BillTodd: Thanks for your reply.

I am indeed going to use one LM317HV per phase, I should of made it more clear in my 1st post.

I am going to be using my Astrosyn MY103H702 stepper motors, thease have a max current of 1amp per phase.

I am intrested to know what caps to use to stop or limit any voltage noise.

As wile testing without any caps the stepper motor wile static will hum.

Thanks for your time.