Its possible to direct-couple preamp outputs too.
Transformers need to be loaded correctly; if loaded too lightly (impedance they are driving is too high) they can express more of the inter-winding capacitance and less of the turns ratio. This can result in a peak somewhere in its response curve. If loaded too heavily you can get a bit of a roll-off at higher frequencies. This might not be much of an issue since its pretty easy to get good bandwidth at line levels. But you might want to ask Kevin what impedance he regards as ideal for them to drive.
Transformers need to be loaded correctly; if loaded too lightly (impedance they are driving is too high) they can express more of the inter-winding capacitance and less of the turns ratio. This can result in a peak somewhere in its response curve. If loaded too heavily you can get a bit of a roll-off at higher frequencies. This might not be much of an issue since its pretty easy to get good bandwidth at line levels. But you might want to ask Kevin what impedance he regards as ideal for them to drive.