I am not sure I understand your question... I use a EAR 834P tube phono pre with stepup transformers... nice!
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I believe that some of the Audionote (uk) phono stages are transformer coupled (referred to as balanced output). These are truly cost-is-no-object designs, so there must be something good about using transformers for the output. Audionote uses transformers for the output of their DACs as well.
I suppose the other way to reduce output impedance, aside from CJ's use of parallel output tubes, would be a cathode follower, but, there are enemies of that design choice too.
Paulfolbrecht, there is another way of getting a low output impedance with tubes. called the Circlotron. It is not commonly used in tube preamps, mostly because of patent issues. But a tube preamp using a Circlotron can drive 32 ohm headphones- in effect making a nice headphone/phono integrated. And no transformers.