Phono stage hum - Rega Aria


Hi folks, trying to solve a hum issue and would appreciate any thoughts. Rega Aria phono stage, into a PrimaLuna Dialogue tube preamp, then to Bel Canto SS mono's. 

With the tonearm NOT plugged into the phono stage, there's a hum.(especially when set to MC vs. MM)
Rega powered off, no hum while preamp at max volume. Turn the phono stage on, there's the hum...I hold the phono stage in the air, 4 feet from everything, same hum. When I hover it over my preamp, the hum gets much louder due to interference. Magnaplanar 1.7i speakers very quiet until that phono stage enters the chain.

Haven't tried a cheater plug...but have tried 2 diff interconnects (Better Cables/Silver Serpent and BJC LC1) from the phono stage to the PrimaLuna, and 2 different power cables (Furutech FP-S022N and factory cable) into a Furman Elite 15-DMi. 

Either this Rega Aria is a noisy phono stage, or I've somehow got a ground loop in there with it. It's really not bad at lower volumes, but sucks when that hum breaks the silence at louder volumes between songs/sides. 
Opinion - is this phono stage a weak link in my system? Maybe it would be fine if I find a way to eliminate that hum. 

JA Michell Gyro TT
Rega RB 808 tonearm
Ortofon Cadenza Black cart
Primaluna Dialogue Premium preamp
Rega Aria phono stage
Bel Canto M500 mono amps
Furman Elite 15-DMi power
Magnaplanar 1.7i

Better Cables/Silver Serpent interconnects
Blue Jean Cables for phono and Maggies
Furutech FP-S022N power/outlet

Cheers, thanks for any advice! 
128x128malmc02
I'm using DH Labs BL1 DIY that I assembled myself. It's a two conductor with a ground. On the phono source end, the pos is connected to the pos RCA pin, the neg and jacket ground are connected to the ground pin. On the preamp end, just the pos and neg are use. The jacket ground is left unterminated. This is designed to drain ground away from the source. You can google for more info. It works for me!
Interesting, may try that! I have tried several diff cables already, but not with the grounding scheme you outlined. Thanks. 
Apologies to all for the lack of response since posting. I had some unexpected travel and was ill for several days ( no COVID thankfully).


@malcom2 I’d say it’s at a medium volume on up. I can hear it at below medium but really have to strain to hear it. I will be talking to the dealer in a couple of days to see what his resolution will be, including refund. (Sorry didn’t mean to hijack your thread !)

@conde64 I bought the Aria mkII based on the dealer info that it was “only” a cosmetic change. Interested to see if the MK III does in fact solve the hum issue. Fortunately my Aria is under warranty so we will see what resolution is offered up.

@dramatictenor Good info, I’d be interested in knowing which phono stages you tried so I don’t repeat the trial of same ones that don’t solve the problem.
New P10/Aria Mk3 combo-purchase.  MC Hum.  Going to call dealer Mon and see what they say.