Building a 5F6-A

[Mick Bailey]

My own view, having had Bill Kirchen use one of my amps for a number of shows and him asking me to build him one, is that the minutiae of a transformer construction becomes irrelevant in the grand scheme of how an amp sounds overall. The amp Bill uses when he's here has standard Hammond transformers and not one mojo or boutique part.

[Helmholtz]

^^^^ Couldn't agree more.
My go-to amp is a Fender '63 VV RI, which uses a very basic OT (125A6A) judging from its size and the large leakage inductance of 90mH.
I also have a '59 BM RI, which uses a much better spec OT. Never liked this amp, but it makes a great extension cabinet for the Vibroverb.

Who says that Hammond doesn't use appropriate interleaving?