC signal on my Neutral line?

If I understand your post correctly, it sounds to me like you've got a defective interconnect (or two) somewhere.

I think you are saying that with ALL of these components simultaneously connected into the system, if you connect your meter between the ground sleeves of various rca connectors and safety ground on the power strip, in some cases you see a substantial voltage and in some cases you do not.

If that is the correct interpretation, it would seem to say that a cable somewhere is not properly tying the grounds of the connected components together.

Regards,
-- Al

Guys, I think we need clarification from the op, as I implied in my earlier post and as Jim requested. My suspicion is that the reference to 1.5 to 2.0 vac on the "neutral line," on some components only(!), does NOT refer to the ac neutral.

For one thing, he referred to "the neutral side of the interconnect." Also, how would he be able to measure the voltage between ac neutral and ac safety ground individually for each component, without opening it up and probing internally under the chassis?

So as I indicated in my earlier post, I suspect he is referring to an ac voltage between circuit ground (as measured on the ground sleeves of rca connections) and ac safety ground. As Jim and I indicated earlier, if he is seeing a significant difference among those readings for different components, while the components are interconnected, he's either got a defective interconnect or a defective circuit ground connection on one or more of the rca jacks. Either of which could certainly account for a hum problem.

Best regards,
-- Al

I second Shadorne's comments.

So it sounds like you are saying that the 1.5 to 2.0 vac that you measured was between the circuit ground/chassis ground of each component and ac safety ground, WHILE THE COMPONENT WAS NOT CONNECTED TO ANY OTHER COMPONENT. Given that, what you were seeing was simply the voltage to which the component's circuit and chassis grounds (which are usually common) "float" in the absence of a direct connection to ac safety ground (such as via an interconnect to another component which in turn has a 3-prong power plug).

That level is typically determined by the happenstance of stray capacitances within the component between circuit ground/chassis ground and each of the two sides of the incoming ac line ("hot" and "neutral"). The most significant stray capacitances are usually in the power transformer. Sometimes intentionally present capacitors and/or stray resistance paths may also be significant.

A good quality ground isolator, such as those offered by Jensen Transformers, should solve the problem. Also see this paper at their site.

Regards,
-- Al