Choke orientation

[firemedic]

Is it important to orient the choke laminates perpendicular to the OT laminates?
I have a TR chassis I'm trying to put a 100w Marshall style OT on, and it fits much better parallel, and right next to, to the choke. Will this position cause too much noise/hum?

[kagliostro]

To me seems that is important the orientation of the OT with respect to the PT

so if you put the choke perpendicular to the PT and the OT perpendicular to the PT

the OT will be in parallel with the choke

so I think is better to have choke & PT parallel and OT perpendicular to both PT & choke

Kagliostro

[firemedic]

Due to the flat  "in-chassis" PT mounting in a Blackface chassis, all 3 can be perpendicular to each other.

[HotBluePlates]

We can know from Fender practice that the stock Twin Reverb orientation doesn't have a noticeable hum problem.



In Building Valve Amplifiers, Morgan Jones points out that although chokes have an air gap, and therefore have significant flux leakage, the amount of a.c. across the choke is small compared to a PT or OT. For that reason, the choke won't leak a large amount of flux to induce hum in the OT.

The exception is a choke-input power supply, which has a large a.c. component across the choke. Most guitar amp power supplies are cap-input, however.

[firemedic]

Thanks!