I'd like to hear someone having tried to use a power transformer as output
transformer for the single-ended final stage of a tube communications receiver
(power 5W, maximum, frequency not higher than 4,500 Hz).

As a matter of fact a plain power transformer with a 220V primary winding and 6V
secondary winding would well match a 4-ohm speaker to a 5400-ohm plate load.

Basic questions:

1) does the DC current flowing through the transformer create problems? (do
proper audio tranformers have a gap in the magnetic path to avoid saturation?)

2) would a typical transformer work up to 4500 Hz, while maintaining the
expected impedance ratio?

3) would modern tranformers wound on a toroidal core offer better performances?

Unfortunately, proper audio tranformers are getting scarce these days.

Thanks and 73.

Tony I0JX