Sunpak DX 8R Ring Light/Macro Flash compatibility to new dslr?

Did not realize and purchase a Macro flash that was made for film slr cameras
It comes with a Nikon adapter. I have read forums that stated older flash has higher voltage sometimes

I found out the nikon d3100 is a 250 v
the sunpack is 6 volt

but then I also read the the trigger has a different voltage which is usually lower
but I can't find anywhere that tells me the voltage of pc socket on the nikon
any input?

What you are asking I think is all about trigger voltage. That is the voltage that the hot shoe on the camera sees.

A 6v trigger voltage is excellent since any and all dSLR cameras can use that flash.

If you had a Canon dSLR, and the flash trigger voltage was over 6v, you could burnout the cameras electronics.

The fact that the Nikon D3100 can take up to 250v, means that you could connect it to studio flash units without any worries.