Out of curiosity, TS, why do you want to avoid audio transformers ?
I have found a power module that could make the AEA TRP2 battery-powered portable.
JFET, no transformers there. (verifying)
If transformers *are* your bag, I stumbled on something interesting with dual Cinemag (Reichenbach) transformers per channel.
70db of gain, clone of a Neve design, I believe.
The same team is also doing a tube model:
All available as kit or assembled
All are Mono units which can be ganged