Can OT's couple?

[sneakers563]

Hi all,
I'm building a K-12G in an aluminum chassis. I'll be mounting the PT (man, it's ugly) on top of the chassis and the OT's inside the chassis. They'll be mounted in a row (PT OT OT), with about 6 inches between the centers of the PT and the nearest OT.

Normally, I would orient the PT at 90 deg. to the OT's like so: | - -

However, given that the distance between the OT's is much smaller than the distance to the PT, and given that the chassis should screen the OT's from the PT, would I be better off orienting the transformers like so: | - |

That is, orienting the OT's at 90 deg. to each other? Is there a need to be concerned about the OT's coupling, or is there only and issue with PT-OT coupling?

[Ty_Bower]

Yes, OTs can couple, although the effect is far less noticeable than coupling with a PT. I understand the "recommended" orientation of the output transformers be with the laminations of the OT parallel to each other, not all in the same plane. It supposedly reduces the signal induced in one OT due to stray field leaked from the other, improving channel separation. The direction of the center axis of the winding probably has an effect as well, but I can't say what.

Do this:


Not this:


I would still keep both OT with the same orientation and have them 90 degrees with respect to the PT.

[pointy]

the l-l looks good the picture is of one of the better UK amps of the 60's (leak st20)