Help With System hum, Please


I have a hum in my system at higher volume between songs at when lower level imformation on a song is being played.It sounds like an amplified sound coming from the speakers.
My phono pre is a Zesto Andros (stock tubes)turntable is a VPI superscoutmaster,cartridge is a dynavector XX2mk11.The cable between the tt and phono stage is an ortofon phono cable and then cardas golden ref going from phono stage to the pre.

I have tried running extra grounds from the TT with no luck.Could the stock tubes be the problem?The tubes are JJ's.Any suggestions would be great as this is driving me crazy.I have eden sound terra stone footers on the TT.

Being new to vinyl, I have another question.Should the stock powercord going from the vpi sds to the outlet and the pc going from the sds to the tt be replaced with after market power cords?I am not sure what to try next to solve this problem.
Thanks in advance
moonguy
When I was talking to Jim McShane about quiet 12AX7 tubes for a phono preamp or tube dac and he suggested the Sovtek 12AX7LPS. They are inexpensive relative to other tubes. Maybe try those in place of the JJs after you are done re-done the cabling of your system?
I had a similar situation where only the phono was picking up some electrical line noise; no noise with the CD or the DAC, and I'm using the Zesto as well... I was able to eliminate the noise by adjusting the ground switches on the back. I ended up with one side up and the other down.... Not sure of all the reasons (although I do have an inclination) but was able to eliminate most noise, now it's back to a very quiet tube system, using Cary SL-05 pre and Cary 805AEs for amps.