Thread Limits and compatability of using a 1st gen Scarlett 18i20 with a 2nd gen 18i20?

Well, I ended up buying a Clarett 8pre and tried connecting the 18i20 (in stand alone) to the Clarett via ADAT. I had clicking and popping issues that you can read about in their other thread (linked below), but I ended up with a working solution.

https://en.audiofanzine.com/focusrite/forums/t.10833,best-way-to-use-scarlett-2i2-scarlett-18i20-1st-gen-and-clarett-8pre-all-at-once,post.24258,new.1.html

I have exactly the same 3 questions...! Lol

PL

1: first of all when connecting two machines...
They need to be synchronized. One is master.. Second is slave
So in a way they are never stand alone if you use more than one machine.

2: you can't control both by the focusrite software.
That will say : you will be able to control 8 additional inputs like an octo pre by the adat ports. If stand alone 18i20 I would say you have to route your analog ports to adat ( so you can only use 8 of the 18) so that the The first machine sees a signal on adat.

Or make a pre mix and route that to adat.

3: the app
I guess that is a gen2 thing and the first generation will not be able to listen to the app.

Myself use a 18i20 with an octo pre dynamic.
Giving me 16 analog inputs ( 8 are controlled by adat) and 16+ analog outputs or 8 stereo)

So my answers are based on what I think the machines and software are expecting.
If you what 8 additional inputs /outputs I recommend an 8 channel dac/adc with adat inputs and outputs.
( the dac will be slave and can be controlled by the focusrite software - routed and premixed)

In my opinion it is rediculous to use a complete 18i20 as dac for just 8 extra channels.

But again..

I hope the fine gentlemen of focusrite can give you more insight in this matter...and I hope you will find the answers to your questions.

- Angelie