01-06-15: Charles1dadAgreed, Charles. My comment should not be taken as implying that the output transformers are not "good," or are not capable of providing fine performance when paired with suitable speakers. My comment was speculation as to the reason, or one of the reasons, for the high output impedance. Nothing more, nothing less.
I suppose it's possible to have good quality transformers that suffer unusually high output impedance.
Best regards,
-- Al