Phil Allison" wrote

** Autos have less copper losses and much better bandwidth than
a
isolation type.

Sometimes. Is that what ** means?

Wanna compare figures on a 4:1 impedance step down toroidal
with a
160 VA size core ?

Read the other posts that I agreed with. 4:1 is easy. 400:1 is
nearer what most people would use here. Neither would 160VA be
appropriate in most cases. Care to cite a reasonable comparison?
Care to back up your statement about "much" wider bandwidth, in the
context of an OPT for a domestic valve amp? Can you think of any
other important parameters other than copper losses and bandwidth?

Ever wondered why no-one uses, or supplies, auto-transformers for
valve amp OPTs?

cheers, Ian