Physical orientation of transformers

[bereanbill]

First, thanks to everyone who has generously shared their knowledge with this tubenoob...LOL...When laying out a new design, what factors should be considered when positioning the transformers on the chassis ? Aside from the obvious advantage of positioning them for easier, shorter wiring, what else should factor in. I seem to remember positioning trannies so the windings were 90 degrees from each other...presumeably so the leakages didn't get mingled or whatever? How does this come into play when say the PT is horizontal and the OT is vertical ? Thanks in advance....

[zigzagflux]

Hello from a fellow Berean:

I have found that rule of thumb to have limited success. My best results came from energizing one transformer (ideally the PT), and connecting my scope up to a high impedance (high voltage) winding on the other transformer, and watching the induced signal produced on that second transformer. That way, you get an idea of which orientation truly is the best.

For a recent build of mine that used an input xfmr, 2 interstage xfmrs, OPT, and 2 PT's (that's per monoblock), I found not only the correct orientation, but found that some transformers were relatively immune to induced pickup. I could orient those in the 'wrong' manner with say one of the IT's, without adversely affecting my pickup. Furthermore, those that are constrained to be either in a certain plane or orientation, you can experiment with what minimum distance is ideal to negate the effects of nonideal orientation. You will usually find that you can't make all the xfmrs happy all the time, so compromises are made. This method allows you to pick your battles, and minimize the compromise.

Are you using signal transformers (input, IT), or just PT, choke, and OPT?

[bereanbill]

To Zigzagflux: My area of interest is Guitar amplifiers for the most part. So PT, OT, and choke. I am a relative TOOBNOOB with no formal training and a short attention span...dangerous combination. Any help is always appreciated, but please use small words, ok..LOL !!!