need a transformer

I am having all kinda of trouble with my setup. My steppers are acting
crazy but I am sure I have rounded my trouble down to the transformer.
I dont think its putting out nameplate amps. I am running three 6amp
steppers. I wouldnt mind having about a 25amp transformer that will
output about 75V. I am running my steppers through geckos, have
noticed (still a novice with stepper controls) that voltege makes a
slight difference but putting resistors on the geckos and limiting the
amps makes a major difference. Does anyone have an old transformer
that will do what I need? 25amp or so around 75V? send me a private
email if anyone can help me with one. I dont get a chance to look
through every post due to my work hours. rebel307@... is my
email. Shoot me some lines with some prices.
Jessie