transformer based guitar bass recording channel

Here's the recording channel that is being built these days. I wanted to learn some more about impedance issues concerning guitars, bass and amps, and there's no better way to learn than to build something. So off we went.zoom in on picture for details.active DIs on each input, with different transformer options. class A circuitry, balanced, two filters and two send/return with blend option. This unit will consist of independent buildingblocks, so that it is easy to modify and swap certain parts later.