I think it's very risky, you will void your warranty 'n stuff and all other arguments put here by other elektronauts not to do it.
this is the second machine with too little outputs.
The octatrack only had a stereo out and a cue output that was designed to be a monitoring out. Luckily elektron gave us 'studio mode' in order to have 2 stereo outs and divide the 8 tracks over them. (still want 4 mono... grrr)
Now the A4 just has a stereo out. I would think elektron would have gotten the message lots of people want a lot of outputs, like the monomachine or the machinedrum.
Regrettably this isnt the case
I'm having the feeling elektron wants to push, or maybe nudge, people into the trinity concept. Just hook up those elektron boxes to eachother on the inputs of the octatrack and you can go live.
Well, they misdesigned the octa on that point as well.
If you have an A4, machinedrum and a monomachine, the octatrack just doesnt have enough inputs :P.
I realy hope elektron opens their eyes on this part and will give future machines more outputs.