Crumb wrote:

On a UTC a-25 line output transformer, the frequency response is 40hz-
20Khz. The tranny is designed for DC in the primary of 8ma. Is this
frequency response rating derived with DC on the primary?

Yes.

If this is
the case, would using this transformer in an AC-coupled situation,
increase the low-end frequency response?

Maybe a little, but not much. It has a split core.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."