Help! New Nagaoka MP 500 Cart Makes Hum Ground Noise


I have the new Nagaoka Mp 500 cart installed on my Techniques 1200G turntable connected to my Luxman 595 amp. When I turn the volume up, I hear a hum in the speakers. If I remove the cart from the arm, the hum goes away so I know it's the cart. It's with the original Techniqs head shell. I didn't have the issue with the Oltofon 2m Black LVM cart. 

Aside from that, I like the MP 500 a lot. Sounds good. But I am freaking out... not sure what to do about the hum grounding noise?!?

On my luxman, I have both the turntable and the REL sub on the ground in the photo. 

Here are the photos on imgur https://imgur.com/a/yEwvvAq

dman777

@dman777 new details emerging now. You didn’t mention hum on the other inputs.  No you should not have that noise with your Luxman. You are dealing with ground loop or electrical interference. You need to figure out what it is. 
Are you using RCA on all source or XLR on digital?

@audphile1 xlr connects on the streamer. But the hum is only there if I have the turntable RCA cables plugged in, regardless of what input I have selected on the amp. But the hum is a lot less loud when it’s not on the MM input.

I have to emphasize that if I unplug the turntable RCA plugs, It gets rid of the hum completely regardless of what input I have the amp set on. Then at that point I have a true black background again as before I ever got to turntable hooked up.

If you unplug XLRs and keep the table plugged in, what happens to the hum?

Do you have a spare set of RCA cables you can try on digital so that all your connections are RCA?

Is the streamer/dac plugged into to the same outlet as amp, table and sub?

Did you check if outlet is properly grounded?

Was there any hum at all with the Ortofon cartridge?

I have been building my own interconnects for a while now. After completing a PH16 build I started having a hum. My usual interconnect was with Dueland cotton covered OFC into Switchcraft 3502AAU connectors. I ended up switching to Mogami W2549 in a directional format. This has eliminated all of my hum issues from turntable to phono stage to preamp. 

@dman777 Just throwing out a few things -  Does your Luxman have subfilter adjustment for the phonostage section? If  so ,have you either turned it on or off to see if it helps with the hum?  Are you sure that you have the ground cable securely attached on the TT end ?  Maybe double check.  You indicated above that you think there’s an issue with the supplied Tt cables have you tried a different set of phono cables to rules that possibility in/out?