Sounds like you want to swap the 2 band eq in the 90 NT for a 3 band. If this is correct, you should just need to get the proper pots with the 3 band pre. As long as the bass has 3 holes, it should be do able. Customer support section should be able to help further if you post the question there.
Thanks Gerry that's exactly what I wanted to know... not sure I'll do it though as the sound, as is, is gorgeous. Thanks again.
Andy

