That design is terrabad for at least two reasons: 12AX7s don't make very good followers: the gm is quite low, and the current sourcing capability is way too limited.
Secondly, you have your Bax circuit inside the gNFB loop. That means that your NFB will try to "undo" what the tone control is trying to accomplish. Lastly, do you really need that much open loop gain? If you're trying to make a hollow. state op-amp, there are better ways to accomplish that
It also looks like this is set up for positive, not negative, feedback.