| br>If you`re referring to a direct CV connection from Max to your modular, you should research if your Fireface model has a DC-coupled headphone output. The Expert Sleepers`website has a quite complete listing of DC-coupled audio interfaces. If your Fireface is among those, you`ll need something like an insert cable (1x1/4TRS to 2x 1/8TS or 6.3mm stereo to 2x3.5mm mono in Euro speak). If all goes well, sequencer putting out CVs as audio channels in Live, routing this channels exclusively to headphone out, cable working OK, you should expect aprox. +/- 4.5V of CV on both jacks.
If you just want to use gates or triggers with Max, you should be able to use all of the Fireface`s analogue outputs.
If your friends sequencer output is MIDI, you simply need a MIDI-CV module. br> br>