there was no sol'n I found which sounded as good as the simplest wind. Making the leakage lower only hurt the sonics. The bench specs of the interleaved item did look pretty good. the sonics left much to be desired in comparisons to other applications and implementations.

This was quite counter-intuitive for me. Even as I was wiring the things up, I was convinced the lower leakage wind would sound better. I was immediately dissapointed. Some fairly extensive experimentation followed and the conclusions were solidified and more clearly classified.

A nickel core with a two bay bobbin, one bay reverse wound wrt the other so that the turns next to the center tap are up against the core is on my list of things to try. .007" SuPerOrthoSil is a nice Iron to wind with but its perm is not quite like Nickel...
regards,
Douglas