Transformer position?

[888guitars]

Does it matter what direction the output tranny is facing? Is there a "N0-No" for how its placed?

I have the output tranny next to my 6v6 (about 1 1/2") will it matter if the primary or the secondary is facing the tube?

[MWJB]

Output tranny should have its laminations at 90deg to the PT, either vertically or horizontally. It makes sense to have the primaries facing the tube/PT, as this is where the primaries run to.

[R.G.]

The classical advice for mounting transformers and choke is that the center tongue of the laminations should all be at 90 degrees to one another. You have available X, Y, and Z directions (in threespace at least!) so the axis of the lamination tongues should all be mutually orthogonal. This provides the lowest possible pickup of leaked flux. Moving them farther apart reduces this further by reducing the leakage magnitude by the square of the distance they are apart.

You can also introduce soft iron "shields" between them to sop up some of the leakage, and put copper bands around the trannies to "short" the leakage flux.

Or all of the above.

Some amps will hum in the speakers with the output tubes pulled. There is enough leakage from the PT to the OT to put a low level hum in the speakers.

[jrfrond]

Some amps will hum in the speakers with the output tubes pulled. There is enough leakage from the PT to the OT to put a low level hum in the speakers.

Sometimes induction hum can happen with ferrous chassis, and finding the position or node where it cancels or is minimized can be a real issue with new designs. It can be a result of distance and/or relative position of the transformers. IF you ever see an amp with one of the transformers mounted at an odd angle, this probably was the case when the new design was tested and debugged.