Hey ERX, welcome to the depot
. My first ADA rig was MP-1, Quadverb, IPS33 smart shift. I used (and still do) a Yamaha AM802 8 ch mixer to bring it all together (it has 3 fx sends so 1&2 to Quadverb and 3 to IPS33) so the fx are all in parallel. Power amp ADA B200s and 2 x ADA slant split stacks. Great rig. I bought a MP-2 when they came out (and sold the MP-1 to a friend) which is now my current live rig. I've since removed the IPS33 and added a MB-1 to the rack coz I played a bit of bass for a while. So now I use the MP-2 for guitar and, as my bass runs stereo (well bridge PU to tip and neck PU to ring of TRS jack), I can plug the bass bridge PU into the MP-2 and neck PU into the MB-1. I also bought a pair of Messa P112 cabs for the bass, which also sound great for guitar using the MP-2s cab sim outs (as the P112s have a tweeter).
The parts you need for the 3TM mod you have to source here
https://www.marshalljmpmodshop.net/ada%20mp1%203tm.htm MJMP gets the tube boards made and I don't think they are available anywhere else? as he designed them). He may be a little slow getting back to you as he's been told to lay low by his doctor after a health scare (so you may need to be patient, but he will return). You can also try to PM him (MarshallJMP) but he hasn't logged on here for a while (doctors orders).
3TM is interesting, lots more gain (but I never thought the MP-1 lacked gain
). Apparently you loose the clean tube aspect of the MP-1. And the MP-2 has even more gain so ADA included a noise gate in the MP-2 to cope... If you haven't already, check out Leon Todds reviews
https://www.youtube.com/watch?v=SHfS-w8pTzM