I found a blue Akai MPC1000 for cheap and i am in the process of restoring it.
The blue, old style MPC1000 has a few issues: old style pads behave erratically and the encoder has just seen better days.
The old encoder vs new encoder: the old plastic body one is impossible to find, and the new metal encoder requires you to mod the pcb to be usable.
I have installed JJOSXL on my Akai MPC1000.
The form factor differs slightly in these two encoders.. more on that later
Disassemble the Akai MPC.
Solder in the new one, using great care
Make sure the new encoder is flush on the pcb (slight physical difference with the old plastic one).
Now using some solid core wire, make these connections:
Check if the bridges have been successfully implemented using the buzz feature on your multimeter, then reassemble.
Switch your Akai MPC on, and press MODE+the OTHER pad.
Access to the ENCODER menu and select NEW TYPE.