How to manage other synths?

Quickly checked the manual, thought I figured out the question I was asking myself but cant seem to get it work right.

So, I wanna control my A4’s 4 tracks on my octatrack and another 1 for my AR.
I put up all THRU machines with corresponding inputs (A B - C D)
Then I push MIDI and give midi tracks the numbers of the channels I put up on the A4/AR.

Its setup like this;
on AR i put all 12 channels (what I can hear on the pads) to channel 1
on A4 i put T1 to channel 2, T2 to 3, T3 to 4 and T4 to 5.

I was hoping to process my main now from my AR a tiny bit on the octa on T 1 , and use the fader to switch between my A4 tracks (T2-T5). But it seems like it doesnt work this way? I cant seem to mute the different channels for the A4 tracks.
Only thing that seems to be muting is my AR pad 1 if I mute the T1 on the octa.

How to set this up correctly that it works like this?
Also how do I go about T1 on the octa for main AR and lets say T2 for pad 1 and T3 for pad 2 only. Is this possible?

Hopefully im making sense in trying to explain this.

It’s hard for me to understand your question exactly … but I try …

What I guess is that you connect the audio-out from your A4 and AR to the audio-in of the OT and hooked them up on THRU machines correspondingly.

With this you can use the OT like an audio mixer. What you can do is to create scenes A-B where the audio-tracks of the OT are muted or un-muted and fade between those scenes.

Now it reads that you want to use the fader of the OT as a MIDI-controller for your external gear. AFAIK the fader works between scenes of the OT and transmitts CC45. CC45 can’t be used to mute/unmute tracks on the A4/AR directly. Example: the AR has CC94 mapped to mute a track.

I recommend to check out the MIDI implementation of all three machines. It’s in the appendices of the manuals.

If needed the required translation could be done by a midi-processor.