Ground hum with AVR

The DMP6 is already having grounded power supply, so wondering what could be the issue as I’m getting the dreaded ground hum noise at high volumes of a connected AVR (Marantz SR7012), with RCA cables.

With same cables, there’s no noise at the same settings with the Naim Atom connected with the same AVR, so it’s not an issue with the latter.

 

All in the same wall-socket?

 

Yep.

 

The AVR PSU? Have you got balanced inputs option? if so give them a try, just in case the hum enters the system via RFI through the interconnects.

 

Unfortunately not. Just RCA. I don’t know how to engage support. Could be a faulty unit…

 

solution: RCA cable with the shield soldered to ground on one side and plug this side into A6

 

Tell me more: which cable do I solder and where do I plug it in the A6?

 

I made my RCA myself.
If you have a plug to disassemble, unscrew it and solder the cable screen to ground, usually the upper pin. And then you connect this side of the wires to A6 and the other side, where you did not make any changes, to the amplifier

 

I'm sorry, but... what is the difference: to transfer the audio signal you need both the live AND the ground/shield connected on both sides, as the shield is the ground/reference. What is the actual geometry and wiring of your hand-made RCAs? I'm curious, as I might have been missing something interesting so far.

 

https://www.bapihvac.com/applicatio...nd Loop,picks up interference currents easily.

 

np. czerwony czarny to plus, żółty i szary to masa, ekran albo nie jest w ogóle podłączony do masy z żadnej strony jak to zwykle bywa, albo jest podłączony tylko z jednej strony i czasami jest to tzw. kierunkowy, miejsce, w którym podłączasz go do źródła, strona, do której podłączyłeś ekran.

 

This is the case where you have a 2+1 (signal + gnd + earth/shield) cable, and in that case you are right that the shield may be connected ONLY ON ONE SIDE, and usually the transmitter's. Ordinary RCA interconnects have a 1+1 wire (signal + gnd/earth/shield) and in that case you are out of luck in leaving the earth disconnected.

 

dmp6 check the power plug and the wall socket. If you use a pin and not a schuko, then the chamfer is on the left, the neutral is on the right, and the protective one is in the middle, i.e. the pin or plates are in schoko.

 

Yes, having a ground wall socket is mandatory, at least at the beginning of the chain (e.g. the audio source)

 

that's why I never use a cable with one cable and ground 1+1 for RCA

 

https://en.wikipedia.org/wiki/Ground_loop_(electricity)

https://www.amazon.com/s?k=HiFi+Gro...ground+loop+isolator,aps,288&ref=nb_sb_noss_1

 

We’re looking for workarounds it seems. Can anyone from the product team (assuming they’ve time to lurk here) comment on earthing issues of the unit?

 

Well, it seems like the AVR is the source of the problem; try to flip its power cord? Change to another socket? Check its has earth connection?
Of course we are looking for workarounds, as everything else would involve the manufacturer to intervene... in these cases, it is almost always a matter of workarounds.

 

It isn’t the AVR as I’ve mentioned earlier up in the post.
And I meant if the unit is known for earthing issues (hence asking for someone from the product team to comment) instead of trying workarounds which don’t address the root cause.

 

Just to rule things out: is the Naim plugged itno the wall on the same socket tehA6 is? If not, try to use the same socket for the A6. It is clearly a ground loop, so if disconnecting the grounding between devices is not an option, see if we can get the minimal differential between outlets...