I got the sorta kinda general idea, but not what to do in practice. I have an amp project, a Supro Thunderbolt S6420 in a JTM45 chassis. The two transformers, PT and OT are both stand up. So the cores will both be perpendicular to the chassis. Not sure I'm using the correct term, thought "core" meant the steel laminations that the windings are around.
Read through a few posts, but didn't get the conclusion, mostly because the amp was a different shape. The PT was a laydown, so its laminations were parallel to the chassis, and the OT was standup, so the laminations were naturally 90 degrees (assuming that they didn't rotate the OT).
With both cores standing upright. what is the best relative orientation of the two? And do they need to be some distance apart, or can I mount them closer together?
I sort of understand that in a general sense, you don't want the varying B field of one transformer to induce into the other one. This PT has end bells but the OT does not.