Line amp with switchable output transformers

[Seeker]

I was wondering if there was a pcb / project floating around for a line amp with switchable output transformers, and then an attenuator so the transformers can be driven hard if desired. I know people have built things like this and I don't wanna re invent the wheel here if there is already a project that covers all this... I'd like to be able to switch between 4 or so different transformers.

I am looking to use it as a color / saturation tool for my final mixes...

Thanks!

-Jason