So I made a few more measurements. One of the issues with measuring noise is having the probe itself capture them. To avoid that, we use what is called a "differential probe." As the name indicates, it measures what is different between the two wires. Most noise that couples into the cable will be the same on both leads so will be reduced a lot in level.
Here is what happens when I use the differential probe and measure what is going on between the chassis ground of my analyzer and the negative pin of the balanced audio connection:
So we have little noise.
The next one is an odd measurement. I measured the noise between the analyzer chassis again, but the other pin is touching the wood part of the terminal coming out of the back of Entreq. I am using this as a baseline of what noise is bleeding into the measurement system physically:
As expected, we now see some noise because the end of the cable is essentially dangling "in the air" next to Entreq.
Now I connect the probe to the metal part of the Entreq terminal with the wire moving a fraction of an inch:
That's right. The moment I connect the terminal to the Entreq, the amount of noise that the system measures goes up. This is consistent with the previous measurements that showed noise being picked up by Entreq.
Now there can be two reasons for this increased noise. The stuff that is in Entreq and the length of wire. The latter will act like an antenna and feed noise into measurement system.
To tease that out, I just connected the probe to the lead of my multi-meter which is sitting on my desk, unpowered:
Now we get even more noise than what Entreq produced. That is to be expected because my meter probe is longer than the length of wire that is inside Entreq.
So coming from an entirely different path, we see the same workings. All that is going on here is a piece of wire part of it inside Entreq, and part of it outside leading to our audio equipment. Its characteristics only allow it to pick up noise, not eliminate or reduce it in any manner.
What say you?
