You have a ground loop issue. Neutral is grounded at the main electrical panel box however the length of cables and a poor contact somewhere (or a cheater plug) to the equipment can allow a small stray voltage to build up from some power supply leakage to ground (coudl be a faulty component). An RC interconnect will provide the return for a small stray current and hence you will induce a hum in the line level signal. With RCA you always have this problem to a greater or lesser degree - although the hiss or hum may often be low enough not to be of significance in a system with low dynamic range.
Why is a 1.5-2 volt AC signal on my Neutral line?
I have several music sources e.g. DVD, Phono, DAC, Tuner etc...
I just purchased a NAIM integrated amp and I am experiencing a hum but only from the DVD player.
I have circuit tested the entire house wiring and all is well.
After a lot of investigation I found that some units have a 1.5-2.0 volt AC signal (sounds like a 60Hz signal i.e. hum) between the neutral side of the interconnect and the earth at the power bar.
Panasonic, Pioneer and Sony units I have measured all have this signal present and it varies between 1.5 - 2.0 volts
Luxman and Cambridge Audio gear does NOT have the signal present
All units have a polarized plug with no ground pin
How can the hum be eliminated using the Pioneer DVD with the NAIM Amp?
Thanks
I just purchased a NAIM integrated amp and I am experiencing a hum but only from the DVD player.
I have circuit tested the entire house wiring and all is well.
After a lot of investigation I found that some units have a 1.5-2.0 volt AC signal (sounds like a 60Hz signal i.e. hum) between the neutral side of the interconnect and the earth at the power bar.
Panasonic, Pioneer and Sony units I have measured all have this signal present and it varies between 1.5 - 2.0 volts
Luxman and Cambridge Audio gear does NOT have the signal present
All units have a polarized plug with no ground pin
How can the hum be eliminated using the Pioneer DVD with the NAIM Amp?
Thanks