low-level background white noise - Parasound Halo JC-3+

Summary:
I’ve got an issue with the background noise that I can’t seem to figure out. It’s white noise, there is no 60 hz hum present at all. So, I don’t think it’s a grounding problem. If I turn up the JC-2 on the JC-3+ input to 100%, I get 61db of white noise (c-weighted, slow response) from the listening position (about 12 feet from the speakers). There is a faint 60-hz component, but it’s mostly white noise. (It’s not pink noise). That test is with the tonearm cable disconnected from the system. 

My system:
Me: 51 year old 30-year audiophile with tested 35 year-old ears. Excellent hearing in both ears.
Linn LP-12 Radikal/Keel/Ittok LVII/Dynavector XX2Mkii/Audio Origami phono cable
JC-3+ set in the MC Variable position at 100 ohms loading
JC-3+ with Belden XLR cables to the JC-2 as well as Goertz single-ended cable (A/B testing)
The rest of my system is a Linkwitz LX-521 based system driven by Emotiva XPA-5 Gen 2 amps in an analog active cross-over config. It’s irrelevant to this conversation in my opinion.

Here’s my problem:
Parasound JC-2 on input 1 with the volume control set at the 9 o’clock position. (or 25%). This is normal volume and produces about 75 db music at the listening position. White noise is clearly present, I’d estimate it at the 50 db level. It’s about the same level as when the HVAC is pulling air through the vents.
Inputs on the JC-2 positions two thru six are dead silent all the way to full volume.

Here’s my test chain of events:
Disconnect the 90 degree connector from the LP-12. White noise still present.
Disconnect the Audio Origami phono cable completely. Connection from JC-3+ to JC-2 only via XLR. White noise present.
Replace the XLR cables with RCA cables. White noise present. Substitute different XLR cables, white noise present.
No cables on input one of the JC-2 (JC-3+ disconnected). No white noise present. Dead silent.

I tried reversing polarity via the switch on the JC-3+, but this doesn’t help.
Both channels have the exact same level of white noise in all of the above tests.

Any ideas? Is this normal? Am I being too critical? Is there something I haven’t thought of?