interconnnect for tri-planer arm?

I have a Triplaner/ZYX Universe combination and am interested in possible tonearm/innerconnect possibilities.

I am very happy with how things sound now, but interesting to hear form those who have upgraded.

Are upgrades made behind the tonearm or wiring all the way back to the headshell. Not sure about what the arm/cable interface would intail

I was looking at the Morrow PH cables as a possible option

intrested in your insight

thanks

Tom