I understand. Do you think your RCA to XLR Cables might fix the slight buzz issue?
It may help, but it doesn’t fix that it is not wired correctly internally. VTV does not seem to understand how to properly do it, despite it being explained. Unfortunately, whoever they are using to assemble these units looks to be getting worse at soldering rather than better.
Look very closely at the diagram in rerit's post (#2 in this thread), as it shows how it should be properly done; as it isn't apparent without looking very closely at the diagram:
1) On the interior of the case, the amp board to the XLR connector, you run pin 2 & 3. The shield
does not go to pin 1. It goes to a case ground, with each to a separate ground in the case and as close as practical to the XLR connector, but not connected to it.
2) Pin 1 of the XLR connectors should be grounded to the case at the nearest point possible to where the XLR connector connects to the case. Some XLR connectors have a built in jumper where Pin 1 grounds to case when installed (this is what March Audio uses).
3) The amp and Pin 1 grounds to the case should not be tied together (i.e a star ground). Each should be tied to case separately, so a total of four connections to the case.
The reason this is important is that you are trying to keep noise from getting inside the case to begin with. The pin 1 connection from the source line is supposed to send any emf picked up in the shield to the case. The shield from the amp board is supposed to go to the case, again because you are trying to get any emf out and away from the amp modules. When you wire it the way that VTV has, two things occur. First, you have just routed all the emf picked up by the shield directly into the amplifier and to the board. Second, you have created many more potential ground loop issues.
Most of the time, the improper wiring is not an audibly noticeable issue. The problem is that when it is an audible issue, it is nearly impossible to fix if the wiring isn't does correctly. This is why Rane and AES developed and recommend the AES48 wiring procedure, as it is best practice and eliminates the problem. Unfortunately, many, many, many manufactures do not implement it properly.
If you look at the post I made here, you will see how the XLR wiring looks in the VTV when done in accordance with RANE, AES48, Hypex requirements:
https://www.audiosciencereview.com/...its-all-amirs-fault.13195/page-14#post-467536