I have a Korg Electribe ES-1 MKII and an old MBox 2, using Ableton Live 9 as DAW. I want to set up the ES-1 via Midi and Audio to my DAW. The MBox only has 2 Inputs and Monitor, Headphone and SPDIF Outs, the ES-1 can only take analog input methods. I already found converters for SPDIF to Analog out, but not in. Are there any options i am not seeing to set those two up together?
You've misunderstood the way inputs and outputs work.
The output of one device is almost always connected to the input of another device. You don't connect inputs to inputs and outputs to outputs. You connect input to outputs.
It would look like this:
MBox S/PDIF Output -> Converter S/PDIF Input | Converter analog Output -> Electribe analog Input.
That said, you might compare the cost of the S/PDIF to analog converters with the cost of replacing the MBox with some other interface that has four analog outputs. It might be you can just upgrade your interface to something less than 15 years old.